Cidersomerset
17th July 2013, 13:43
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17 July 2013 Last updated at 12:00
Black hole-bound gas cloud 'stretched like spaghetti'Gas cloud The gas cloud is being
stretched out by the gravity of our galaxy's central black hole
http://news.bbcimg.co.uk/media/images/68782000/jpg/_68782354_68782353.jpg
The giant gas cloud heading for the black hole at the centre of our galaxy has begun its
death spiral.The cloud, known as G2 is now being stretched out like a piece of spaghetti
by the black hole's extreme gravity.This gravitational field has caused the head of the
cloud to accelerate around the black hole and to speed back towards us.Astronomers
have been closely observing G2, hoping to catch it being ripped apart and eaten by the
black hole.Details of the latest observations are outlined in the Astrophysical Journal.
Could you survive falling into one?
The cloud of gas - three times larger than Pluto's orbit but with a total mass just three
times that of the Earth - was first spotted on its course toward the galaxy's centre in
2011. The mass of the black hole at the centre of the Milky Way is estimated to be four
million times that of the Sun and is formally known as Sagittarius A (Sgr A*). It is the
closest known "supermassive" black hole and is therefore considered the best places to
study these dense objects in detail.
"The most exciting thing we now see in the new observations is the head of the cloud
coming back towards us at more than 10 million km/h along the orbit - about 1% of the
speed of light," said Reinhard Genzel, from the Max Planck Institute for Extraterrestrial
Physics in Germany.
"This means that the front end of the cloud has already made its closest approach to the
black hole."
The origin of the gas cloud remains unclear, although a variety of ideas have been
proposed. These range from its recent formation due to a collision between stellar winds
and the interstellar medium to its origins as a jet emerging from the galactic centre to a
faint star that is losing increasing amounts of gas.G2 gas cloud
http://news.bbcimg.co.uk/media/images/68785000/jpg/_68785535_68785533.jpg
The head of the cloud is now travelling much faster than the tail
The new observations argue against the cloud possessing a stellar core that would
constantly be supplying new gas."We see that the cloud is now being stretched so much
that it resembles spaghetti. This means that it probably doesn't have a star in it," said
Stefan Gillessen, also from the Max Planck Institute, who has been leading the
observing team."At the moment we think that the gas probably came from the stars we
see orbiting the black hole."Due to the tidal forces stretching G2, the front of the cloud
is now moving about 500 km/s faster than its tail.
The astronomers have been using the Very Large Telescope (VLT) in Chile to study G2.
As the gas cloud is stretched its light gets harder to see. But by staring at the region
close to the black hole for more than 20 hours of total exposure time with the VLT's
Sinfoni instrument, the team was able to measure the velocities of different parts of the
cloud as it streaked past the central black hole.
http://www.bbc.co.uk/news/science-environment-23343563
17 July 2013 Last updated at 12:00
Black hole-bound gas cloud 'stretched like spaghetti'Gas cloud The gas cloud is being
stretched out by the gravity of our galaxy's central black hole
http://news.bbcimg.co.uk/media/images/68782000/jpg/_68782354_68782353.jpg
The giant gas cloud heading for the black hole at the centre of our galaxy has begun its
death spiral.The cloud, known as G2 is now being stretched out like a piece of spaghetti
by the black hole's extreme gravity.This gravitational field has caused the head of the
cloud to accelerate around the black hole and to speed back towards us.Astronomers
have been closely observing G2, hoping to catch it being ripped apart and eaten by the
black hole.Details of the latest observations are outlined in the Astrophysical Journal.
Could you survive falling into one?
The cloud of gas - three times larger than Pluto's orbit but with a total mass just three
times that of the Earth - was first spotted on its course toward the galaxy's centre in
2011. The mass of the black hole at the centre of the Milky Way is estimated to be four
million times that of the Sun and is formally known as Sagittarius A (Sgr A*). It is the
closest known "supermassive" black hole and is therefore considered the best places to
study these dense objects in detail.
"The most exciting thing we now see in the new observations is the head of the cloud
coming back towards us at more than 10 million km/h along the orbit - about 1% of the
speed of light," said Reinhard Genzel, from the Max Planck Institute for Extraterrestrial
Physics in Germany.
"This means that the front end of the cloud has already made its closest approach to the
black hole."
The origin of the gas cloud remains unclear, although a variety of ideas have been
proposed. These range from its recent formation due to a collision between stellar winds
and the interstellar medium to its origins as a jet emerging from the galactic centre to a
faint star that is losing increasing amounts of gas.G2 gas cloud
http://news.bbcimg.co.uk/media/images/68785000/jpg/_68785535_68785533.jpg
The head of the cloud is now travelling much faster than the tail
The new observations argue against the cloud possessing a stellar core that would
constantly be supplying new gas."We see that the cloud is now being stretched so much
that it resembles spaghetti. This means that it probably doesn't have a star in it," said
Stefan Gillessen, also from the Max Planck Institute, who has been leading the
observing team."At the moment we think that the gas probably came from the stars we
see orbiting the black hole."Due to the tidal forces stretching G2, the front of the cloud
is now moving about 500 km/s faster than its tail.
The astronomers have been using the Very Large Telescope (VLT) in Chile to study G2.
As the gas cloud is stretched its light gets harder to see. But by staring at the region
close to the black hole for more than 20 hours of total exposure time with the VLT's
Sinfoni instrument, the team was able to measure the velocities of different parts of the
cloud as it streaked past the central black hole.
http://www.bbc.co.uk/news/science-environment-23343563