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EurekAlert! notes:Get them while they're young: Astronomers catch exploding supernova early:
For the first time, astronomers have observed a cosmic event in great detail that they only had glimpses of before: a supernova and its explosive ejecta slamming into a nearby companion star. The discovery was made possible by a specialized survey taking advantage of recent advances in linking telescopes across the globe into a robotic network.
David Sand, an assistant professor at the University of Arizona, discovered the supernova on March 10, 2017, in the galaxy NGC 5643. At 55 million light-years, it was one of the closest supernovae discovered in recent years. Designated SN 2017cbv, it was found by the DLT40 survey, which stands for "Distance Less Than 40 Megaparsecs" or 120 million light-years. The survey uses the PROMPT telescope in Chile, which monitors roughly 500 galaxies nightly.
"This was one of the earliest catches ever -- within a day, perhaps even hours, of its explosion," said Sand, who created the DLT40 survey together with Stefano Valenti, an assistant professor at the University of California, Davis. Both were previously postdoctoral researchers at Las Cumbres Observatory, or LCO.
[...] This study infers that the white dwarf was stealing matter from a much larger companion star, approximately 20 times the radius of the sun. This caused the white dwarf to explode, and the collision of the supernova with the companion star shocked the supernova material, heating it to a blue glow that was heavy in ultraviolet light. Such a shock could not have been produced if the companion were another white dwarf star, the study's authors say.
"We've been looking for this effect -- a supernova crashing into its companion star -- since it was predicted in 2010," said Griffin Hosseinzadeh, a doctoral student at the University of California, Santa Barbara, who led the study, which is soon to be published in The Astrophysical Journal Letters. "Hints have been seen before, but this time the evidence is overwhelming. The data are beautiful!
[...] On average, only one supernova goes off over the course of a century in a galaxy like our Milky Way, according to Sand. Add to that their fleeting nature, and it becomes clear why a targeted observational campaign such as the DLT40 survey and an automated network of observatories such as the LCO are critical to their discovery and study. Funded by the National Science Foundation, The DLT40 survey started in October 2016 and is scheduled to continue over the next three years.
(Score: 2) by DannyB on Tuesday August 15 2017, @05:13PM (1 child)
It's great they have observed a new supernova so early after it explodes.
It probably won't be the last time we see one during the time humans have the technology to do so. (which may not be that much longer)
It's too bad that observations of supernovae seem to accumulate so slowly.
If they only happen once a century, and we just found one, maybe the NSF could save money by not looking for another century?
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(Score: 0) by Anonymous Coward on Tuesday August 15 2017, @09:03PM
Local supernovae may be only about every hundred years (See Tycho's stella nova [wikipedia.org], and Kepler's), but do you have any idea how many galaxies are out there, and how many of them are not not like the Milky Way?