Another spectacular series of images from astronomy is making photo history and contributing to the sciences: yesterday astronomers from the Weizmann Institute and San Diego State University announced their measurements and records of imagery from their observations of a supernova, now published in Nature. The explosion was followed by a collapse as the star became a black hole. This is the first time in history that the formation of a black hole has ever been directly witnessed, lending credibility to the prevailing hypotheses regarding how very large stars all end up as black holes. It is also possibly the biggest explosion ever photographed.
Here’s some of the photos:
[photo credit: Weizmann Institute, Israel]
The photos show the bizarre fracturing of the supernova gas cloud as it rushes inwards.
According to the announcement at Sciencedaily.com:
Until now, none of the supernovae stars that scientists had managed to measure had exceeded a mass of 20 suns. Gal-Yam and Leonard were looking at a specific region in space using the Keck Telescope on Mauna Kea in Hawaii and the Hubble Space Telescope: supernova SN 2005gl, which was originally seen in the barred-spiral galaxy NGC 266 on October 5, 2005. (Pre-explosion pictures from the Hubble archive, taken in 1997, reveal the progenitor as a very luminous point source.) Identifying the about-to-explode star, they calculated its mass to be equal to 50-100 suns. Continued observation revealed that only a small part of the star’s mass was flung off in the explosion. Most of the material, says Gal-Yam, was drawn into the collapsing core as its gravitational pull mounted. Indeed, in subsequent telescope images of that section of the sky, the star seems to have disappeared. In other words, the star has now become a black hole – so dense that light can’t escape.
Congratulation to Dr. Gal-Yam and Dr. Leonard, theirs is an amazing accomplishment!