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Астронет: Астрономическая картинка дня Взлет и падение сверхновой 2015F http://variable-stars.ru/db/msg/1355966/eng |
Credit & Copyright: Changsu Choi & Myungshin Im
(Seoul National University)
Explanation:
Sit back and watch a star explode.
The actual supernova occurred back when
dinosaurs roamed the Earth,
but images of the spectacular event began arriving last year.
Supernova 2015F was discovered in nearby spiral galaxy
NGC 2442 by
Berto Monard
in 2015 March and was unusually bright -- enough to be seen with only a small telescope.
The pattern of brightness variation indicated a
Type Ia supernova --
a type of stellar explosion that results when an Earth-size
white dwarf
gains so much mass that its core crosses the threshold of
nuclear fusion,
possibly caused by a lower mass
white-dwarf companion spiraling into it.
Finding and tracking Type Ia
supernovae are particularly important because their intrinsic brightness can
be calibrated,
making their
apparent brightness
a good measure of their distance -- and hence useful toward calibrating the
distance scale of the
entire universe.
The featured video tracked
the
stellar disruption
from before explosion images arrived, as it brightened,
and for several months as the
fission-powered supernova glow faded.
The remnants of
SN2015F are now too dim
to see without a large telescope.
Just yesterday, however, the night sky lit up
once again, this time
with an
even brighter supernova
in an even closer galaxy:
Centaurus A.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.