APOD: The Medulla Nebula Supernova Remnant (2023 Apr 24)

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APOD: The Medulla Nebula Supernova Remnant (2023 Apr 24)

Post by APOD Robot » Mon Apr 24, 2023 4:08 am

Image The Medulla Nebula Supernova Remnant

Explanation: What powers this unusual nebula? CTB-1 is the expanding gas shell that was left when a massive star toward the constellation of Cassiopeia exploded about 10,000 years ago. The star likely detonated when it ran out of elements near its core that could create stabilizing pressure with nuclear fusion. The resulting supernova remnant, nicknamed the Medulla Nebula for its brain-like shape, still glows in visible light by the heat generated by its collision with confining interstellar gas. Why the nebula also glows in X-ray light, though, remains a mystery. One hypothesis holds that an energetic pulsar was co-created that powers the nebula with a fast outwardly moving wind. Following this lead, a pulsar has recently been found in radio waves that appears to have been expelled by the supernova explosion at over 1000 kilometers per second. Although the Medulla Nebula appears as large as a full moon, it is so faint that it took many hours of exposure with a telescope in Seven Persons, Alberta, Canada to create the featured image.

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MarkE

Re: APOD: The Medulla Nebula Supernova Remnant (2023 Apr 24)

Post by MarkE » Mon Apr 24, 2023 7:43 am

Looks similar to the Dolphin Head Nebula.

Any idea what the black/dark object is that's sitting on the outer edge of the nebula around the 4 O'clock position?

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Ann
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Re: APOD: The Medulla Nebula Supernova Remnant (2023 Apr 24)

Post by Ann » Mon Apr 24, 2023 10:06 am

MarkE wrote: Mon Apr 24, 2023 7:43 am Looks similar to the Dolphin Head Nebula.

Any idea what the black/dark object is that's sitting on the outer edge of the nebula around the 4 O'clock position?
That's a dust structure. We see many such structures in nebulas.

APOD 24 April 2023 detail.png
Dark dust structure in the Medulla nebula.
Credit: Kimberly Sibbald

As for the Medulla nebula, it has an interesting shape. It's spherical, but it clearly has a hole in it:

Medulla nebula annotated Russell Croman.png
Path of the neutron star?

Did the neutron star create this hole in the nebula as the neutron star was making its escape?


We can tell an expanding supernova shell by the fact that at least parts of its outer edges are blue or green from doubly ionized oxygen, OIII, as the expanding shell slams into the surrounding medium:

Click to play embedded YouTube video.
Expansion of the Crab Nebula. You can see some bits of blue
near the outer edges.

Ann
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Re: APOD: The Medulla Nebula Supernova Remnant (2023 Apr 24)

Post by AVAO » Mon Apr 24, 2023 10:59 am

Ann wrote: Mon Apr 24, 2023 10:06 am Did the neutron star create this hole in the nebula as the neutron star was making its escape?

Ann
Click to view full size image 1 or image 2
starless...
Image
biggg: https://live.staticflickr.com/65535/528 ... 9b09_o.jpg
jac berne (flickr)

Image
APOD 2022 October 2 viewtopic.php?t=42662

NASA's Fermi Satellite Clocks a 'Cannonball' Pulsar
https://www.youtube.com/watch?v=5pGXqrovaFo&t=115s

https://d3i71xaburhd42.cloudfront.net/c ... ure4-1.png

"Figure 4. Total intensity image of the SNR CTB 1 from the Canadian Galactic Plane Survey (CGPS) at 1.42 GHz. False colors start at brightness temperatures of 5.5 K and the maximum is at 8.9 K. The angular resolution and field-of-view are approximately 1′ and 1.9◦×1.1◦, respectively. A green cross marks the location of the geometric center of the SNR (Landecker et al. 1982) whiles circles indicate the position of PSR J0002+6216 (Clark et al. 2017). A faint tail of emission is visible from the PSR to the SNR, pointing back toward the geometric center. The inset is our higher angular resolution 20-cm VLA image of the dashed region taken from Figure 3."

https://arxiv.org/pdf/1904.07993
Last edited by AVAO on Mon Apr 24, 2023 7:46 pm, edited 4 times in total.

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Re: APOD: The Medulla Nebula Supernova Remnant (2023 Apr 24)

Post by JohnD » Mon Apr 24, 2023 2:25 pm

Kidney_glomerulus,_light_micrograph.jpg
Whoever named this "The Medulla" was sadly lacking in anatomy! While it looks nothing like a medulla, it closely resembles the Glomerulus, the primary filtration apparatus in the mammalian kidney.

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Re: APOD: The Medulla Nebula Supernova Remnant (2023 Apr 24)

Post by orin stepanek » Mon Apr 24, 2023 2:40 pm

Oops; I was thinking Medusa! :oops:
CTB1_Sibbald_960.jpg
This does make a nice APOD! 8-)
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Re: APOD: The Medulla Nebula Supernova Remnant (2023 Apr 24)

Post by Ann » Mon Apr 24, 2023 3:29 pm

AVAO wrote: Mon Apr 24, 2023 10:59 am
Ann wrote: Mon Apr 24, 2023 10:06 am Did the neutron star create this hole in the nebula as the neutron star was making its escape?

Ann
Click to view full size image 1 or image 2
Image
APOD 2022 October 2 viewtopic.php?t=42662

NASA's Fermi Satellite Clocks a 'Cannonball' Pulsar
https://www.youtube.com/watch?v=5pGXqrovaFo&t=115s

https://d3i71xaburhd42.cloudfront.net/c ... ure4-1.png

"Figure 4. Total intensity image of the SNR CTB 1 from the Canadian Galactic Plane Survey (CGPS) at 1.42 GHz. False colors start at brightness temperatures of 5.5 K and the maximum is at 8.9 K. The angular resolution and field-of-view are approximately 1′ and 1.9◦×1.1◦, respectively. A green cross marks the location of the geometric center of the SNR (Landecker et al. 1982) whiles circles indicate the position of PSR J0002+6216 (Clark et al. 2017). A faint tail of emission is visible from the PSR to the SNR, pointing back toward the geometric center. The inset is our higher angular resolution 20-cm VLA image of the dashed region taken from Figure 3."

https://arxiv.org/pdf/1904.07993
Thanks a bunch, AVAO! So the escaping neutron star has nothing to do with the strange hole in the Medulla Nebula, then.

Ann
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Uncle Jeff

Re: APOD: The Medulla Nebula Supernova Remnant (2023 Apr 24)

Post by Uncle Jeff » Tue Apr 25, 2023 12:07 am

The blurb mentions the direction of Cassiopeia, but I can't find a distance. How far away is it?

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Re: APOD: The Medulla Nebula Supernova Remnant (2023 Apr 24)

Post by Chris Peterson » Tue Apr 25, 2023 12:44 am

Uncle Jeff wrote: Tue Apr 25, 2023 12:07 am The blurb mentions the direction of Cassiopeia, but I can't find a distance. How far away is it?
About 6900 light years, but with close to a 30% uncertainty (so, 4900 - 8800 ly).
Chris

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