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NASA's Chandra Adds to Black Hole Birth Announcement

For Release: November 17, 2011


RCW 86
Credit: Optical: DSS; Illustration: NASA/CXC/M.Weiss
Press Image and Caption

New details about the birth of a famous black hole that took place millions of years ago have been uncovered, thanks to a team of scientists who used data from NASA’s Chandra X-ray Observatory and radio, optical and other X-ray telescopes.

Over three decades ago, Stephen Hawking placed -- and eventually lost -- a bet against the existence of a black hole in Cygnus X-1. Today, astronomers are confident the Cygnus X-1 system contains a black hole, and with these latest studies they have remarkably precise values of its mass, spin, and distance from Earth. With these key pieces of information, the history of the black hole has been reconstructed.

"This new information gives us strong clues about how the black hole was born, what it weighed and how fast it was spinning," said author Mark Reid of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. "This is exciting because not much is known about the birth of black holes."

Reid led one of three papers -- all appearing in the November 10th issue of The Astrophysical Journal -- describing these new results on Cygnus X-1. The other papers were led by Jerome Orosz from San Diego State University and Lijun Gou, also from CfA.

Cygnus X-1 is a so-called stellar-mass black hole, a class of black holes that comes from the collapse of a massive star. The black hole is in close orbit with a massive, blue companion star.

Using X-ray data from Chandra, the Rossi X-ray Timing Explorer, and the Advanced Satellite for Cosmology and Astrophysics, a team of scientists was able to determine the spin of Cygnus X-1 with unprecedented accuracy, showing that the black hole is spinning at very close to its maximum rate. Its event horizon -- the point of no return for material falling towards a black hole -- is spinning around more than 800 times a second.

An independent study that compared the evolutionary history of the companion star with theoretical models indicates that the black hole was born some 6 million years ago. In this relatively short time (in astronomical terms), the black hole could not have pulled in enough gas to ramp up its spin very much. The implication is that Cygnus X-1 was likely born spinning very quickly.

Using optical observations of the companion star and its motion around its unseen companion, the team made the most precise determination ever for the mass of Cygnus X-1, of 14.8 times the mass of the Sun. It was likely to have been almost this massive at birth, because of lack of time for it to grow appreciably.

"We now know that Cygnus X-1 is one of the most massive stellar black holes in the Galaxy," said Orosz. "And, it's spinning as fast as any black hole we've ever seen."

Knowledge of the mass, spin and charge gives a complete description of a black hole, according to the so-called "No Hair" theorem. This theory postulates that all other information aside from these parameters is lost for eternity behind the event horizon. The charge for an astronomical black hole is expected to be almost zero, so only the mass and spin are needed.

"It is amazing to me that we have a complete description of this asteroid-sized object that is thousands of light years away," said Gou. "This means astronomers have a more complete understanding of this black hole than any other in our Galaxy."

The team also announced that they have made the most accurate distance estimate yet of Cygnus X-1 using the National Radio Observatory's Very Long Baseline Array (VLBA). The new distance is about 6,070 light years from Earth. This accurate distance was a crucial ingredient for making the precise mass and spin determinations.

The radio observations also measured the motion of Cygnus X-1 through space, and this was combined with its measured velocity to give the three-dimensional velocity and position of the black hole.

This work showed that Cygnus X-1 is moving very slowly with respect to the Milky Way, implying it did not receive a large "kick" at birth. This supports an earlier conjecture that Cygnus X-1 was not born in a supernova, but instead may have resulted from the dark collapse of a progenitor star without an explosion. The progenitor of Cygnus X-1 was likely an extremely massive star, which initially had a mass greater than about 100 times the sun before losing it in a vigorous stellar wind.

In 1974, soon after Cygnus X-1 became a good candidate for a black hole, Stephen Hawking placed a bet with fellow astrophysicist Kip Thorne, a professor of theoretical physics at the California Institute of Technology, that Cygnus X-1 did not contain a black hole. This was treated as an insurance policy by Hawking, who had done a lot of work on black holes and general relativity.

By 1990, however, much more work on Cygnus X-1 had strengthened the evidence for it being a black hole. With the help of family, nurses, and friends, Hawking broke into Thorne's office, found the framed bet, and conceded.

"For forty years, Cygnus X-1 has been the iconic example of a black hole. However, despite Hawking's concession, I have never been completely convinced that it really does contain a black hole -- until now," said Thorne. "The data and modeling described in these three papers at last provide a completely definitive description of this binary system."

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

For Chandra images, multimedia and related materials, visit:

For an additional interactive image, podcast, and video on the finding, visit:

Media contacts:
Janet Anderson
NASA Marshall Space Flight Center, Ala.

Megan Watzke
Chandra X-ray Center, Cambridge, Mass.

Visitor Comments (21)

I agree with Jay
It is astounding the amount of undiscovered knowledge lays across the multiverse.
Just looking at the map of Cygnus tonight made me think WOW. If those are all individual stars or planets. Imagine the possibilities of not only life but elements and functions we can only begin to fathom.

Posted by Kay on Tuesday, 02.27.18 @ 05:39am

Creative post - I Appreciate the facts. Does someone know where my assistant might be able to get a hold of a template Copyright Form VA form to type on?

Posted by teresa montano on Tuesday, 06.28.16 @ 05:56am

A note to John above who posted the distance. In the sort of notation that it is written in, perhaps it got confused. Cygnus X-1 is at a distance of six thousand and seventy light years, 6070.0ly. The picture frame is 424 x 530 ly in extent. They are really enormous numbers. And this is just in our galaxy.

Posted by Crano Blythe on Monday, 08.3.15 @ 22:31pm

I understand that although black holes are voracious in their local sphere, their field of gravitational influence is not a threat to distances such as that of our planet six thousand light years. However, if their jet were aimed in our direction, we might suffer from that.
Jim Carlisle

Posted by Jim Carlisle on Sunday, 01.18.15 @ 18:53pm

How far is the companion star from Cygnus X-1?

Posted by Gail MacVicar on Sunday, 10.20.13 @ 04:50am

Great! beyond compare

Posted by Dr Sunil Parashar on Monday, 08.26.13 @ 15:13pm

IF I could turn back the time or be reborn again I would become an Astrophysicist instead of an Engineer...All I could say is that Astrophysicist are lucky and I love them.

Posted by Geovani Luna on Saturday, 06.15.13 @ 00:48am

I love Cygnus X-1 picture! So fantasy...

Posted by Millinia Chelengga on Wednesday, 08.8.12 @ 05:06am

Wow. If one of those jets hit us it would cause global devastation and enormous solar flares. That a fact.

Posted by chris on Wednesday, 04.18.12 @ 09:46am

I had read that Cygnus X-1 ejected giant X-ray beams from it's poles.

And that these X-ray beams can shoot across the galaxy effecting other celestial bodies.

I wonder if these X-ray beams directed toward our sun can can cause solar flares?

Posted by Dan on Friday, 03.16.12 @ 10:54am

No point investing is anything else, but this vast expanse of knowledge and possibilities. Very humbling experience to view Chandra's images and the realities behind such heavenly bodies. We are insignificant in such a vast expanse of emptiness, but Chandra makes our existence significant.

My respects to Chandra and always ready to provide whatever help needed.

Posted by amar_almora on Saturday, 03.3.12 @ 04:05am

Wow keep up the good work what a great team of people you are to get these pitures

Posted by Anthony Barrett on Sunday, 12.18.11 @ 18:38pm

We know so less about it.Why we dont invest more in this kind of resarch....?
Seems we are more busy to destroy our planet which is so fagile!
I would like to know more about it

Posted by Lucian on Wednesday, 12.7.11 @ 01:22am

This info re black holes is terrific! Please write more on the black hole in center of our galaxy, & if it will affect the Sun....Mahalo! (Means thank you in Hawaiian), since I live here on the western flanks of Mauna Kea, near our largest & newest observatories.. on the great Big Island.

Posted by maji foster on Wednesday, 11.30.11 @ 17:08pm

Wow, thank you for sharing.

Posted by Debra Ramey on Wednesday, 11.30.11 @ 05:58am

makes one wonder doesn't it!?

Posted by ros on Tuesday, 11.29.11 @ 15:55pm

How far away is this? I know it is 60.070 light years away, but how far is that?

Posted by john on Tuesday, 11.29.11 @ 09:57am

I always wanted to be an astronomer, but became a doctor. Thank you for sharing this new development in the cosmos. Dale

Posted by Dale Calkin on Friday, 11.18.11 @ 17:58pm

Isn't this scary close to us?

Posted by Laurent Chauvin on Friday, 11.18.11 @ 17:06pm

wow!!! give me more like this.

Posted by alan soden on Friday, 11.18.11 @ 16:41pm

I am stunned by what we don't know and how little we know about universe

Posted by Jay on Friday, 11.18.11 @ 01:53am