Comments and questions about the
APOD on the main view screen.
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SugarMan
- Asternaut
- Posts: 2
- Joined: Wed Nov 15, 2023 5:51 am
Post
by SugarMan » Wed Nov 15, 2023 5:59 am
I noticed that the APOD website posted the same photo twice. The photo is very beautiful and impressive, but I wonder why it was posted twice on different dates. Maybe it was a mistake or a glitch in the system. Or maybe the editors liked it so much that they wanted to share it again.
https://apod.nasa.gov/apod/ap231109.html
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Lasse H
- Ensign
- Posts: 68
- Joined: Mon Jul 30, 2007 4:11 pm
- Location: Stockholm
Post
by Lasse H » Wed Nov 15, 2023 10:15 am
The idea this time was, I guess, to show the difference in size by giving us the chance to compare it to the older photo.
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AVAO
- Commander
- Posts: 802
- Joined: Tue May 28, 2019 12:24 pm
- AKA: multiwavelength traveller
- Location: Zurich, Switzerland
Post
by AVAO » Wed Nov 15, 2023 11:08 am
...Crab Nebula (one decade time-lapse movie:
https://www.astrobin.com/327338/0/
Observation sequences of M1, showing the expansion of shock waves emanating from the Pulsar interacting with the surrounding nebula. Chandra X-Rays (left), Hubble Visible light (right). (Credit: NASA, JPL-Caltech)
https://hubblesite.org/contents/media/v ... Video.html
Credit:NASA/ESA
http://cosmicneighbors.net/crab.htm Copyright: Mike Keith
"To the upper right of the nebula is a star in motion. This is the magnitude-11.5 star TYC 1309-1640-1 and it has a high proper motion of about 1/4 arcseconds per year. The image scale here is about 1 arcsecond per pixel, so from 1955 to 2014 it moves (2014-1955)/4 = 15 arcseconds = 15 pixels."
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Christian G.
- Science Officer
- Posts: 261
- Joined: Sat Apr 08, 2023 10:37 pm
Post
by Christian G. » Wed Nov 15, 2023 12:33 pm
AVAO wrote: ↑Wed Nov 15, 2023 11:08 am
...Crab Nebula (one decade time-lapse movie:
https://www.astrobin.com/327338/0/
Observation sequences of M1, showing the expansion of shock waves emanating from the Pulsar interacting with the surrounding nebula. Chandra X-Rays (left), Hubble Visible light (right). (Credit: NASA, JPL-Caltech)
https://hubblesite.org/contents/media/v ... Video.html
Credit:NASA/ESA
http://cosmicneighbors.net/crab.htm Copyright: Mike Keith
"To the upper right of the nebula is a star in motion. This is the magnitude-11.5 star TYC 1309-1640-1 and it has a high proper motion of about 1/4 arcseconds per year. The image scale here is about 1 arcsecond per pixel, so from 1955 to 2014 it moves (2014-1955)/4 = 15 arcseconds = 15 pixels."
Fascinating supplement to this APOD!
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hankbernath@msn.com
Post
by hankbernath@msn.com » Wed Nov 15, 2023 2:12 pm
the two shots are different but not both in IR or visible, so it is not really comparable since IR will show features not visible to visible light. How about both in visible or both in IR in the same time span?
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Chris Peterson
- Abominable Snowman
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- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
Post
by Chris Peterson » Wed Nov 15, 2023 2:14 pm
hankbernath@msn.com wrote: ↑Wed Nov 15, 2023 2:12 pm
the two shots are different but not both in IR or visible, so it is not really comparable since IR will show features not visible to visible light. How about both in visible or both in IR in the same time span?
We've seen many such comparisons. But this one involves two very high resolution imagers that simply don't operate in the same part of the spectrum.
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Pastorian
- Ensign
- Posts: 28
- Joined: Wed Mar 28, 2012 3:30 pm
Post
by Pastorian » Wed Nov 15, 2023 3:17 pm
AVAO wrote: ↑Wed Nov 15, 2023 11:08 am
...
http://cosmicneighbors.net/crab.htm Copyright: Mike Keith
"To the upper right of the nebula is a star in motion. This is the magnitude-11.5 star TYC 1309-1640-1 and it has a high proper motion of about 1/4 arcseconds per year. The image scale here is about 1 arcsecond per pixel, so from 1955 to 2014 it moves (2014-1955)/4 = 15 arcseconds = 15 pixels."
"G 100-20 -- a high proper-motion star near M1"
https://cs.astronomy.com/asy/m/nebulae/490961.aspx
High proper motion star.jpg-1000x0.jpg
"While the evolving nebula is the main actor here, if you look carefully you will find a bonus in the image. On the upper left side, there is a star clearly moving. It is G 100-20, an high proper motion (0.24″/year) star. From its paralax, we find it to be at 58 light years from us."
https://www.virtualtelescope.eu/2021/02 ... -sequence/
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orin stepanek
- Plutopian
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- Location: Nebraska
Post
by orin stepanek » Wed Nov 15, 2023 8:06 pm
Crab_Hubble_998.jpg
Don't go too close to the Crab; very dangerous to do so!
HyadesLodriguss900_labels.jpg
The Hyades!
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Orin
Smile today; tomorrow's another day!