STEVE INSKEEP, Host:
NPR's Richard Harris says the story started in the backyard in Western Maryland.
RICHARD HARRIS: On the evening of April 15th, 1979, while countless Americans were rushing to finish their tax returns, Gus Johnson was on a cosmic pursuit in his backyard, touring one little corner of the heavens.
GUS JOHNSON: And I decided to share the tour using my eight-inch telescope and the pastor of my church.
HARRIS: The two men gazed up at a galaxy called M100 in the constellation Coma Berenices.
JOHNSON: For some reason, I don't know why, this little star in M100 caught my attention.
HARRIS: On a hunch, he pulled up a detailed chart of all the stars in this part of the sky.
JOHNSON: And it wasn't on it.
HARRIS: And Abraham Loeb at the Harvard Smithsonian Center for Astrophysics says when a star that size explodes, it can end up in one of two forms.
ABRAHAM LOEB: Either it makes a neutron star, which is the densest form of matter that we know about. It has the density similar to that of an atomic nucleus and a size comparable to that of a big city, or it ends up in a black hole, which is an object to which you can get in, but can never get out of.
HARRIS: So fast-forward to today. To figure out what befell the 1979 supernova, Loeb and his colleagues turned NASA's Chandra X-ray Observatory to that corner of the sky. And they now conclude that the supernova most likely ended up as a black hole.
LOEB: If our interpretation is correct - and indeed, Supernova 1979C ended up as a black hole - then, of course, it's the first time that we are seeing a black hole being born in a normal supernova.
HARRIS: Alex Filippenko from UC-Berkeley says in that event, X-rays they witness could be coming from a huge cloud of glowing gas called a pulsar wind nebula, like the picturesque crab nebula.
ALEX FILIPPENKO: So, I'm pretty excited about this discovery, regardless of whether it turns out to be a young black hole or a pulsar wind nebula.
HARRIS: Richard Harris, NPR News.
(SOUNDBITE OF MUSIC)
INSKEEP: This is NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.