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NASA's Chandra Suggests Rare Explosion Created Our Galaxy's Youngest Black Hole

For Release: February 13, 2013


PKS 0745
Credit: X-ray: NASA/CXC/MIT/L.Lopez et al.; Infrared: Palomar; Radio: NSF/NRAO/VLA
Press Image and Caption

WASHINGTON -- New data from NASA's Chandra X-ray Observatory suggest a highly distorted supernova remnant may contain the most recent black hole formed in the Milky Way galaxy. The remnant appears to be the product of a rare explosion in which matter is ejected at high speeds along the poles of a rotating star.

The remnant, called W49B, is about a thousand years old as seen from Earth and located about 26,000 light-years away.

"W49B is the first of its kind to be discovered in the galaxy," said Laura Lopez, who led the study at the Massachusetts Institute of Technology. "It appears its parent star ended its life in a way that most others don't."

Usually when a massive star runs out of fuel, the central region of the star collapses, triggering a chain of events that quickly culminate in a supernova explosion. Most of these explosions are generally symmetrical, with the stellar material blasting away more or less evenly in all directions.

However, in the W49B supernova, material near the poles of the doomed rotating star was ejected at a much higher speed than material emanating from its equator. Jets shooting away from the star's poles mainly shaped the supernova explosion and its aftermath.

The remnant now glows brightly in X-rays and other wavelengths, offering the evidence for a peculiar explosion. By tracing the distribution and amounts of different elements in the stellar debris field, researchers were able to compare the Chandra data to theoretical models of how a star explodes. For example, they found iron in only half of the remnant while other elements such as sulfur and silicon were spread throughout. This matches predictions for an asymmetric explosion.

"In addition to its unusual signature of elements, W49B also is much more elongated and elliptical than most other remnants," said co-author Enrico Ramirez-Ruiz of the University of California at Santa Cruz. "This is seen in X-rays and several other wavelengths and points to an unusual demise for this star."

Because supernova explosions are not well understood, astronomers want to study extreme cases like the one that produced W49B. The relative proximity of W49B also makes it extremely useful for detailed study.

The authors examined what sort of compact object the supernova explosion left behind. Most of the time, massive stars that collapse into supernovas leave a dense, spinning core called a neutron star. Astronomers often can detect neutron stars through their X-ray or radio pulses, although sometimes an X-ray source is seen without pulsations. A careful search of the Chandra data revealed no evidence for a neutron star. The lack of such evidence implies a black hole may have formed.

"It's a bit circumstantial, but we have intriguing evidence the W49B supernova also created a black hole," said co-author Daniel Castro, also of MIT. "If that is the case, we have a rare opportunity to study a supernova responsible for creating a young black hole."

Supernova explosions driven by jets like the one in W49B have been linked to gamma-ray bursts (GRBs) in other objects. GRBs, which have been seen only in distant galaxies, also are thought to mark the birth of a black hole. There is no evidence the W49B supernova produced a GRB, but it may have properties – including being jet-driven and possibly forming a black – that overlap with those of a GRB.

The new results on W49B, which were based on about two-and-a-half days of Chandra observing time, appear in a paper in Sunday's issue of the Astrophysical Journal. The other co-author was Sarah Pearson from the University of Copenhagen in Denmark.

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:
J.D. Harrington
Headquarters, Washington

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

Visitor Comments (20)

Harvard showing us the stars.

Posted by Alumni on Saturday, 04.22.17 @ 17:34pm

Very very cool. Much information about the stars.

Posted by Beevus on Tuesday, 05.24.16 @ 13:03pm

Repulsive reaction is more in W49B supernova by possibility of reversal in magnetic poles in any star
Material near the poles of the doomed rotating star was ejected at a much higher speed than material emanating from its equator. Jets shooting away from the star's poles mainly shaped the supernova explosion and its aftermath. W49B also is much more elongated and elliptical than most other remnants, Most of the time, massive stars that collapse into supernovas leave a dense, spinning core called a neutron star.

Posted by Sankaravelayudhan Nandakumar on Thursday, 01.15.15 @ 22:48pm

How did astronomers arrive at a date of the visual flare around 1,000 years ago? The Chinese recorded the nova responsible for the Crab Nebular in Taurus 1045 A.D. This supernova would have been far brighter. And yet, the Chinese do not appear to have recorded any such object in this time frame.

Posted by Gordon Brown on Monday, 12.1.14 @ 19:10pm

Thanks for the information.

Posted by jose on Wednesday, 05.7.14 @ 12:38pm

It's odd that the stars emit infrared light but not radio waves. We usually think of these wavelengths as being long and pretty much identical.

Posted by Gabriel on Wednesday, 03.12.14 @ 21:52pm

It's funny that the stars emit infrared light, but not radio waves. We usually think that both of these wavelengths are just short and aren't very different from each another

Posted by Gabriel on Wednesday, 03.12.14 @ 21:51pm

Very interesting. Quite the intriguer in the sense of astronomy.

Posted by Aditya on Sunday, 02.2.14 @ 13:49pm

This magnificent images only confirms that the Universe is in me... Woooaw!!

Posted by Margarita on Wednesday, 09.25.13 @ 16:42pm

It is wonderful.

Posted by abhisek das on Tuesday, 05.21.13 @ 14:02pm

Formation of black hole at the expense of sudden radiation and then the dimness subsequently controlled by monopoles to dual poles as the case may be.

Posted by Sankaravelayudhan Nandakumar on Tuesday, 05.21.13 @ 05:14am

This is actually very cool. Knowing of what scientist can find out, amazing! That is why I am going to be taking astronomy in college.

Posted by Laura on Friday, 05.10.13 @ 00:00am


Posted by david on Friday, 04.19.13 @ 11:28am

This is so great. I would love to go into space one day and see these wonderful images in real life. They are so cool.

Posted by hannah hope on Tuesday, 04.16.13 @ 14:25pm

This is amazing! It is also at the same time scary, because if we recently discovered a black hole a thousand years after it was formed. One could form and in danger earth and we wouldn't even realize it for centuries! But still... That is probably not going to happen. It is just so cool how black holes form and how they are such a mystery to man kind.

Posted by Sam on Saturday, 04.13.13 @ 22:38pm

Vary cool, it is nice.

Posted by Megan on Thursday, 04.4.13 @ 14:00pm

Very nice.

Posted by sachin on Monday, 03.25.13 @ 06:50am

Absolutely wonderful images on this site which I visit often. Thank you for the many wonderful photographs I have been able to download and print out.
I am fascinated by everything that occurs in this wonderful universe that we live. Without sites like Chandra, Hubble and NASA, none of this well explained information would be so readily available in the UK. Thanks to you all

Posted by Simone Williamson on Saturday, 03.23.13 @ 08:13am

Thank you for sending me information on the most recently formed black hole in our galaxy, W49B! Please send any other photos of this supernova remnant and any confirmation information. Kudos to L.Lopez and all others involved in the observation of W49B!

Billie Jean Gergis

Posted by Billie Jean Gergis on Friday, 03.15.13 @ 12:30pm

Man, these stars are so starry! I never thought that stars could look so real until I saw them. It makes me amazed to see stars. Bye!

Posted by Nicholas on Tuesday, 03.12.13 @ 13:04pm