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Astronomy Picture for Today
nasa ^
| 07/31/2006
| dg
Posted on 07/31/2006 1:03:10 PM PDT by HOTTIEBOY
At the Center of the Milky Way
Credit: Rainer Schödel (MPE) et al., NAOS-CONICA, ESO
At the center of our Milky Way Galaxy lies a black hole with over 2 million times the mass of the Sun. Once a controversial claim, this astounding conclusion is now virtually inescapable and based on observations of stars orbiting very near the galactic center. Using one of the Paranal Observatory's very large telescopes and the sophisticated infrared camera NACO, astronomers patiently followed the orbit of a particular star, designated S2, as it came within about 17 light-hours of the center of the Milky Way (17 light-hours is only about 3 times the radius of Pluto's orbit). Their results convincingly show that S2 is moving under the influence of the enormous gravity of an unseen object which must be extremely compact -- a supermassive black hole. This deep NACO near-infrared image shows the crowded inner 2 light-years of the Milky Way with the exact position of the galactic center indicated by arrows. NACO's ability to track stars so close to the galactic center can accurately measure the black hole's mass and perhaps even provide an unprecedented test of Einstein's theory of gravity as astronomers watch a star orbit a supermassive black hole.
The Swarm
Credit: M. P. Muno (UCLA) et al., CXC, NASA
What do you call a group of black holes ... a flock, a brace, a swarm? Monitoring a region around the center of our Galaxy, astronomers have indeed found evidence for a surprisingly large number of variable x-ray sources - likely black holes or neutron stars in binary star systems - swarming around the Milky Way's own central supermassive black hole. Chandra Observatory combined x-ray image data from their monitoring program is shown above, with four variable sources circled and labeled A-D. While four sources may not make a swarm, these all lie within only three light-years of the central supermassive black hole known as Sgr A* (the bright source just above C). Their detection implies that a much larger concentration of black hole systems is present. Repeated gravitational interactions with other stars are thought to cause the black hole systems to spiral inward toward the Galactic Center region.
TOPICS: Astronomy; Astronomy Picture of the Day; Science
KEYWORDS: asstronomy; space
1
posted on
07/31/2006 1:03:10 PM PDT
by
HOTTIEBOY
To: KevinDavis; fnord; Michael Goldsberry; rdb3; MNJohnnie; thoughtomator; Woman on Caroline Street; ...
PING
2
posted on
07/31/2006 1:06:09 PM PDT
by
HOTTIEBOY
(I'm your huckleberry)
To: HOTTIEBOY
3
posted on
07/31/2006 1:06:52 PM PDT
by
Darkwolf377
(http://www.dansimmons.com/news/message/2006_04.htm)
To: Darkwolf377
YOU ARE HERE Or the more Zen notion "ARE YOU HERE?"
To: HOTTIEBOY
What do you call a group of black holes ... ? A swisserie?
5
posted on
07/31/2006 1:25:36 PM PDT
by
theDentist
(Qwerty ergo typo : I type, therefore I misspelll.)
To: theDentist
What do you call a group of black holes ... ? A swisserie?
A harem????
6
posted on
07/31/2006 1:30:20 PM PDT
by
The_Victor
(If all I want is a warm feeling, I should just wet my pants.)
To: HOTTIEBOY
What do you call a group of black holes A posse.
7
posted on
07/31/2006 1:33:32 PM PDT
by
dead
(I've got my eye out for Mullah Omar.)
To: Darkwolf377
Everybody has to be somewhere, it might as well be here. If I was over there then there would be here and here would be there and who's on first?
8
posted on
07/31/2006 3:40:30 PM PDT
by
Tiny
To: HOTTIEBOY
Uhh...E.T. can you hear me now...I got a new cell phone.
9
posted on
08/01/2006 1:24:02 PM PDT
by
ihv2bme
(Do things not until you get it right, but until you can't get it wrong!)
To: ihv2bme
CAN YA HEAR ME NOW...GOOD!!......JJ61
10
posted on
11/11/2006 9:27:44 PM PST
by
JerseyJohn61
(Better Late Than Never.......sometimes over lapping is worth the effort....)
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