Heaviest Stellar Black Hole Discovered in Nearby Galaxy

[ashish27]

<br />http://www.nasa.gov/mission_pages/chandra/news/07-112.html <br /><br /><br />Astronomers have located an exceptionally massive black hole in orbit around a huge companion star. This result has intriguing implications for the evolution and ultimate fate of massive stars. <br /><br />The black hole is part of a binary system in M33, a nearby galaxy about 3 million light years from Earth. By combining data from NASA’s Chandra X-ray Observatory and the Gemini telescope on Mauna Kea, Hawaii, the mass of the black hole, known as M33 X-7, was determined to be 15.7 times that of the Sun. This makes M33 X-7 the most massive stellar black hole known. A stellar black hole is formed from the collapse of the core of a massive star at the end of its life. <br /><br />"This discovery raises all sorts of questions about how such a big black hole could have been formed,†said Jerome Orosz of San Diego State University, lead author of the paper appearing in the October 18th issue of the journal Nature. <br /><br />M33 X-7 orbits a companion star that eclipses the black hole every three and a half days. The companion star also has an unusually large mass, 70 times that of the Sun. This makes it the most massive companion star in a binary system containing a black hole. <br /><br />"This is a huge star that is partnered with a huge black hole," said coauthor Jeffrey McClintock of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "Eventually, the companion will also go supernova and then we’ll have a pair of black holes." <br /><br />The properties of the M33 X-7 binary system – a massive black hole in a close orbit around a massive companion star – are difficult to explain using conventional models for the evolution of massive stars. The parent star for the black hole must have had a mass greater than the existing companion in order to have formed a black hole before the companion

 

[h2ouniverse]

looks like a future target for XEUS

 

[Kalstang]

This kinda brings up an interesting question. (at least for me..dont know if its been answered before.) What happens when 2 black holes occupy the same area? In other words what would happen if the star next to this black hole became a black hole? How would the two react with each other? <div class="Discussion_UserSignature"> <font color="#ffff00"><p><font color="#3366ff">I have an answer for everything...you may not like the answer or it may not satisfy your curiosity..but it will still be an answer.</font> <br /><font color="#ff0000">"Imagination is more important then Knowledge" ~Albert Einstien~</font> <br /><font color="#cc99ff">Guns dont kill people. People kill people</font>.</p></font><p><font color="#ff6600">Solar System</font></p> </div>

 

[doubletruncation]

It's an intersting question, but we don't have observational evidence to address it (there's no way for us to find binary black holes at present). Theoretically though they should emit gravitational radiation and spiral together until they coallesce into one big black hole emitting a burst of gravitational radiation in the process. Such events are among the primary things that gravitational radiation detectors are hoping to find. There's paper after paper predicting the rates of these things and the strength of the signal and whether or not detectors that people are working on will find them.<br /><br />It's also an interesting question as to what will happen when the other star goes supernova in the presence of the BH. If we're lucky (1 in a hundred thousand chance) the star will go supernova in the next few decades and we'll find out. <div class="Discussion_UserSignature"> </div>

 

[alokmohan]

Yes,right.But the biggest stellar block hole is only 15 solar mass .Figure appears too small.Check up?

 

[ashish27]

No the figures are okay, its a stellar black hole and not a supermassive one<br />http://en.wikipedia.org/wiki/Stellar_black_hole <br /><br />The story though inspires me to write science fiction. What would be life like if the 70 sol mass star has a habitable planet? What would be the religion of such a planet with a black hole so close by? I don't know why, but I find this story very stimulating.

 

[alokmohan]

Some days back I was readingof a star of 300 solar masses.I have to check up.Any way you are obsessed with habitable plat.I suggest you read astrobio/net.You may like it.Its on astrobiology.

 

[ashish27]

Of course im obsessed with habitable planets. So should you. Therein lies the far future of the human race

 

[pyoko]

Pardon my ignorance, but is 150 times the size of our Sun really that much? Including the fact that the subsequent black hole could have already sucked in a few gas giants and maybe an accretion disc?<br />Apart from the fact that we haven't seen this yet, does this actually break any former assumptions? <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>

 

[synical]

I was under the impression that if (or should I say 'when') a star goes supernova, regardless of it's size, it still expands into and enormous cloud of gas and dust and other not so exciting things, *before* it collapses into a black hole? <br /><br />If that is in fact the case, wouldn't it's binary cousin (the super heavy black hole) exert enough gravitational pull on the gas/dust cloud to significantly reduce it's mass therefore the mass of the exploded star and therefore it's ability to collapse into a black hole? <br /><br />Bear in mind that I'm totally new to astronomy so I'm most likely wrong =P

 

[CalliArcale]

Sort of. Stars expand and become much less dense in their outer layers as they move away from main sequence. As I understand it, this is a consequence of moving away from fusing hydrogen. (Betelgeuse, a red supergiant in the constellation Orion, is very large and very diffuse as stars go. I believe it is currently fusing helium.) With really massive stars, they eventually get to the point of attempting to fuse iron, and that is the point where it all breaks down. Fusion stops, which means the outward pressure of all the energy being produced by fusion stops, and gravity wins -- the star collapses. If it is sufficiently massive, the product will be a black hole.<br /><br />Binary cousins of supergiant stars most certainly can suck material away from them. This can be enough to prevent the giant from becoming a black hole; when the giant collapses in this case, it will become a neutron star. This phenomenon is what allowed astronomers to discover Cygnus X-1, the first confirmed black hole. It sucks material off of its companion, creating a very hot accretion disk that radiates x-rays. (You could say it's not just white-hot -- it's x-ray-hot.)<br /><br />Other stellar remnants can also do this. Neutron stars can suck material off of main-sequence or giant companions. As clumps of the material fall onto the surface of the neutron star, it explodes, producing (IIRC) a Type 1A supernova.<br /><br />(Note: I am a software engineer, not an astronomer or astrophysicist. I probably bungled this post, therefore.) <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[CalliArcale]

Ah, I looked up details on Wikipedia. Type IA supernovas generally result from infalling material on white dwarfs (not neutron stars). In the description of Type Ib and Ic supernovas, it gives this interesting information:<br /><br /><i>These events, like supernovae of Type II, are probably massive stars running out of fuel at their centers; however, the progenitors of Types Ib and Ic have lost most of their outer (hydrogen) envelopes due to strong stellar winds or else from interaction with a companion.[39] Type Ib supernovae are thought to be the result of the collapse of a massive Wolf-Rayet star. There is some evidence that a few percent of the Type Ic supernovae may be the progenitors of gamma ray bursts (GRB), though it is also believed that any hydrogen-stripped, Type Ib or Ic supernova could be a GRB, dependent upon the geometry of the explosion.[40]</i><br /><br />ref http://en.wikipedia.org/wiki/Supernova <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[alokmohan]

stronomers have located an exceptionally massive black hole in orbit around a huge companion star. This result has intriguing implications for the evolution and ultimate fate of massive stars.<br /><br />The black hole is part of a binary system in M33, a nearby galaxy about 3 million light years from Earth. By combining data from NASA's Chandra X-ray Observatory and the Gemini telescope on Mauna Kea, Hawaii, the mass of the black hole, known as M33 X-7, was determined to be 15.7 times that of the Sun. This makes M33 X-7 the most massive stellar black hole known. A stellar black hole is formed from the collapse of the core of a massive star at the end of its life.<br /><br />"This discovery raises all sorts of questions about how such a big black hole could have been formed," said Jerome Orosz of San Diego State University, lead author of the paper appearing in the October 18th issue of the journal Nature.<br /><br />M33 X-7 orbits a companion star that eclipses the black hole every three and a half days. The companion star also has an unusually large mass, 70 times that of the Sun. This makes it the most massive companion star in a binary system containing a black hole.<br /><br />"This is a huge star that is partnered with a huge black hole," said coauthor Jeffrey McClintock of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. "Eventually, the companion will also go supernova and then we'll have a pair of black holes."<br /><br />The properties of the M33 X-7 binary system — a massive black hole in a close orbit around a massive companion star — are difficult to explain using conventional models for the evolution of massive stars. The parent star for the black hole must have had a mass greater than the existing companion in order to have formed a black hole before the companion star.<br /><br />Such a massive star would have had a radius larger than the present separation between the stars, so the stars must have been brought closer while sharin

 

[alokmohan]

Odd Couples: Big black holes challenge star theory<br />Ron Cowen<br /><br />The most massive stars in the universe collapse to form black holes at the end of their lives. Theory suggests that such black holes can't have much more than about 10 times the sun's mass, but a team has now identified one that tips the scales at 15.65 times the sun's mass. Another research group has tentative evidence of an even bigger beast. <br /><br /><br /> <br />BIG HOLE. A star (blue object) about 70 times as massive as the sun orbits a black hole 15.65 times the sun's mass in the nearby galaxy M33 in this artist's depiction. A gas and dust disk (orange) encircles the black hole. Bright blue object (inset) in this composite X-ray and visible-light image is the orbiting stellar pair, known as M33 X-7.<br />M. Weiss, CXC, NASA; (Inset) Orosz et al., NASA, STScI<br /> <br /><br /><br />The findings may call into question current predictions about the evolution and ultimate fate of heavyweight stars. <br /><br />Jerome Orosz of San Diego State University and his colleagues studied a pair of closely orbiting stars in the nearby galaxy M33. As seen from Earth, each star periodically passes in front of the other, and the durations of these eclipses revealed that one of the partners must be extremely compact. From visible-light observations, the researchers determined that the other star has a mass 70 times that of the sun. Knowing that star's mass and orbit, they calculated that the compact partner weighs 15.65 solar masses. That would mean it must be a black hole—in fact, the heaviest stellar-mass black hole ever to be precisely measured, Orosz and his colleagues report in the Oct. 18 Nature. <br /><br />The pairing of such a black hole with a massive normal star "is very difficult to explain using stellar evolutionary models," the team asserts. The more massive a star, the <br />http://www.sciencenews.org/articles/20071027/fo

 

[MeteorWayne]

You never do actually read the threads before you post in them do you?<br />This is a duplicate of the opening post <img src="/images/icons/frown.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[alokmohan]

Opening post was from nasa.This one from science news.Is it same?

 

[MeteorWayne]

Yes.... <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[alokmohan]

But I hope for a bigger black hole .Why not 100 stellar mass ?What prevents?

 

[ashish27]

You got it. See my new thread on missing black holes

 

[alokmohan]

That Chandra my Indian turned American cousin?

 

[alokmohan]

Using two NASA satellites, astronomers have discovered a black hole that obliterates a record announced just two weeks ago. The new black hole, with a mass 24 to 33 times that of our Sun, is the heftiest known black hole that orbits another star. <br /><br />The record-breaker belongs to the category of "stellar-mass" black holes. Formed in the death throes of massive stars, they are smaller than the monster black holes found in galactic cores. The previous record holder for largest stellar-mass black hole is a 16-solar-mass black hole in the galaxy M33, announced on October 17. <br /><br />"We weren't expecting to find a stellar-mass black hole this massive," says Andrea Prestwich of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., lead author of the discovery paper in the November 1 Astrophysical Journal Letters. "We now know that black holes that form from dying stars can be much larger than http://www.spaceref.com/news/viewpr.nl.html?pid=23908<br />