- 3982 - SUPERNOVAE - when are they dangerous? Supernovae superflares may be accompanied by enormous eruptions of charged particles that could devastate life on any planets in their firing line.
------------ 3982 - SUPERNOVAE - when are they dangerous?
- Scientists
scoping out a star system in the constellation Orion have witnessed one of the
most gargantuan and powerful stellar flares ever seen. This argantuan 'superflare' from a distant
star has launched one of the strongest solar storms ever seen.
-
- This
"superflare," was an enormous blast of stellar radiation 10 times
more massive than anything ever witnessed erupting from the sun. While the
mechanism behind this monster flare still isn't well understood, the new
research suggests that superflares originate from stars that are highly
magnetically active.
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- In this new
research, the astronomers targeted a star system called “V1355 Orionis”, which
is about 400 light-years from Earth and features two stars orbiting each other.
These stars belong to a class of stars known to harbor many sunspots, dark,
planet-size regions that form as the result of intense electromagnetic
activity, and that have been tied to other observed superflares.
-
- Stellar
flares occur when magnetic-field lines in a star's atmosphere tangle, snap and
reconnect, releasing a powerful gout of radiation that's visible across the
entire electromagnetic spectrum.
-
- On the sun,
flares may be accompanied by towering loops of plasma, known as prominences,
that can rise tens of thousands of miles above the sun's surface. If this solar
plasma launches quickly enough, it can break free of the sun and become a
coronal mass ejection (CME) which is an enormous blob of high-energy particles
that can knock satellites out of orbit and short-circuit power grids on Earth,
if our planet happens to be in the blob's path.
-
- Combining
observations from the “Transiting Exoplanet Survey Satellite” and the “Seimei
Telescope” in Japan, the researchers studied the distant star system in
multiple wavelengths of light to capture the most complete picture possible of
the superflare's evolution.
-
- They found
that the flare began with one of the most powerful stellar eruptions ever seen,
a high-velocity prominence that burst out of one of the stars at more than 2.2
million mph . This blast far exceeded the star's escape velocity, launching
trillions of tons of electrically charged matter outward into space in what may
be one of the largest CMEs ever observed.
-
- This
mega-flare's discovery is less a cautionary tale for our planet than it is a
caveat in the search for life on other worlds.
Planets around magnetically hyper star systems like V1355 Orionis may
not be the best places to look.
-
- Another
example of a dangerous place is a supermassive black hole that ripped a star to
shreds in the center of the galaxy NGC 7392. The flash of light from the black
hole's dinner finally reached Earth in 2014, and astronomers just discovered it
in their data.
-
- This newly
detected outburst is the closest-yet example of a “tidal disruption event”
(TDE), where a star is pulled apart by the massive gravitational pull of a
black hole.
-
- This black
hole was spotted 137 million light-years from Earth, or about 35 million times
as far as Proxima Centauri, the closest star to the sun. As distant as that
sounds, astronomers have only observed around 100 of these events so far, and
this one is four times closer than the previous title-holder of "closest
TDE to Earth”.
-
- They
discovered the TDE in infrared, a different wavelength than most conventional
TDE detections, which usually come in X-rays, ultraviolet, and optical light.
-
- Finding
this nearby TDE means that, statistically, there must be a large population of
these events that traditional methods were blind to. astronomers should try to find these in
infrared if we want a complete picture of black holes and their host galaxies.
-
- Previously
discovered TDEs mostly appeared in so-called green galaxies, which don’t create
quite as many stars as the more active blue galaxies but aren't totally
burned-out on star-making like red galaxies.
-
- NGC 7392,
however, is a blue galaxy churning out many new stars and creating a lot of
dust in the process. This dust could obscure the center of the galaxy, where
the supermassive black hole lives, in optical and ultraviolet light. But
infrared light enables astronomers to peer through that dust.
-
- Using
infrared surveys to catch the dust echo of obscured TDEs has already shown us
that there is a population of TDEs in dusty, star-forming galaxies that we have
been missing.
-
- By looking
for TDEs in infrared scientists could
get one step closer to understanding how black holes chow down on stars.
-
May 4, 2023 SUPERNOVAE - when
are they dangerous? 3982
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--------------------- --- Thursday, May 4, 2023
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