APOD: Cygnus Shell Supernova Remnant W63 (2018 Nov 02)

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APOD Robot
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APOD: Cygnus Shell Supernova Remnant W63 (2018 Nov 02)

Post by APOD Robot » Fri Nov 02, 2018 4:10 am

Image Cygnus Shell Supernova Remnant W63

Explanation: The ghost of a long-dead star, the W63 supernova remnant shines like a faint cosmic smoke-ring along the plane of the Milky Way galaxy toward the northern constellation Cygnus the swan. Its wraithlike appearance is traced against the region's rich complex of interstellar clouds and dust by an eerie blue glow. Spanning over four full moons on the sky, the beautiful image is a telescopic mosaic in twelve panels that combines 100 hours of exposure time using narrow band filters. It shows characteristic light from ionized atoms of sulfur, hydrogen and oxygen in red, green, and blue hues. Likely over 5,000 light-years away, the visible part of the still expanding shell supernova remnant is around 150 light-years in diameter. So far no source has been identified as with the remains of W63's original star. Light from the star's supernova explosion would have reached Earth over 15,000 years ago.

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RoyHoward

Re: APOD: Cygnus Shell Supernova Remnant W63 (2018 Nov 02)

Post by RoyHoward » Fri Nov 02, 2018 5:28 am

The remnant cannot be 150 light years in diameter, if it is 5000 light years away and exploded 15,000 years ago.

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Ann
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Re: APOD: Cygnus Shell Supernova Remnant W63 (2018 Nov 02)

Post by Ann » Fri Nov 02, 2018 6:03 am

RoyHoward wrote: Fri Nov 02, 2018 5:28 am The remnant cannot be 150 light years in diameter, if it is 5000 light years away and exploded 15,000 years ago.
The fact that the supernova remnant is likely about 5,000 light years away has no bearing on the fact that the supernova progenitor exploded about 15,000 years ago and the remnant has grown to a size of about 150 light years.

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Re: APOD: Cygnus Shell Supernova Remnant W63 (2018 Nov 02)

Post by Boomer12k » Fri Nov 02, 2018 7:22 am

RoyHoward wrote: Fri Nov 02, 2018 5:28 am The remnant cannot be 150 light years in diameter, if it is 5000 light years away and exploded 15,000 years ago.
It is not that it exploded 15,000 years ago...it is that it exploded around 20,000 years ago...and the light from it reached Earth...15,000 years ago.... see?

It is an OLD supernova...

Re-read it...

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Re: APOD: Cygnus Shell Supernova Remnant W63 (2018 Nov 02)

Post by De58te » Fri Nov 02, 2018 9:37 am

RoyHoward wrote: Fri Nov 02, 2018 5:28 am The remnant cannot be 150 light years in diameter, if it is 5000 light years away and exploded 15,000 years ago.
Sure it can. I don't recall whether astronomers have calculated the speed of particles expelled in a supernova explosion, but it can't be at the speed of light or the particles would have to be mass-less. For example the Sun is about 8.2 light minutes away, i.e. light from the Sun takes that long to reach Earth. However the ionized particles from a solar flare take around 24 hours, give or take a couple hours, to get here and make the Northern or Southern Lights. That is how satellite owners know when to prepare for solar flares. So figure out the speed by dividing the speed of light by the difference between 8 minutes and 24 hours. (It is early, I am still having breakfast.)

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Re: APOD: Cygnus Shell Supernova Remnant W63 (2018 Nov 02)

Post by BDanielMayfield » Fri Nov 02, 2018 12:52 pm

APOD Robot wrote: Fri Nov 02, 2018 4:10 am So far no source has been identified as with the remains of W63's original star.
So, no smoking gun, just smoke. This suggests that either (a) a black hole was formed, or (b) the progenitor star was totally disrupted. What are the odds between these two possibilities?
Just as zero is not equal to infinity, everything coming from nothing is illogical.

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Re: APOD: Cygnus Shell Supernova Remnant W63 (2018 Nov 02)

Post by Chris Peterson » Fri Nov 02, 2018 1:20 pm

BDanielMayfield wrote: Fri Nov 02, 2018 12:52 pm
APOD Robot wrote: Fri Nov 02, 2018 4:10 am So far no source has been identified as with the remains of W63's original star.
So, no smoking gun, just smoke. This suggests that either (a) a black hole was formed, or (b) the progenitor star was totally disrupted. What are the odds between these two possibilities?
Not the latter... that doesn't happen. We either got a stellar mass black hole (which we would be unable to detect) or a neutron star (which could be very difficult to find around a remnant this old, which no longer has enough structure to define a center).
Chris

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Re: APOD: Cygnus Shell Supernova Remnant W63 (2018 Nov 02)

Post by starsurfer » Fri Nov 02, 2018 1:53 pm

For anyone wondering, the W stands for Westerhout, a catalogue of radio sources.

I love all the different supernova remnants in Cygnus, there's more than the Veil Nebula especially G65.3+5.7.

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