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Астронет: Астрономическая картинка дня Около черной дыры http://variable-stars.ru/db/msg/1305270/eng |
Credit & Copyright: April Hobart,
CXC
Explanation:
In the center of a swirling whirlpool of hot gas
is likely a beast that has never been seen directly: a
black hole.
Studies of the bright light emitted by the
swirling gas frequently indicate not only that a
black hole is present, but also likely attributes.
The gas surrounding GRO J1655-40, for example, has been found to display an unusual flickering
at a rate of 450 times a second.
Given a
previous mass estimate for the
central object of seven times the mass of our
Sun, the rate of the
fast flickering can be
explained by a black hole
that is rotating very rapidly.
What physical mechanisms actually cause the flickering -- and a slower quasi-periodic
oscillation (QPO) -- in
accretion disks surrounding
black holes and
neutron stars remains a topic of much research.
Find that image:
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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.