SHINING STAR is a shared-multiverse setting for Daria fanfiction. Rather than being an actual world, the setting is a timeline of events depicting a long-term disaster scenario with a science-fiction theme. The events occur on and around Earth in the writer's chosen Dariaverse. The writer determines exactly when the event occurs and who the event affects.

A supernova erupts in Earth's immediate stellar neighborhood, very close to our Solar System and with no warning. This has nightmarish consequences for human civilization, not to mention the rest of the biosphere. The catastrophe unfolds in timed, specific stages, ranging from a multitude of events occurring within a single day to subtle events gradually manifesting themselves over many months or years. The very existence of terrestrial life down to the smallest microbe will repeatedly be placed in jeopardy. A description and chronology of the supernova disaster follows. Links are provided in the text to external websites providing additional information.

You ask, why bother to do this? The practice in creating websites is helpful, for one, and doing research and writing science fiction are two of my great loves. Developing shared worlds for fiction writing is also lots of fun, and (finally) I like to blow things up. That pretty much covers it.

And if you don't write fanfiction or any other kind of fiction, just read and learn something about what happens when a supernova goes off at close range. Enjoy.

 

NON-INTERNET BIBLIOGRAPHY & REFERENCES

 

 

A Few Words about Realism

 

A great effort has been made to detail the effects of a near-Earth supernova as accurately as possible, according to the latest revelations of science. However, the study of supernovae—the correct plural is not supernovas—is yet in its infancy. Much disagreement over supernova processes exists in the field. The most recent research indicates that more Type Ia supernovae are created by stellar collisions than by accretion (explained later), but the information given here still appears sound.

Many effects given here are extrapolated from sparse data and educated guesswork. For storytelling purposes, less attention is paid to giving out hard numbers (how much of the ozone layer is destroyed with each arriving shockwave, how far background radiation will rise during the later flood of cosmic rays, etc.), and more is paid to descriptions of likely consequences and their potential magnitude.

One problem encountered in working out this scenario was the discovery that many sources make little distinction between the effects of core-collapse and thermonuclear supernovae. The news media and even some scientists will take an effect specific to one type of supernova and generalize it to all others. (This scenario does it, too, when no other information is available, but you are being told about it up front.) This confusion is a real pain when working out the realistic consequences of an explosion. No burst of neutrinos will herald this supernova, and no neutron star, magnetar, or black hole will be left behind. Those are core-collapse supernova effects, not thermonuclear ones. Further, no Type Ia supernova was ever known to produce a gamma ray burst, believed by some to be the consequence of a hypernova or neutron-star collision. Several references used here appear to confuse gamma-ray bursts with supernovae, making matters worse.

We are not poorer for the loss of such special effects. In every source consulted for this work, Type Ia supernovae are always noted as being more dangerous than any other sort. A core-collapse supernova even at relatively close range (say, 10 light years) is a far more survivable event than a Type Ia burst occurring many times farther away. So of course a Type Ia supernova at very close range is the only sort that will do for this setting.

 

 

 

As for choosing van Maanen's Star as the source of the supernova, it should be pointed out that much of the little that we know about this celestial body is derived from a limited amount of data taken from direct observation. Some data are derived second- or third-hand from the previous figures, increasing the margin for error. And some data were determined by comparing this star to similar ones, assuming they were alike, then performing extrapolations. There's nothing wrong with doing this so long as one remembers that error magnification is a consequence. As van Maanen's is a solitary star, its true mass is not known with great accuracy.

There is also the influence of the unexpected, recent discoveries that add new dimensions to our knowledge of space. Peculiar types of white dwarf stars and unusual supernovae have appeared in the news of late, and van Maanen's Star could have odd and ultimately lethal characteristics of which we currently know nothing. The chance that van Maanen's Star will explode appears to be slight, given our present state of astronomical expertise, but disaster cannot be ruled out.

The bottom line is this: This webpage describes, in fiction, an event within the realm of possibility. In this scenario, it will happen no matter what. Van Maanen's Star will rip through this entire end of the Milky Way Galaxy, and Earth will be right next to it when it goes. What happens next is up to you.

 

 

The Daria Connection

The SHINING STAR scenario may occur at any point in time of the writer's choosing, in any given Dariaverse. Several aspects of the Daria series are of potential interest in story development, including elements in Lawndale itself.

Granted, this scenario can be used for any sort of fanfiction or fiction writing. The anime Stellvia of the Universe would be perfect. Don't let me stop you. A tip of the hat would be nice in return.

The existence of extraterrestrial aliens is often hinted at in Daria, either through the Sick, Sad World TV show, UFO conventions ("Esteemsters"), or the delusional rantings of Artie, the pizza guy. Should the writer decide such aliens actually exist and possess faster-than-light travel, these beings will undoubtedly be aware of the coming explosion and will take pains to leave Earth before the first shockwave arrives. They might leave behind scientific data recorders, their garbage, or unwanted fellow aliens. One or more alien spacecraft might take on passengers before they leave Earth (perhaps involuntarily, if hijacked by desperate humans). Kindly aliens might stay long enough to pass along technological secrets to enable human civilization, or parts of it, to survive. And why is Principal Li collecting DNA samples from students and fortifying Lawndale High School?

 

 

Another consideration is the "wormhole" behind the Good Time Chinese restaurant in Lawndale, and whatever extradimensional worlds (and beings) lie beyond it. The writer is left to decide whether the wormhole exists and what role it will play in the coming disaster (preventing it, making it worse, etc.). The canon Dariaverse had other peculiarities, any of which might be of interest here. Use your imagination.

Finally, alternate Dariaverses are often equipped with superheroes, advanced technology, time travel (remember Shaggy?), magic, and the like. Many alter egos used in the show suggest the same. And there is always the tesseract issue. Again, the writer is the final authority in deciding what unusual powers and devices will be employed in the tale. The only rule is to never write anything boring.

 

 

Whatever fandom world is used with this setting, a caveat must be offered. If the writer's universe includes the human use of interstellar travel and human-colonized worlds, note that other colonized worlds in the Solar System receive the same effects as does Earth, but lack the atmosphere and magnetosphere that shield humanity from the most dangerous effects. Mars in particular would be lethal terrain, though deeply buried colonies there and on the Moon might hold out for a while.

In addition, van Maanen's Star is closer than we are to certain stars long celebrated in speculative astronomy and science fiction because of their similarity to our Sun—and the presumed possibility that they have Earth-like planets. These worlds will tragically receive far more intense exposure to the supernova's effects than Earth will get. A table showing the distance from van Maanen's Star to various stellar systems is given at Solstation.com.

Tau Ceti, at the unfortunate distance of only 6.2 light years from the supernova (and about twice that from us) will receive five times the amount of radiation that Earth will. Epsilon Eridani is in a similarly bad fix, receiving about twice the radiation heading for Earth. If humans or aliens call either of these worlds home, they can hang it up. Refugees from either world might stop briefly at Earth before continuing their flight out of the danger zone, a minimum of 32.6 light years from the supernova (= 10 parsecs).

 

 

 

White Dwarfs

White dwarf stars have been known to science for less than a century, being first recognized in 1910. By 1917, only three were known; more were not discovered until the 1930s, and it took until the 1950s for over a hundred to be found. Presently over 9,000 have been counted.

A white dwarf star is often called a stellar remnant, dead star, or degenerate dwarf. It is all that remains of an extremely aged main sequence star, the most common sort in our galaxy, that has passed through its red giant phase and burnt up all its hydrogen. The red giant then collapses into an Earth-sized ball of densely compressed matter that shines with a white light. White dwarfs are not terribly uncommon in this part of the Milky Way, but they are hard to find as their light is so faint. Though they are brighter per unit of surface area than our Sun, their total surface area is so small that little overall light is emitted. It takes billions of years for a main-sequence star to become a white dwarf, but a white dwarf will burn many billions of years more before cooling completely. The special physics of white dwarfs—how it is possible for them to be so dense, how they manage to generate energy—need not concern us here, but the interested reader may start here for an in-depth view.

 

 

Most white dwarfs are thought to have about .5 to .7 times the mass of the Sun, with examples known down to about .17 solar masses and up as far as 1.33. It is easy to estimate a white dwarf's mass if it is in a carefully observed double-star system, allowing an orbit to be calculated and relative masses to be compared. A white dwarf's surface temperature is deduced from examining its spectrum (using a telescope and prism), its distance from the Sun can be figured out from its parallax, its overall luminosity from the distance and brightness, and its radius from complicated equations using assumed values for mass (assuming also that the white dwarf is "typical" in other respects).

Now a problem appears. Unlike a main sequence star, a white dwarf does not follow what is known in astronomy as the mass-luminosity relationship (the more mass a star has, the brighter it is). A white dwarf's luminosity has no relationship at all to its mass. Instead, it has a mass-radius relationship: the more massive a white dwarf is, the smaller it gets. The more mass added, the greater the gravitational pressure on the materials that make it up and the more compacted such materials become. If you crash planets into it, it actually shrinks. Add too much mass, however, and it explodes, as will be seen.

A solitary white dwarf, then, has only its spectrum, luminosity, and parallax for direct, measurable data. Other particulars about it must be conjectured by comparing it to similar white dwarfs with more reliably known characteristics. The room for error is relatively great, and it is rare for different studies to produce the same results for the same star. This point becomes critical in the next section, where it is revealed that big surprises come in small, dense packages.

 

 

Type Ia Supernovae

 

Supernovae are complex and horrific phenomenon. Two basic kinds are known: core collapse and thermonuclear. A core-collapse supernova occurs when a star having at least nine times the mass of our sun has aged to the point where it has exhausted much of its nuclear fuel, gradually producing a core of superheated iron. When this core reaches a certain mass limit, the core implodes for an instant, then rebounds in a titanic explosion. All that is left of the original star is but a remnant: a neutron star or black hole. No stars in the immediate neighborhood of our Sun appear to be progressing toward the core-collapse stage, though a few farther away might be.

The thermonuclear supernova is of interest here. A thermonuclear supernova is better known as a Type Ia supernova. (Type Ib, Type Ic, and Type II supernovae are of the core-collapse kind.) A Type Ia supernova is believed by some astronomers to occur when a white dwarf star continuously accumulates interstellar debris on its surface until the total mass of the star reaches a critical point called the Chandrasekhar limit, named for the astronomer who discovered it. This mass limit is about 1.4 times that of our Sun. At this point, the white dwarf has enough heat and pressure to fuse the carbon that has been accumulating at its core—a waste product, much as iron is a sort of waste product in larger stars as noted earlier. When carbon detonation occurs, the white dwarf explodes and is completely destroyed. Nothing is left but a super-hot shell of expanding gas called a supernova remnant.

 

 

It is thought that the most likely way for mass accretion to occur is for the white dwarf to be in a close orbit around a red giant star, close enough to pull away the outer envelope of material from the much larger star. A white dwarf in a contact binary star system, in which two stars are so close that they touch and exchange matter, could also lead to a supernova.

An alternative theory that received recent scientific support holds that a collision between two white dwarf stars, perhaps as part of a double system in decaying retrograde orbits, will also trigger a thermonuclear supernova. One recent supernova is thought to have been triggered in this way.

Other means of achieving the same end might be possible. The SHINING STAR shared setting explores one such alternative, a combination of the above two scenarios. The deciding factor in most theories appears to be the final-stage mass of the white dwarf in question. How the star gets there is less important than this.

Core-collapse and thermonuclear supernovae are immensely devastating but differ in their effects. The core-collapse kind emit huge numbers of neutrinos and ultraviolet light in the initial explosion. The amount of visible light emitted by a core-collapse supernova, when plotted over time (the so-called "light curve"), rises to a maximum after two and a half weeks, then slowly fades. For some reason, the decrease in visible light after maximum might suddenly stall, with the remnant giving off about the same amount of light for many following days. The slow decrease in light eventually begins again and progresses until the star is completely gone.

Thermonuclear supernovae do not emit neutrinos, but do give off extreme amounts of x-rays and gamma rays in their place. Early on they have about the same light curve as core-collapse supernovae, but they reach a much greater brilliance and decrease in illumination about twice as fast as core-collapse types. No plateau is seen in the falling light curve. So far as can be told, Type Ia supernovae operate on a very predictable schedule with very predictable results, being so uniform in appearance that they are currently used as benchmark devices to determine intergalactic distances.

 

 

 

 

 

As astronomy buffs are now surely aware, it was announced in January 2010 that a peculiar white dwarf called T Pyxidis has been showing signs it might shortly (in galactic terms) erupt as a Type Ia supernova. It lies about 3,260 light years away, which (in galactic terms) really isn't that far. While this might indeed be a problem for us (or maybe not), our scenario demands more drama. T Pyxidis might not go off for 10 million years, anyway, and what good is that?

As it so happens, a white dwarf in our galactic backyard is much better suited for this scenario. It is unlikely this star would soon blow up as a supernova, as most estimates of its mass place it below the Chandrasekhar limit, but the interesting possibility remains.

Discovered by accident in 1917 and named for the astronomer who found it, van Maanen’s Star has attracted attention for almost a century because it is one of the closest stars to the Solar System, at 14.1 light-years. It is a white dwarf, believed to be about the Earth's size in diameter but many times denser and more massive. Once a part of the main sequence, this star long ago went through its red giant phase and reached an upper limit of 1,000 times the diameter of the Sun. Its hydrogen exhausted, the star swiftly collapsed into its present form. It is approaching our Solar System at an oblique angle, guaranteed to safely pass by us in the far future. However, it is so small and faint that it cannot be seen with the naked eye, and it will probably still be invisible except to telescopes even at its closest approach. It has a high measurable proper motion, meaning it moves at a great speed through the interstellar medium relative to our Solar System. In galactic terms, it is merely flitting by.

A 1974 analysis of the star’s properties established the value for its mass at 0.7 ± 0.3 solar masses, allowing for the possibility it has a mass equal to the Sun's or even greater. As van Maanen's is a solitary star, its mass had to be estimated (with a significant margin of error) based on an estimated value for the star’s radius, which itself had to be inferred from its measured brightness. A reliable measure of its mass does not exist. Some later studies have lowered the upper limit on presumed mass, but some have raised it to .83 or .84. There is much room for creative play.

 

 

Spectroscopic studies indicate this object is relatively cool, compared to most white dwarfs, and thus is extremely old. It might have spent over 4 billion years in its current state, making it an ancient star indeed. If so, it might have circled the core of our galaxy over a dozen times.

One analysis of van Maanen’s Star suggests that it has more heavy metals on its surface than is usual for such a body. It is possible that this star has already absorbed a large amount of cometary material or even former planetary bodies torn to pieces by tidal forces when they got too close to the star and hit the Roche limit. (The study just cited suggests van Maanen's Star might still have a planetary system, though there is no evidence of dust encircling it.) This metallic material might also be the remains of rogue planets or other matter in the interstellar medium that had the misfortune to cross van Maanen’s path. Given the star's presumed great age, it could have picked up quite a large amount of matter during its many orbits of the Milky Way’s core. If its mass is very high, its radius will be very small (for a white dwarf), which we would have no reliable way of knowing. As a side note, the lack of dust and gas around this aged star will allow the coming explosion to rocket through the local interstellar medium at full speed, unhindered by collisions with debris.

Van Maanen's Star has a long list of other names, most being un-sexy strings of alphanumeric characters from astronomical catalogs (e.g., WD 0046+051). Its most common alternate name is van Maanen 2 (abbreviated as vMa2), as it was the second star that van Maanen the astronomer discovered.

A last factoid: Van Maanen's Star lies near the center of the zodiac constellation Pisces. Every day, the entire Earth makes a full rotation beneath it, with the equatorial regions most directly exposed—an important point to keep in mind for later, when the star blows up.

 

VAN MAANEN'S STAR: LINKS ON THE INTERNET

 

 

Van Maanen's Star (center)

 

Stellar Demolition 101

For the purposes of this shared universe, it is assumed that the mass of van Maanen's Star has long been underestimated by astronomers. It is possible (just brainstorming here, nothing more) that van Maanen's Star was once part of a close binary star system and accumulated a great deal of matter from a red-giant companion. In time the close passage of yet another star disrupted the pair and flung the white dwarf away on a high-speed solo flight through our galaxy's arms. As it traveled along, van Maanen's Star accumulated yet more mass from collisions with rogue planets and other space debris. In any event, its mass slowly approached the Chandrasekhar limit but did not cross it.

Now for the final touch. There is intense debate in real-life astronomical circles over whether this star has a very large planet or sub-stellar companion in close orbit around it. The matter has not yet been resolved and awaits final data from more accurate direct observation. In view of this, we assume van Maanen's Star also has a single huge planet orbiting a short distance from its primary, an enormous gas giant unable to shine under its own light and too dim to yet be detected by telescope. The lone planet, about 10 times the mass of Jupiter, is in a decaying retrograde orbit, having been picked up by chance somewhere in interstellar space. (This is the same mechanism thought to have brought the giant satellite Triton to Neptune.) The immense body creeps closer to its parent with every passing moment.

About 14.1 years before the scenario begins, the doomed giant crosses its parent star's Roche limit and is slowly ripped apart by tidal forces. Most of the material from the satellite body collides with the white dwarf. The Chandrasekhar limit is quickly reached. Carbon detonation occurs and the white dwarf is annihilated. The star's destruction could take as little as a minute's time, though one source gives the process one second to completion.

The explosion blasts into dust anything near it, including other celestial bodies. An intense, roughly spherical shockwave of light and high-energy radiation flashes outward and heads for, among other places, Earth. Additional shockwaves follow over time: a long, fluctuating surge of gamma radiation from radioactive decay in the blast's debris; one huge, long wave of cosmic rays, generated within the stupendous explosion and moving at sub-light speed; and a blast wave of diffuse physical matter, mostly glowing superheated gas and microscopic dust swept up from interstellar space with staggering amounts of x-rays, gamma rays, and cosmic rays to boot. Each shockwave is a killer. If anyone is left alive to see the final one roll in, that blast wave might be the last thing any human ever experiences.

 

 

 

A Critical but Tricky Technical Point

A writer who nitpicks at details might wish to know exactly where the supernova will first appear over Earth if it goes off at a certain time the writer has in mind. Conversely, the writer might harbor a secret dislike for one side of the Earth and wish to have that side catch the initial radiation blast coming in from van Maanen's Star. This is obviously an important story element. Larry Niven proved it in his science-fiction tale, "Inconstant Moon," in which Europe, Africa, and Asia get roasted by a solar flare, but Los Angeles comes out okay, relatively speaking.

NOTE: You may cheerfully ignore this section, but you might be nitpicked by reviewers unless you can cleverly word the story to avoid pinning down the supernova's exact timing. It's up to you.

Van Maanen's star lies near the center of Pisces (the Fish), a faint constellation known to astronomers since Babylonian times. It is not a particularly interesting spot for most sky observers. Curiously, ancient Greek myths connected with Pisces link it to the birth of a horrific monster, Typhon, which attacked the gods themselves.

Any amateur astronomer will tell you that stars rise in the east and set in the west. Because our clocks work on a 24-hour day, but the Earth's rotation is actually 23 hours 56 minutes, a particular star will rise four minutes earlier every successive night. This is why certain constellations, like Orion, are quite visible at night during winter but not particularly so during summer. The point is that if the supernova appears in a particular spot in the sky at a particular time of day or night, it will be seen to change slowly position as weeks go by. This makes it a bit of a problem for storytelling, but luckily this issue can be fixed.

 

 

Van Maanen's Star by chance lies very close to the First Point of Aries, the place on the celestial sphere where the celestial equator and the ecliptic cross. In astronomer's terms, that spot is 00 hours Right Ascension and 00 degrees Declination. This is where the sun is positioned in the sky during the spring (vernal) equinox, about March 20-21 each year. If by chance the van Maanen supernova blows up near the spring equinox, it will first appear very close to the Sun and won't be visible at night. That would make the supernova hard to detect, but once the source of the disaster is learned everyone would know exactly where it was for a while.

For practical purposes—simpler here is better—we will let van Maanen's Star occupy roughly the same spot as the First Point of Aries (which used to be in the constellation Aries but has since moved to Pisces, for reasons not worth discussing right now). The writer can now do one of two things:

Remember, the supernova will appear almost directly over the Earth's equator because of its position in the heavens, though it could be either day or night when it shows up. Where on the equator (and which side of Earth gets slammed first) is the tricky point.

 

 

Resourceful writers with astronomy backgrounds will likely have astronomy programs on their computers capable of showing the positions of the stars and planets at any particular time of year. Everyone else must use the Internet, which offers a few quick, clean, automatic star map makers. The writer goes to the website, enters the desired location on Earth and the time of interest, clicks the mouse, and a star map appears showing what's overhead at that moment. Remember, the map is valid even in daylight. Just because the sun hides the stars doesn't mean they aren't there. With the star map, one can check celestial coordinates for the First Point of Aries or just look around for the word PISCES to figure out where van Maanen's supernova will be, or learn if it is even visible to viewers at that time and place. Two of the better online star-mappers are:

YOUR SKY (Fourmilab Switzerland)

WEATHER UNDERGROUND: Astronomy

The writer must play with the star-mapper a bit to get van Maanen's star in the right spot, if a right spot is needed. It's easier, if less satisfying, to just pick a time and live with the results (or fake it). The above mapmakers also allow the writer to pick a city of interest instead of putting in geographic coordinates, so all that is needed is to decide to which city the suburb of Lawndale is attached.

That settled, we move on to the consequences.

 

 

 

 

It is believed in the popular mind that the first detectable sign of a supernova is always its visible light. This is not precisely true. Before this supernova can be seen with the unaided eye, a gigantic pulse of lethal ionizing radiation will reach us, the first of several destructive waves of energy and matter. We shall take events in the order in which they occur during the first day of the supernova's "arrival" at Earth.

Keep in mind that the early discovery of widespread radiation exposure is more likely to be seen as an act of war or terrorism than a natural event. At best, it might be thought to come from a nuclear-related accident. It will take time for even knowledgeable people to get a grip on what is happening, as the supernova's effects are so bizarre, widespread, and devastating.

 

 

Dead Space

Gamma rays, hard x-rays, and ultraviolet light from the supernova's first apocalyptic moments bathe Earth and the Solar System in staggering amounts. The duration of this radiation torrent has not been measured for thermonuclear supernovae, so guesswork must be involved. A variety of loosely related cosmic detonations suggests a short duration. An explosive burst of x-rays from a Type Ib supernova (SN 2008D) was measured at only 400 seconds duration. The neutrino burst from SN 1987A lasted less than 13 seconds start to finish, and a recent gamma-ray burst (GRB) aimed at Earth was timed at 15 seconds. Lacking information for type Ia supernovae, we set an upper limit on the hard-radiation shock at five minutes. The burst might last only one minute, but its impact is stupefying and unlikely to be turned aside by extrasolar magnetic fields, given the short range.

An aside: one source estimates the duration of the initial radiation blast from a core-collapse supernova as lasting one day. If a prolonged radiation burst is found to be true of a thermonuclear supernova, the effects below would be so magnified as to wipe out almost all life on Earth in short order. Not much story in that. Until better information is available, we will use a shorter radiation-blast duration.

When the radiation hits, outer space becomes a graveyard for astronauts and cosmonauts, who suffer catastrophic radiation poisoning and die almost immediately. All spacecraft cease functioning, their electronics and solar-power systems overwhelmed and destroyed. Even systems armored against solar flares fail against a burst of gamma radiation equal to about 53,460,000 simultaneous solar flares (using this source and the inverse-square law). X-ray levels equal that from over 190 solar flares at once (determined using the same source and method as earlier). Exposed objects in space become hideously radioactive for years.

Every nation abruptly notices something is wrong following the loss of nearly every manmade satellite in existence. A tiny handful of close-orbiting spacecraft might happen to be on exactly the opposite side of the Earth from the explosion and be shielded from it; only those are able to function. Communications satellites transmitting telephone, cell phone, TV, and radio; navigation satellites offering GPS tracking; military satellites engaged in surveillance; weather satellites tracking storms—all of these fail at once. No reason is immediately found for this event. Manned space centers lose contact with all space travelers and all spacecraft in an instant. Deep-space exploration craft and orbiting telescopes stop sending data. Telemetry screens freeze, go blank, or record errors.

If ground controllers have power (see below), and anyone decides to match up the exact times that all the satellites went off, it is discovered that spacecraft on the side of Earth closest to Pisces went offline seconds before the rest. The last spacecraft to die were those closest to the other side of the zodiac, near Virgo. Interplanetary craft are affected as well, and in the same manner. The shutdown process was extremely rapid, implying the cause was moving at the speed of light. A possible clue as to what happened is being recorded by ground-based radio telescopes engaged in research, which note a sudden surge of energy from the general direction of the vernal equinox point in the heavens.

 

 

Nova Burn I: Radiation Sickness

Another global event occurs at about the same moment the satellites die, but almost no one notices it. Every human and animal caught in the open on the side of Earth facing the supernova suffers radiation poisoning. The blast of hard radiation reaching Earth is so incredibly high, not all of it can be stopped by the magnetosphere or atmospheric absorption. The nitrogen/oxygen blocking of gamma and x-rays by the upper atmosphere is not foolproof: radiation is reduced exponentially by any shielding. However, anyone (animals included) covered by at least six inches of lead, steel, concrete, or even water are unharmed, as radiation is further reduced by those barriers to tolerable levels. A skin diver in a bathing suit, five feet underwater, will get less radiation than a hat-wearing, fully clothed beach stroller.

Having no hard data at the moment on how much ionizing radiation normally gets through the atmosphere to the ground, we assume gamma radiation equal to 100-300 REM (1-3 Sieverts) is absorbed by each unprotected being as a full-body or partial dose. Creatures and plants living nearer the poles or the terminator (day-night line of twilight) at the time of the eruption are more likely to be saved by natural and artificial terrain blocking the rays, plus have more atmosphere available to stop the radiation (assume mild radiation sickness). Those living nearer the equator, directly below the flash, are less fortunate (moderate radiation sickness). Chromosome damage will be extensive.

Anyone flying in aircraft at altitudes over 20,000 feet on Earth's supernova side takes a much higher dose, being less protected by the atmosphere than those below. We will assume an average dose of over 4 Sieverts for anyone in this predicament, which will vary with circumstances (severe radiation sickness).

The most common physical symptoms noticed by those with mild or moderate radiation illness are fatigue, nausea, weakness, headache, and loss of appetite developing over a half day. Those with moderate sickness also have vomiting and some hair loss. The lower the Sievert dose, the less debilitating the symptoms and the longer the delay until symptoms appear. All of these symptoms disappear after a day or two, though further complications are coming. Severe radiation sickness produces nausea and vomiting in less than an hour, bloody diarrhea, headache and high fever, extensive hair loss, dehydration, and exhaustion. Wounds will not heal properly and infections are difficult to fight off. Again, these symptoms disappear after a day or two as the body enters a latency period, with further effects making their appearance later (see "Breakdown"). Irradiated people are not radioactive themselves, and nothing they wear or carry is contaminated. All will suffer serious health issues in the near future.

Radiation detectors of any sort on Earth's supernova side record a huge burst of energy from no particular direction, lasting the duration of the radiation flash. Badge dosimeters immediately change color to the most critical level of exposure. Outdoor radiation alarms near nuclear facilities are triggered.

 

 

Nova Burn II: The UV Flash

Adding insult to injury, the gamma and x-rays briefly produce enormous quantities of ultraviolet light at lower altitudes as a consequence of their deep ionization of the atmosphere. This brief ultraviolet flash on Earth's supernova side passes largely unnoticed by unshielded humans in the open, though extremely painful eye injuries become apparent within hours, leading to temporary blindness and long-term vision problems. Exposed humans with very pale skin may soon notice a painful reddening over their bodies, as if from a mild first-degree sunburn. Chromosome damage from this intense UV exposure is assured.

It was once believed that no animals possessed ultraviolet vision, but of late this has been repeatedly proven false. Birds, rats, turtles and lizards, many forms of marine life, and even a species of bat have been shown to see into the ultraviolet for a variety of purposes. The greatest users of ultraviolet vision, however, are insects. Bees follow terrain and select certain flowers using reflected UV light, for instance.

Though humans won't see the UV flash, many living creatures react violently to it in surprise, fear, pain, and confusion. Many birds and insects briefly lose their ability to navigate, blinded by the flash. The writer should check the Internet for information on UV vision for particular species.

 

 

Bright Lights, No Power

Moments after the satellites shut down, the sky over the side of the Earth facing Pisces (and the supernova) fills with rippling, rapidly moving light. Tremendous colorful auroras of red, green, and blue rapidly spread from both poles to the equator. The auroras are so bright they can be seen in the daytime as fast-flowing rivers and curtains of glowing pastel hues that twist from horizon to horizon. Night ceases to exist even on the side of Earth turned away from the supernova, as the skies from pole to pole blaze forth so brightly it appears to be dawn. The auroras are most active above 50 miles altitude, energized by the vast radiation flood ionizing high-altitude air molecules.

 

 

Radio and TV receivers using signals bounced from the ionosphere now carry only static. X-rays and gamma rays from the supernova completely disrupt the ionosphere after flowing down from the over-full van Allen belts. Worse, secondary particles from atomic collisions between radiation and atmospheric molecules shower down in vast amounts over Earth's supernova side, creating a sudden and vast electromagnetic pulse. The pulse temporarily overloads and shuts down power grids, and permanently destroys many microprocessors and electronics units on Earth's supernova side. Many computers and communications systems malfunction, except for military systems heavily armored against atomic warfare or the rare power grid shielded from severe solar storms. (Because of its brevity this event, though debilitating, is less severe than a similar event outlined in a related shared universe, DAYLIGHT.)

Whole regions lose power; only direct current (batteries) works. The repair and replacement of computer and power systems will take days at the very least. Once the first great pulse of radiation has passed, new electronic devices may be manufactured to replace the old, if power can be restored to the manufacturing plants and new materials shipped in. The side of the world facing away from the supernova is unaffected.

 

 

Hot-Air Turbulence

The sudden and deep ionization of Earth's upper atmosphere has another quick-acting effect: air turbulence. Heat is produced as a byproduct of the ionization of nitrogen and oxygen, and a lot of heat now radiates toward the ground from the sky above. Though the heated air is not enough to burn anyone, it is more than enough to disrupt jet streams at high altitudes and create catastrophic clear-air turbulence over wide areas. Aircraft crews unknowingly suffering from severe radiation sickness are further challenged by savage wind shears in every direction.

Most of the heat radiates away into space from the upper atmosphere, but some moves down as the vast amount of radiation ionizes the air to deep levels. Ground temperatures on the supernova side of Earth rise by a few degrees within the hour. The heating is uneven and chaotic. Weather patterns swiftly change, creating fast and violent ground-level gales, rain, and thunderstorms.

A recent study dismissed the idea that supernova-produced gamma and cosmic rays would generate significant upper-atmosphere heating, noting that a supernova would have to occur within 3.26 light-years of Earth to create severe turbulence. However, the study made use of a core-collapse supernova model. As stated earlier, a thermonuclear supernova emits magnitudes more gamma radiation than a core-collapse sort.

 

 

Invisible Fallout

Gamma rays are capable of creating photonuclear reactions when they strike atmospheric molecules. Radioactive isotopes of many elements (carbon-14, for instance) would be produced in abundance by the initial radiation from van Maanen's Star. The background radiation will rise worldwide within days as these isotopes are carried away by now-violent upper-atmosphere winds. While this "fallout" does not pose an immediate threat, long-term genetic damage is inevitable. Mild radiation poisoning might occur in a few areas with the ingestion of radioactive particles.

 

 

Supernova Smog

It was pointed out earlier that gamma rays sleeting deep into Earth's atmosphere will ionize molecules close to the surface and produce excessive ultraviolet light. This process generates a new, low-level layer of charged particles some have referred to as a "second ionosphere," capable of disrupting local atmospheric chemistry. The main byproduct of this second ionosphere will be ozone and nitrogen-oxide smog, which will be described later. It takes less than a day to notice the change in the odor of the air.

 

 

Second Sun

 

Though some of the above events will not become apparent for a time, the groundwork for them is well laid by the time the supernova finally becomes visible. The supernova's luminosity skyrockets from the start, but at baseline van Maanen's Star is about 600 times fainter than the faintest star the human eye can detect under the best conditions. It takes perhaps a minute after the radiation burst arrives before the supernova becomes noticeable as an out-of-place star that grows swiftly brighter. Type II supernova SN 1987A reached visibility within three hours of exploding. With the lack of interstellar dust between Earth and van Maanen's Star, the light should arrive unhampered. (Supernovae in our own galaxy have taken place in historical times without being seen, thanks to thick, intervening clouds of dust and gas.)

Within ten minutes the supernova is notably bright, well above baseline visibility. There is a chance it will be mistaken for an aircraft, a planet, a UFO, or any one of a thousand other things. After six hours it gleams white, outshining everything in the sky except the Sun. There is no mistaking its strange nature. It can be clearly seen in bright daylight unless close to the Sun. At night it becomes brighter than the full Moon and casts well-defined shadows. The explosion continues to grow brighter as the distant blast area expands, enlarging the effective area of illumination.

Incredibly, the supernova will not peak in brilliance for another two and a half weeks. After that, the light will slowly dim as the material in the blast area grows more diffuse, cooler, and less energetic. All the visible light after the initial burst is generated by the successive radioactive decay of nickel, cobalt, and iron atoms in the supernova's blast-driven debris.

 

 

 

The Whole-Earth Ozone Hole

 

The most devastating blow taken by Earth on the supernova's first day does not manifest itself immediately. The destruction of the ozone layer in the stratosphere is a complicated event that plays out over time. For ease of reference, much of the information on this sub-disaster is given here.

Theoretical studies have established a maximum distance from Earth that a core-collapse supernova must be in order for significant ozone destruction to take place from gamma radiation and cosmic rays. This radius of danger has been established as 26 light-years (8 parsecs). Van Maanen's Star, however, is only 14.1 light-years away, and it is a thermonuclear supernova.

The intense gamma radiation flooding in from the supernova causes a mass photodissociation of nitrogen molecules in Earth's upper atmosphere. Nitrogen ions combine with oxygen molecules and ozone to produce nitric oxide, nitrogen dioxide, and other "odd nitrogen" compounds that reduce oxygen and ozone in the stratosphere through chemical catalysis. Though the ozone is depleted, the nitrogen compounds are not. The end result is a progressive, large-scale destruction of the ozone layer, which absorbs 97-99% of the dangerous ultraviolet-B radiation Earth receives from the Sun. Much of the ozone on the side facing the supernova will be photodissociated in the burst, so there will be a quick initial drop in UV-B protection with a continuing decrease afterward.

A number of recent studies (1, 2, 3, 4, 5, 6, 7) have suggested that a gamma-ray burst within our galaxy would produce the effects described above. Studies of the aftermath of a nearby supernova (1, 2, 3) are very much in line with these results, allowing for a bit of extrapolation. Evidence supporting the creating of nitrous oxides by supernovae has been found in ice-core samples recently taken in Antarctica.

Computer models suggest that ozone loss could run as high as 50% after several weeks. How soon the ozone layer could repair itself is an open question. Solar ultraviolet radiation is responsible for creating the very ozone that absorbs it, so repair is a continuous process. One NASA study posits that five years after ozone destruction of this magnitude, 10% of the ozone would still be lost. However, the atmosphere is already contaminated by manmade chlorine compounds and nitrous oxides that have reduced the amount of ozone by several percent. Complete recovery from this comparatively minor damage, without further pollution or other difficulties, is projected to take 50-100 years. A major ozone loss could thus last for centuries.

The only good news is that the ozone layer is not immediately reduced to shreds, giving humanity a limited time in which to prepare for the looming disaster. Any number of astronomers and atmospheric scientists will be (indeed, already are) highly aware of the potential threat. Communication of the problem to authorities will be greatly slowed by the many other calamities in progress early on.

Each 1% drop in the amount of ozone in the stratosphere is thought to increase the amount of UV-B falling to the lower atmosphere by 2%, per NASA. The heightened UV-B will create more ozone closer to the ground (part of the "second ionosphere" mentioned earlier), which will again block some (but not all) of the UV-B. Unfortunately, low-altitude ozone is a well-known health hazard. It is strange to think that the ozone that causes so many respiratory problems for major cities would have a beneficial effect as well.

At first, because of the supernova's position over the Earth, most nitrogen compounds appear over the equator and destroy ozone there. These compounds are soon redistributed horizontally through Earth's atmosphere by high-altitude winds (made turbulent by ionization heat) and remain active in the stratosphere for years. After a year, however, the concentration of nitrous oxides will become greatest at the north and south poles, as these compounds are less subject to breakdown there. Equatorial compounds, by contrast, eventually move upward in the atmosphere and are destroyed. The drop in ozone over the equator at first would be about 50%, with the same figure becoming relevant for the poles later as the equatorial region begins recovery.

 

 

 

THE GREAT HUNGER

 

The first month following the supernova's appearance is one of the worst times for life in Earth's history. It is a period dominated by the sudden death of a large part of the food chain, starting at the bottom and working its way up. "The Third Horseman" covers the mass extinction in progress, but other dramatic events will take place through that awful month, too. We start with the appearance of the supernova itself.

Illuminated

The brighter the Type Ia supernova, the longer its light lasts and the hotter the explosion. Visible light from the van Maanen's supernova peaks 19 days after the burst is discovered. Astronomy nerds probably know a relatively bright Type Ia blast can reach an absolute magnitude of -19.5 (several sources agree on this figure), which we will adopt as the peak for the van Maanen's supernova. Absolute magnitude is the comparative brightness of an object at 10 parsecs (32.6 light-years), a standard widely used in astronomy. Visual (apparent) magnitude is how bright a celestial object looks from Earth. At a distance of only 14.1 light-years, the van Maanen's supernova will reach a visual magnitude of about -21.33. Our Sun has visual magnitude of -26.73; the full Moon is -12.74.

Skipping all the math, what does this mean in practical terms? It means that at its peak, the van Maanen's supernova is over 2,000 times brighter than the full Moon and only 1/250th as bright as the Sun. Its appearance is unparalleled in human existence. Looking at the supernova with the naked eye is mildly irritating and creates lingering afterimages. The use of binoculars or a telescope to view it without filters risks mild, temporary retinal damage. The supernova is easily visible during the day. Outdoor objects have two distinct shadows, one from the Sun's light and a marginally dimmer one from the supernova, with a dark patch where the shadows intersect.

On the side of the Earth where the supernova shines down after sunset, night ceases to exist. The great light at its peak illuminates the landscape as if it were early morning, casting sharp shadows. The supernova turns the night sky to deep medium blue, changing to darker blue at the horizons. The star's radiance and frequent auroras wash out all normally visible stars and planets except for the very brightest. (The Moon is easily visible but seems shockingly dim in comparison.) In the supernova's light it is easy to read and even drive without headlights. Surviving animals, both diurnal and nocturnal, become irritable and seek dark shelter for sleep, as the light upsets their sun-based circadian rhythms.

A table showing the visual brightness of the supernova compared to other celestial bodies is given at the link below. Note the very long time in which it remains visible in the sky. Type Ia supernovae that are visible to the naked eye appear to change color as they dim. After its peak, Tycho's Star changed from white to shades of yellow, then orange, then red before it faded away entirely after 16 months.

 

 

 

Breakdown

People who received mild or moderation radiation sickness on the first day (see "Nova Burn I") suffer more physical problems after a week has passed. Victims develop anemia, excessive bleeding, weakness, paleness, lethargy, difficulty catching their breath, and difficulty resisting infections. Many suffer a variety of illnesses brought on by the temporary collapse of their immune systems. Those with moderate radiation sickness also have vomiting, bloody diarrhea, and dehydration, with more extreme versions of the above symptoms. With proper medical care, most of these people will survive.

Severe radiation sickness produces all of the above effects after 5-6 days, plus uncontrolled bloody diarrhea, bleeding that won't clot, and multiple internal infections. Victims are completely exhausted, lack an appetite, and have difficulty performing any actions. About half of these people die if given proper medical care; far more die without it.

The world's medical infrastructure is hard pressed to cope with widespread radiation poisoning. The only care many receive comes from friends or family at best, and no one at worst. Vertebrates that are exposed to radiation suffer the same symptoms as above. However, insects (such as cockroaches) appear unaffected. Small vertebrates like mice and rats escape exposure if hiding in buildings or underground.

 

 

Breathless

As mentioned earlier, the nitrogen-oxide smog produced by ionization of the atmosphere grows thicker as more ultraviolet B from the Sun pours in. Worse, x-rays and gamma rays flood local interplanetary space for months after the supernova appears. This hard radiation comes from the decay of isotopes of nickel and cobalt in the blast, and it too ionizes the air and contributes to cosmic smog production and the collapse of the ozone layer.

Confusion exists as to the actual length of time that high levels of gamma radiation will be present in the space around the Earth, bombarding the atmosphere. One source claims that for a Type II supernova, the gamma radiation could be significant for up to two years after the blast was detected on Earth, the levels perhaps peaking several times during that period as the source of radiation changes. We assume the ozone layer is eroded to nothing in a month's time.

Among the similarly named chemicals created in large quantities by the supernova's radiation are:

Numerous sources (1, 2, 3, 4, 5, 6) testify to the dangers of the photochemical smog now plaguing cities in industrial countries. The situation would be magnified by a nearby supernova as the air slowly acquires a degree of toxicity across the globe, not merely in the cities (which paradoxically suffer less pollution than usual if power grids were shut down early on). At first the sky remains blue and clouds white (perhaps with a yellow tint), but horizons worldwide acquire a dark yellow or orange cast. Sunrises and sunsets are colorful. The air also gains a bad "industrial" stink. And it keeps getting worse.

About the only positive thing that can be said of nitrogen-oxygen smog is that it reduces ultraviolet B radiation from the Sun, which would otherwise come straight through the shredded ozone layer. Unfortunately this does not happen while the ozone layer disintegrates during the first month of the supernova. The amount of nitrogen-oxygen compounds formed is not yet sufficient to either stop UV-B or lethally poison the atmosphere, though more than enough is made to cripple the ozone layer. Much worse smog appears as bombardment of the upper atmosphere continues beyond the first month.

By way of comparison, a 1952 smog disaster in one city (London) killed over 4,000 people in a matter of days, two-thirds of whom were over the age of 65. Possibly as many as 12,000 people ultimately died, by some counts. Infants and adults aged 45-64 suffered heavy casualties. Most deaths in the smog disaster came from pneumonia, bronchitis, cardiac failure, asphyxiation, and complications from preexisting asthma. Survivors experienced chest pains, inflamed lungs, permanent lung damage, many new cases of asthma, and possibly an increased risk of cancer (probably to the lungs and throat).

The global situation in the first month after the supernova is not as severe as the London disaster. People with fragile or compromised respiratory systems (infants, the elderly, those with severe asthma) do suffer mild to moderate symptoms, with an increase in fatalities and hospitalizations.

 

 

Fire in the Rain

Another chemical produced in the smog is nitric acid, which is water soluble and precipitates out in rain and snow. This is the classic acid rain that has today damaged so many buildings and forests downwind of industrial centers. Supernova-created acid rain becomes a serious global issue one month following the supernova's appearance, growing far worse with the coming of the cosmic rays.

The acid rain has a notable effect on the environment. Though manmade structures are durable enough to withstand it during the first month, vegetation is not. Leafy plants develop acid burns, soil nutrients are dissolved and washed away, toxic elements are released into the ground, and runoff water is made more acidic, killing microbes, worms, frogs, crustaceans, mollusks, and fish. Many birds and mammals that depend on fish for food must migrate or starve. Significant areas of forestation die, especially at higher altitudes. Exposed food crops pull through if farmers add more fertilizer and nutrients to the soil, though fruits and vegetables might be damaged. Nitrogen in large bodies of water produces oxygen depletion and toxic algal blooms. All these effects are unlikely to be evenly distributed over the world, with some areas suffering far more than others.

During this time, however, ultraviolet B radiation from the Sun is on the rise, with far more devastating effects than mere acid rain. The combined effect of this new calamity with all others brings horror to the world within two weeks' time.

 

 

The Third Horseman

 

At the same time acid rain falls that first month, vast amounts of solar UV-B, perhaps twice or more the normal level, reach the Earth's surface as the ozone layer fades. Until a sufficient amount of ozone or nitrogen oxides is produced to prevent this, the UV-B begins to wreak havoc in the biosphere. Though plants have been shown to develop protections against high levels of UV-B, a sudden rise in radiation is unlikely to be overcome. A 50% drop in ozone could double the plant-killing effects of UV-B. Plant growth is generally inhibited in any event.

The plant die-off is concurrent with an increase in sunburn, skin cancers, and eye injuries to higher animals and humans. Added to the burden of radiation injuries, worldwide air pollution, and acid rain, a swift increase in the death rate and a decrease in the diversity among surface-dwelling, swimming, and aerial creatures is unavoidable. Dead animals and people become commonplace in every environment. As UV-B increasingly burns its way through the kingdom of living things, something new wildly accelerates the spread of death.

Exposed microorganisms become vulnerable to radiation death in the heightened UV-B. The tiniest of creatures, who form the rock bottom of the Earth's food chain, are hammered almost into nonexistence. Photosynthetic phytoplankton in the seas undergo a massive die-off, slain by UV-B near the water's surface. With their sole food source gone, zooplankton—then increasingly larger forms of sea life—begin to starve. Vital microorganisms on land are destroyed as well, and the food chain there is likewise disrupted. Day by day larger creatures up the food chain are affected—microbes, then invertebrates and fish, then birds and mammals—until humanity itself is at risk a week or two after the supernova appears.

In short, Earth is being sterilized by its own Sun.

 

 

With the ozone layer ruined after the initial radiation pulse and in decay thereafter, food-chain recovery cannot occur soon enough to prevent the start of a full-fledged mass extinction. Within a week of seeing the supernova's first rays of light, every living creature on Earth is fighting for its life against starvation. Humans with stockpiles of preserved food must defend them or die. Stockpiles that were refrigerated were likely lost when the power failed on the supernova's first day.

Once it begins, the mass extinction progresses at an ever more rapid pace. Billions of humans and billions more animals die in the first month alone, coincidentally as the light from the supernova peaks. All living species at risk before the supernova are almost certainly wiped out. Diseases spread as the unburied dead rot. Medicines that require refrigeration become extremely rare in areas without constant power, though every medication is in short supply. Protective clothing, goggles, hats, sunscreen, and mouth-and-nose masks are required if anyone wishes to go outdoors in daytime without suffering serious injury. UV-B reflects from many surfaces, so standing in the shade does not save one's eyes.

On the other hand, traveling about at night is relatively safe if one does not count hungry animals, armed humans, disease carriers, foul air, and acidic rain where it occurs. All life is forced into a dusk-to-dawn waking schedule, upsetting normal biorhythms and producing irritability and poor judgment.

 

 

 

PURGATORY

This period is a tortured intermission between horrors. It lasts three to six months after the supernova appears. Nations and cities struggle against famine and rioting while attempting to restore emergency services, transportation, and communication. The chaos and panic of individual survival is the norm. Ozone layer recovery does not occur, though thickening smog blocks a small amount of UV-B from reaching the ground.

The decrease in human numbers is hard to calculate. With so many sources of food and medicine lost, and with the environment so hostile from so many causes, it would not be unrealistic to expect that fewer than one person in ten will live through the first three months after the supernova. Cannibalism might for a short time become widespread among desperate would-be survivors.

 

 

 

The bad news has not ended. Astronomers and astrophysicists have long known there are several stages to a supernova's eruption. Supernovae are the primary creators in the universe of cosmic rays, which move fractionally slower than the speed of light. The supernova-generated cosmic rays will reach Earth in notably great numbers about three or four months after the supernova appears, rising in intensity from there. They will turn our world into something far worse than a living hell.

If humanity has any hope of making it through the coming nightmare, action must occur immediately. Immense shelters must be dug, radiation shielding must be built, food must be stored, people must be organized. It is all or nothing. Humanity's existence hangs in the balance.

Alas, such desperate measures might indeed be for nothing. What has happened to this point will soon be remembered as the "good old days."

 

 

 

COSMIC RAY TSUNAMI

Cosmic rays, actual atomic particles traveling marginally slower than light, begin to arrive one or two months after the supernova is sighted. The first few are of little notice, but gradually the van Allen belts around the Earth begins to fill with charged particles, and some spill down to the ionosphere. Auroras become brighter, more active, and more frequent. The background radiation at ground level climbs.

The weaker cosmic rays are trapped or deflected away in space by solar or terrestrial magnetic fields. The more energetic ones drive right on to Earth. These particles collide with atmospheric molecules and break them apart, creating more nitrogen oxides that reduce the shreds of the ozone layer to nothing. Poisonous and corrosive compounds are created as well. The impacts also create a growing rain of secondary particles, among them a sort called muons.

Muons are produced on Earth all the time by cosmic rays. They pass through us at every moment and rarely cause harm at current intensities. Naturally generated muons are used as a form of super "x-ray" source to detect hidden cargo such as uranium. Scientists have even used them to study the internal structure of volcanoes. However, in the immense numbers generated by a nearby supernova's cosmic rays, muons would become the most terrible supernova byproducts yet, destroying living cells and DNA wholesale. Genetic mutations would become more frequent. Direct and prolonged exposure to concentrated showers of muons would be fatal.

 

 

The muon rain grows in intensity as increasing numbers of cosmic rays arrive. Exposed plants and animals grow ill and die. The muon rain reaches a horrific peak eight or nine months after the supernova appears, as cosmic rays moving at 95% the speed of light strike the Earth, but the rain could continue for a decade or longer as less speedy cosmic rays arrive. Fast-changing, brilliant auroras are visible worldwide at night during this time. Cosmic ray intensity declines slowly thereafter, but it does not become nonlethal until decades after the passage of the oncoming blast wave.

Muons are not like gamma rays. Gamma rays and x-rays can mostly be stopped by Earth's atmosphere. Despite their short lifespan, muons can go right through a wall of lead two meters thick. They are known to penetrate solid rock almost a kilometer deep and ocean water for over a kilometer and a half. Little is safe from them en masse, barring new developments in medical technology (to repair cell damage swiftly) or defensive technology (to block or deflect muons from shelters).

The second great mass extinction gains speed. The ozone layer, completely gone one month after the new star appears, remains gone thanks to the interaction of cosmic rays with natural and man-made compounds in the air. Muons gradually slay everything vulnerable to them that ultraviolet B does not.

 

 

Breathing Poisoned Soup

Anyone left alive at this point then notices something different when traveling outdoors: the air is becoming unbreathable. Unlike the smog that appeared early on in the disaster, the "new" smog grows thicker and more lethal as time passes.

It seems trivial in view of what has already passed, but an enormous influx of cosmic rays can change more than just the ozone in the atmosphere. Nitrogen and oxygen molecules are ionized, forming (as noted earlier) various nitrogen oxides and nitric acid. Clouds grow in number and take on a brown, orange, or reddish smoggy hue. Lightning becomes more frequent as the atmosphere becomes more ionized. Acidic, corrosive rain falls. Eventually an ugly, semi-permanent orange-brown haze and thick clouds transforms the Sun into a blurry bright spot in the heavens.

It is assumed here that, after six months' time, enough supernova smog will have been generated as to reduce the solar UV-B to semi-tolerable levels at the surface, at the expense of destroying the lungs of unprotected air-breathing creatures. Unprotected breathing produces severe coughing and excruciating pain as acid droplets enter the sinuses, throat, and lungs. Exotic chemicals give the air a foul odor and produce nerve deadening, confusion, and mental and emotional disturbances from poisoning. Respiratory ailments skyrocket without the use of filter masks and oxygen tanks, though muons will slowly degrade the oxygen in manmade tanks as well. Corrosive rain, now falling in large amounts, degrades stone, paint, and metals left in the open; buildings and other structures show serious weathering and erosion. Foul orange-brown ground smog obscures long-distance vision.

During the worst of the cosmic ray period, it will be very difficult for life as we know it to exist on the Earth's surface or even near it. Biodiversity in shallower seas is as vulnerable to destruction as land and aerial life. Survivors in deeply buried or armored shelters, or living in submarine vehicles and homes in oceanic trenches, might be the only ones with any hope. What sort of world they will inherit in the end, however, is another thing entirely.

Meanwhile, on the surface, the befouled skies are eternally overcast and the clouds stained orange-brown. The land and sea become nearly barren.

It then, perhaps, begins to grow colder.

 

 

 

THE ICE AGE COMETH?

This section is optional because its potential appearance is controversial. Though a thick cloud cover would increase the albedo of Earth, it is not a guarantee that it would create cold conditions below. Scientists disagree on this point, some believing a cold period would follow and some saying that warming of the Earth would occur.

Ice-age proponents believe the thick brownish clouds of nitrogen-oxygen compounds would outweigh warmth-producing processes. As the albedo of the Earth rises, temperatures below the clouds fall. The process is very similar to the global cooling resulting from thick ash clouds spread by massive volcanic eruptions or a hypothetical atomic war (the "nuclear winter" effect). Global warming is soon reversed. Snow falls here and there across the globe, though in lesser amounts in the short term than one might expect. (Cool air carries less water vapor than warm air.) Glaciers, mountainous snow caps, and especially polar ice creep over the centuries into once-habitable territory. Atmospheric moisture falling out as snow does not return to the oceans, causing the sea level to slowly fall and long-submerged lands like continental shelves to reappear. A new ice age has begun.

Warmer-earth arguments note that nitrous oxide, produced en masse by the supernova's radiation, is a major greenhouse gas. The heat pulse produced by ionization of the atmosphere early on, then later from long bombardment by cosmic rays and muons, could counterbalance any cooling trends. It is difficult to say which trend would win out. The writer may chose as story demands dictate.

 

 

 

If an ice age is concurrent with severe cosmic ray bombardment, only life in the deepest mines or abyssal trenches is likely to pull through. Survivors might question whether survival was worth it. Given the long muon rain, plant and animal life will be in short supply on land, and possibly mutated if it exists at all.

Even without an ice age, the climate will be severely disrupted, and local weather rendered unpredictable. High winds, severe high-altitude turbulence, smoggy air, violent storms, fast-moving weather fronts, and acidic precipitation make for hellish conditions the world over.

 

THE LATE ORDOVICIAN MASS EXTINCTION

 

 

FINAL IMPACT

The long-term aftermath of a nearby supernova is difficult to predict, but certain events are likely. Nitrogen oxide pollution of the air will gradually decrease. The ozone layer might regenerate to a fraction of its former strength after many decades or, in severe cases, centuries. The amount of ambient radiation in the space around Earth is the deciding issue. In the long run, when all supernova effects have passed, ozone will once more block solar ultraviolet B. The supernova-triggered ice age, should it occur, would continue unchecked for far longer.

On cold winter nights, the glowing remnants of the supernova creep across the sky from Pisces, forming a rough sphere of ghostly filaments faintly visible to the eye. A Type Ia supernova usually creates a shell remnant resembling a giant hollow ball that continues to expand even as it fades, its molecules and plasma dispersing in the interstellar medium. Between 200 to 1,000 years after the explosion, the supernova remnant is said to be in its free-expansion phase, characterized by an even ambient temperature inside the supernova remnant and the remnant's steady rate of expansion. Less material has so far been swept up by the blast than was thrown out by the supernova at the start. The length of time this state lasts depends largely on the amount of interstellar matter present.

As it happens, the Solar System is currently within a large, mostly dust-free realm of galactic space called the Local Bubble. This bubble contains hot plasma and little dust. It appears to be the byproduct of a long-ago near-Earth supernova called Geminga.

 

 

In the SHINING STAR scenario, the free-expansion phase of the van Maanen's supernova lasts until well after the physical shockwave from the burst arrives at Earth. There is good reason to make this assumption, as the supernova remnant from Tycho's Star (the Type Ia supernova referenced at the top of this webpage) is itself still in free expansion. Parts of the vast shell from this 437+ year-old supernova have run into dust and gas, but its expansion otherwise has been little hampered.

With 14.1 light-years of clear space between Earth and van Maanen's Star, little gets in the way of the blast wave. The highest speed detected for a supernova blast wave is reported by one source as one-tenth the speed of light, about 30,000 km/sec. This claim cannot be verified, however. Blast wave velocities of 20,000 km/sec have been reported in studies of young supernovae, but velocities on the order of 5,000-10,000 km/sec are more common still, especially in a dense interstellar medium. The 20,000 km/sec value (1/20th the speed of light) is adopted as the remnant's average interstellar velocity for this extremely energetic supernova, as a Type Ia supernova detonates with more force than a Type II.

A Fast-Moving Front

Figuring out the time the blast wave's leading boundary reaches Earth is simple: it hits about 282 years after the blast was first seen, with a margin of error of 5% at the writer's option (268-296 years). Great filaments of the remnant will glow faintly in the night sky right up to impact. They will not be seen in color; the colors in most astronomical photos are false, added to show temperatures, chemical composition, or velocity changes. The auroras spawned by the long impact are likely to wash out our view of the stars for years to come, though they cannot obscure the Sun or Moon.

The front of a supernova blast wave—we use this term to distinguish the physical wave from the previous radiation and cosmic-ray shockwaves—consists of gas heated to millions of degrees (Fahrenheit, Celsius, or Kelvin—pick one, makes no difference which). The gas is highly defuse and thus incapable of roasting Earth, though it is dense enough to efficiently sweep up nearly every little interstellar thing in its way. As it passes through the Oort cloud before reaching us, it accumulates new debris therein.

The problem is that the intense temperature of the gas heats up everything bulldozed along by it (cosmic dust, gas molecules, etc.) to such a degree that two things happen. First, x-rays are emitted in far-beyond-lethal amounts. Second, dust particles and atomic nuclei are hyper-accelerated by the blast wave impact and the powerful magnetic forces inside the remnant. These individual motes are transformed into yet more cosmic rays, which themselves produce more x-rays. Today it is generally believed that supernova blast waves are the primary creators of cosmic rays within any given galaxy. As the van Maanen's blast wave approaches Earth, x-ray radiation and cosmic rays once again climb to lethal levels in space, peaking as the front of the blast wave sweeps by. If the ozone layer came back before now, it is again wiped away.

Flying Debris

Unfortunately, supernova blast waves have more than one danger zone. Starting about .5 to 1.0 light-year behind the spherical blast wave's front is a shell filled with all the radioactive dust, gas, and other debris previously swept up by the explosion, plus anything the exploding star itself threw out, all moving at relativistic (near-light) speeds. This material is called shocked ejecta, or simply ejecta. The dust should prove no problem for Earth dwellers thanks to the eroding effects of the atmosphere, though space travelers would find it instantly lethal.

The front of the shocked ejecta from van Maanen's Star should reach Earth about 20 years after the leading edge of the blast wave passes by, give or take a few years. An amazing display of micrometeors constantly illuminates the night sky during this period. (These figures are guesstimated from the above sources.) Cosmic ray levels in space drop a bit as the debris passes through, but Earth's atmosphere still takes a terrific hit and displays all signs of dysfunction described earlier.

It has been theorized that the blast wave will bring with it other forms of matter swept along since the star blew up, perhaps ice particles from the Sun's Oort cloud, or microscopic crystals of iron. (As this is outer space we're talking about, ice and hot gas can exist at the same time in almost the same place; in our Solar System, comets often fly past clouds of super-hot plasma ejected from the Sun.) Again, Earth's thick atmosphere will destroy all of this debris in short order. The arrival of objects large enough to create impact craters is extremely unlikely. The supernova blast wave is too diffuse to pulverize or hyper-accelerate anything smaller than a baseball, much less an asteroid, comet, or planet. Material the size of cosmic dust is often destroyed by contact with the blast wave if not swept up.

Reverse Shock

More bad news: behind this shell of fast-moving matter is the rear shockwave boundary, usually called the reverse shock. The reverse shock is also hot compared to surrounding space and generates immense amounts of x-rays and cosmic rays (which produce even more x-rays), but these cosmic rays are aimed backward, into the interior of the supernova remnant—and at anything the blast wave has left behind. In short, Earth is going to get it both coming and going.

The reverse shock reaches Earth about 80-90 years after the front shock does. Interplanetary cosmic-ray levels again skyrocket. The x-rays and cosmic rays once again wipe out any ozone present around Earth, bathing the land in undiluted solar UV-B until enough supernova smog is generated to prevent it. The double-slam of cosmic rays produces even more nitrogen oxides and other deadly compounds, more cloud cover, a higher albedo for Earth, and a resurgence of the current ice age (if such occurs). The renewed muon rain has a century in which to wreak havoc over every square centimeter of exposed Earth and below. The continued existence of life, unless secreted away far below ground or in ocean trenches, is debatable. It will likely not be life such as humans once knew it.

Earth's magnetosphere might turn aside or absorb some of the incoming radiation. It cannot block it all, however, and dangerous amounts will get through. One imagines auroras more brilliant and colorful than any ever seen, visible everywhere on Earth, would appear as cosmic rays and ionized gas flood the van Allen radiation belts and spill downward to the ionosphere. Another short-term disruption of surviving electromagnetic systems might also be created for as long as the Earth passes through the shell of the supernova's remnant. Cosmic rays and their byproducts that make it to the ground will again do enormous damage to electronics and computer parts, if any such exist.

 

 

 

 

Will humanity make it, or disappear like uncounted species before? The answer is in the hands of the author.

Good luck, and good writing.