Stars that Mysteriously Disappear

Stars that Mysteriously Disappear


Stars eventually die. It’s a fact of the universe that they exhaust
their fuel in one way or another and eventually die. Some of them, giant stars, might only live
for a few million years before exploding as supernovae. Others, such as fuel efficient red dwarfs,
might lives enormously long lives and last as much as trillions of years. Still others, like our own sun, will go through
stages in life, first the sun we see now will change its equilibrium and transform itself
billions of years from now into a red giant, and likely swallow up the earth in the process. And then past that, it will become a cooling
white dwarf, more of a stellar cinder than a star. But there is a lot of predictability here. We know what classes of star will do what,
and what will very likely happen to them in the future through the study of stellar physics. But one thing stars generally don’t do is
just up and disappear. And even if there was a ready mechanism for
that to happen, they shouldn’t do it on scales of just a few years, other than perhaps
a certain type of rare supernova, more on that in a bit. And, there are candidates for stars that have
apparently simply disappeared for no apparent reason at all. The story goes back to a 2016 paper by Beatriz
Villarroel and colleagues, link in the description below, where they detail that by studying
past sky surveys in detail, things that might appear to be physically impossible, such as
the rapid disappearance of a star, might be spotted over time. Using several surveys, they spotted one object
that was of particular interest. It may or may not have disappeared right before
the eyes of our surveys. Fast forward to now. Villaroel and colleagues have released a new
paper, link below, covering what’s happened since 2016 in their work. In regards to the object of interest, it’s
uncertain what happened there, and further work shows that it may not have disappeared
at all. Instead, the object seems to still be there,
or an object close to its location but is now significantly dimmer than what was seen
in past sky surveys. If it’s a star, it dimmed. Now the reasonable question to ask here is
could the star simply be a variable star. The universe is full of stars that vary in
brightness, and currently the prominent night sky star Betelgeuse in Orion is at an unusual
low, prompting some to wonder if its about to go supernova, though that is highly unlikely. It’ll go sometime soon in geologic time,
but probably not tomorrow. Another option is a red dwarf that happened
to be flaring right when the sky survey that first detected it happened to be looking,
and it has since calmed down. Not a bad option at first look since we know
that some red dwarfs, particularly younger ones, can produce ridiculous flares that cause
them to brighten briefly, and therein perhaps sterilize some poor exoplanet that might be
developing life. But there are problems with that idea. If it was a flare, it was stronger than anything
thus far recorded. And it doesn’t really fit the profile of
a variable star either (FC). Could other causes be involved? Is it possible that a distant quasar be the
cause, and the data isn’t clearly showing what it is? Only more data and study will tell. But the idea of something changing in a manner
not easily explained in the galaxy is, of course, intriguing, especially over short
terms such as in these papers, even though the vast majority of detections of this sort
of thing will very likely end up having natural explanations. The paper goes on to detail that since 2016,
about 100 additional candidates have been found for inexplicably disappearing stars. And while the explanation is probably something
astrophysical, there’s a chance that it might also be a technosignature from an alien
civilization. But it’s best not to jump to conclusions
there. Also in 2016, the star KIC 8462852 was seen
to be dimming in a strange way, and was also undergoing a long term dimming trend that
might eventually make it appear to eventually disappear. While an alien origin for whatever was happening
at that star initially on the table because no one at the time had thought of a good natural
explanation, it’s since been found that very fine, smoke-like dust seems to be the
culprit in causing the dimming seen at this star, though just what the exact circumstances
of this are is still an open question though a new hypothesis suggests that it may actually
be a shredded exomoon. It pays to remember through this that there
are corners of astronomy that we do not yet completely understand. One example of this that may be relevant to
this mystery is the concept of failed supernovae. Essentially, what happens here is that a star
of a certain mass and size attempts to explode in a supernova event as it collapses into
a new life as a black hole. But it happens such that the explosion doesn’t
actually happen, rather the star essentially contains the explosion and draws it in, thus
preventing the supernova and simply producing a black hole directly from a collapsing star. These papers remind me of another oddball
instance in the history of astronomy. The mysterious disappearing stellar debris
disk. I’ve covered this on this channel before,
but I do so again because it almost seems like one of those mysteries of astronomy that
was forgotten and not really ever looked into much again. The star is called TYC 8241 2652 and it, at
first glance, appeared completely normal. The star was first observed in infrared in
1983 by NASA’s IRAS satellite. It was found to be young, and with a debris
disk of dust glowing brightly in infrared. As it should, protoplanetary disks like this
around young stars are not unusual, by any means. Our own solar system once looked much like
this while the planets were still forming. Fast forward to 2010. NASA’s WISE spacecraft observed the star and
all of that material was apparently gone, over just a few years, which was confirmed
a few years later with a ground telescope. The protoplanetary disk has just disappeared. It should take geologic time scales to clear
a disk like this, yet this star system did it within less than a human lifetime. How did that happen? There are no particularly good explanations
for this one. Perhaps something caused the debris disk to
fall into the star very rapidly. Or some cascade caused all the dust to crush
into smaller undetectable particles. But those aren’t very good explanations
and to this day no one knows what really happened at TYC 8241 2652. I think with the research going on that’s
going to get almost real time, short term events seen in the universe like these will
only grow the list of mysteries. And who knows, some day a candidate may come
along that has no good natural explanation and we are left with only one option. That what we see is an alien civilization. Thanks for listening! I am futurist and science fiction author John
Michael Godier currently noting that things around me tend to disappear. This ranges from my glasses, the phone, various
socks, and even pastries when ANNA does the health week inventory. The latter might be subterfuge on my part,
but I’m sure I’m not alone in misplacing things. It would not be pleasant if we woke up one
day and we managed to misplace the sun. What would the aliens think? First SETI message would be “What did you
do with your sun?” and we’d be like “Dunno, but getting cold around here”, not a pleasant
end and be sure to check out my books at your favorite online book retailer and subscribe
to my channels for regular, in-depth explorations into the interesting, weird and unknown aspects
of this amazing universe in which we live.

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