APOD: The Rise and Fall of Supernova 2015F (2016 Feb 09)

Comments and questions about the APOD on the main view screen.
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Ron-Astro Pharmacist
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Re: APOD: The Rise and Fall of Supernova 2015F (2016 Feb 09)

Post by Ron-Astro Pharmacist » Wed Feb 10, 2016 2:47 pm

Ann wrote:
ta152h0 wrote:this is a great catch. Was there a clue this was going to happen ?
There were no clues.

A supernova explosion explosion is like a landmine. First there is nothing, then there is a bang. Yes, if astronomers could have carefully studied the particular progenitor of SN 2015F, they just might have caught some little signs that something was about to happen.

But the particular star system that gave rise to SN 2015F would have been far, far too faint even for Hubble to study in a meaningful way. The host galaxy is about 80 million light years away, and the progenitors of SN type Ia are typically relatively faint.

And what do we mean by saying that something is "about" to happen? That might just mean that a supernova could be happening very "soon" - like, say, in a thousand years. We can hardly expect the Hubble telescope to keep a unblinking eye on every moderately nearby galaxy for the next thousand years in order to catch any possible supernova as it happens before our descendants' eyes.

Ann
I can't say I've ever heard of "high cadence monitoring observation" before attempting a search about neutrino detection of SN 2015F but this article claims to do it. Maybe someone can explain it to us?

The information it provides is "sizable" and provides "far out" information. :wink:
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Re: APOD: The Rise and Fall of Supernova 2015F (2016 Feb 09)

Post by Chris Peterson » Wed Feb 10, 2016 3:00 pm

Ron-Astro Pharmacist wrote:I can't say I've ever heard of "high cadence monitoring observation" before attempting a search about neutrino detection of SN 2015F but this article claims to do it.
It just means collecting data at a high rate (such as every few hours) for some survey objects, and hoping for a supernova. This allows the very early light curve to be recovered. When a supernova is detected (typically a day or two after it occurs) the previous high temporal resolution data can be used to study the earlier phases.
Chris

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Re: APOD: The Rise and Fall of Supernova 2015F (2016 Feb 09)

Post by neufer » Wed Feb 10, 2016 4:23 pm

bls0326 wrote:
Did any neutrino detectors report a rise in neutrino count associated with this supernova?
SN 1987A was a nearby core collapse supernova that produced a world wide observed neutrino count of 24.

Core collapse supernovae produce ~1,000 times more neutrinos than do Ia supernovae.

SN 2015F was a (neutrino poor) Ia supernova approximately 300 times further away than SN 1987A.

Hence, the expected observed # of neutrinos from SN 2015F should have been: 24/(1,000*3002) ~ 3 x 10-7.
Art Neuendorffer

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Re: APOD: The Rise and Fall of Supernova 2015F (2016 Feb 09)

Post by bls0326 » Thu Feb 11, 2016 1:04 am

Art: thanks for the numbers. Had no idea about the neutrino production difference between the types of supernova. The distance factor makes even more difference though.

Brian