[♪ INTRO]
If you spend any time studying space, you’re
bound to find some strange stuff;
that’s one of the best parts about astronomy.
But every now and then,
even the most experienced scientists
find something that makes them
scratch their heads.
Like Przybylski’s Star.
We’ve been studying it since the 1960s,
but we still can’t seem to figure out
what the thing is made of.
And according to one study, that might be
because it contains elements or isotopes
scientists have never seen before.
Move over, Tabby’s Star, because this might
be the weirdest star in the universe.
Przybylski’s Star is about
370 light-years away,
and it’s named after the Polish
astronomer who first studied it.
Przybylski published his first paper
about the object in 1961,
based on spectroscopy observations.
This is a common method that
links the type of light a star emits
to the elements it contains,
among other things.
And right away, he knew the observations of
this star weren’t normal.
For one, based on its spectrum, the star seemed
to have barely any iron in it, which was weird.
Most stars survive by fusing
lighter elements into heavier ones,
and iron is one of the most common results.
On the other hand, this star also seemed to
be chock full of lanthanides,
even heavier elements like holmium and europium,
which normally aren’t as abundant in stars.
At the time, Przybylski suggested this star
must be pretty far along in its lifespan
to have produced so many heavy elements.
But today, we know the story is a little more
complicated than that. Isn’t it always?
Thanks to lots of scientists and telescope hours,
we now know that Przybylski’s Star is actually part of a special class called
Ap stars, or A-type peculiar stars.
Regular A-type stars are usually
hot and have no magnetic fields.
But Ap stars have cool surfaces, strong magnetic
fields, and really long rotation periods.
For some reason, these stars also tend to
have lots of lanthanides, but not much iron.
So in that respect, Przybylski’s Star isn’t
as odd as we first thought.
But that doesn’t mean it’s normal, either.
According to a few papers,
there’s evidence that this star
also contains atoms that have
no business being there at all.
Specifically, ones like promethium and plutonium.
These elements and their isotopes, or versions
with a different number of neutrons,
have relatively short half-lives.
This is the time it takes for half of the
atoms in a radioactive substance
to decay into something else.
Promethium, for example, has a
half-life of less than 20 years.
And plutonium has a half-life of
some 24,000 years at most,
which is still barely any time
at all for a star.
That means that, unless they’re new additions
or are being replenished somehow,
they should have all completely decayed by the
time humans and telescopes showed up.
So far, there are a few possible
explanations for this.
Some astronomers have suggested that these
atoms could have come from a recent supernova,
or from ongoing reactions catalyzed
by a nearby neutron star.
But the evidence for these ideas
isn’t that strong.
You also can’t have an astronomy mystery
without some alien hypotheses.
But, uh, if you have any peer-reviewed papers
about that, you can let us know.
Still, there’s one other possible explanation
that doesn’t involve First Contact.
And if it’s true, it would change the textbooks,
and not just the astronomy ones.
In 2017, in the journal Physical Review A,
three researchers suggested that
Przybylski’s Star might actually contain
super heavy elements or isotopes
we haven’t even discovered yet.
And, over time, these super heavy atoms could
decay into the short-lived isotopes we’ve observed.
Specifically, they proposed that the atoms
could be versions of three elements:
flerovium, unbihexium, or unbinilium.
We’ve made really tiny quantities
of flerovium in the lab before,
like, around 100 atoms total,
but we’ve never seen it in nature.
And although we think unbihexium and unbinilium
should exist based on what we know about chemistry,
we haven’t observed them yet.
So if this hypothesis is true, it would
mean that studying Przybylski’s Star
would let us see these atoms in the wild,
or at all, for the first time!
There’s even a chance that the isotopes
in the star would be part of the
island of stability, a hypothetical group
of heavy, extra stable elements
that scientists have been trying to track down.
That would make this star
not only important for astronomy,
but for chemistry and physics on Earth, too.
Now, it is worth mentioning that the team
didn’t have any new explanation for how
those heavy atoms would’ve gotten there.
And there’s still a chance we misread
the data, and that Przybylski’s Star
doesn’t really contain short-lived isotopes.
After all, the spectrum for this star, like
the one Przybylski first used to study it,
is difficult to read.
Normally, spectra have a few fairly clear-cut
lines that scientists can link to different elements.
But for this star, those lines are
kind of all over the place.
So there’s an ongoing debate about what’s
going on, because something weird is
definitely happening to produce
that messy spectrum.
One helpful next step would be to take more
measurements and hope they’re clearer.
But there’s a lot of other stuff to study,
too, so most people aren’t actively looking into it.
In the meantime, researchers will keep trying
to solve this mystery with what they have.
And maybe one day, they’ll get to name some
new elements because of it.
Thanks for watching this episode
of SciShow Space!
If you’d like to learn more about how stars
have transformed the universe,
you can watch our episode
about the very first stars.
Because without their influence,
you wouldn’t be here.
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