APOD: The Crab Nebula from Visible to X-Ray (2024 Jul 23)

[APOD Robot]

The Crab Nebula from Visible to X-Ray

Explanation: What powers the Crab Nebula? A city-sized magnetized neutron star spinning around 30 times a second. Known as the Crab Pulsar, it is the bright spot in the center of the gaseous swirl at the nebula's core. About 10 light-years across, the spectacular picture of the Crab Nebula (M1) frames a swirling central disk and complex filaments of surrounding and expanding glowing gas. The picture combines visible light from the Hubble Space Telescope in red and blue with X-ray light from the Chandra X-ray Observatory shown in white, and diffuse X-ray emission detected by Imaging X-ray Polarimetry Explorer (IXPE) in diffuse purple. The central pulsar powers the Crab Nebula's emission and expansion by slightly slowing its spin rate, which drives out a wind of energetic electrons. The [url=https://chandra.harvard.edu/photo/2024/25th/more.html" >featured image</a> released today, the <a href="https://chandra.harvard.edu/25th/]25th Anniversary[/url] of the launch of NASA's flagship-class X-ray Observatory: Chandra.

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[Ann]

The Crab Nebula from Visible to X-Ray Image Credit: NASA, ESA, ASI, Hubble, Chandra, IXPE

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I wasn't aware that the disk surrounding the central neutron star was so relatively large. If the entire Crab Nebula is 10 light-years across, then I guess that the swirling disk must be at least 2 light-years in diameter. Halfway to Proxima Centauri!

Anyway, NASA had better make good use of the Chandra X-ray Telescope now before they retire it. It is such a shame that Chandra will be decommissioned, because the telescope has performed extremely well, has shown no great signs of aging, and is the best X-ray telescope in existence anywhere, unless I am mistaken.

Ann

[Roy]

Looks like two annular rings with a jet or ejection down from the center.
Anyway, we can calculate the average expansion velocity of the nebula - given a diameter of 10 ly, radius of 5 ly, 946 years from first observed to image referenced for Hubble visible light (2000 - 1054) = 1585 kilometers per second. Enormous amount of energy released to start that off.

[Sa Ji Tario]

Looks like two annular rings with a jet or ejection down from the center.
Anyway, we can calculate the average expansion velocity of the nebula - given a diameter of 10 ly, radius of 5 ly, 946 years from first observed to image referenced for Hubble visible light (2000 - 1054) = 1585 kilometers per second. Enormous amount of energy released to start that off.

There are stars that generate winds of 2,000-3,000 k/s

[Chris Peterson]

Looks like two annular rings with a jet or ejection down from the center.
Anyway, we can calculate the average expansion velocity of the nebula - given a diameter of 10 ly, radius of 5 ly, 946 years from first observed to image referenced for Hubble visible light (2000 - 1054) = 1585 kilometers per second. Enormous amount of energy released to start that off.

There are stars that generate winds of 2,000-3,000 k/s

Yes, but (kinetic) energy is proportional to mass and velocity squared. The important point here is mass. The total mass that is moving here is many orders of magnitude greater than the mass of any stellar wind.

[Bird_Man]

The Crab Nebula from Visible to X-Ray Image Credit: NASA, ESA, ASI, Hubble, Chandra, IXPE

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Anyway, NASA had better make good use of the Chandra X-ray Telescope now before they retire it. It is such a shame that Chandra will be decommissioned, because the telescope has performed extremely well, has shown no great signs of aging, and is the best X-ray telescope in existence anywhere, unless I am mistaken.

Ann

Ann makes a good point and apparently isn't the only astronomer that thinks it's important to save the Chandra X-ray Telescope. Here is an interesting NPR article on the topic: https://www.npr.org/2024/07/23/nx-s1-50 ... nniversary

[johnnydeep]

The Crab Nebula from Visible to X-Ray Image Credit: NASA, ESA, ASI, Hubble, Chandra, IXPE

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Anyway, NASA had better make good use of the Chandra X-ray Telescope now before they retire it. It is such a shame that Chandra will be decommissioned, because the telescope has performed extremely well, has shown no great signs of aging, and is the best X-ray telescope in existence anywhere, unless I am mistaken.

Ann

Ann makes a good point and apparently isn't the only astronomer that thinks it's important to save the Chandra X-ray Telescope. Here is an interesting NPR article on the topic: https://www.npr.org/2024/07/23/nx-s1-50 ... nniversary

Agreed. I can't believe that such a mundane thing as a limited budget is the problem here (though, yes, even NASA has to contend with the earthly realm every now and then). You'd think that at least ONE so-called "tech billionaire" would come to the rescue and donate funds.

[Christian G.]

If only Lord Rosse could see modern images of the "crab" he first drew in the 19th century!

What a baffling object…

[Avalon]

What a spectacular image! I assume there is another jet shooting out on the other side of the disc? What sets that pulsar rotating so incredibly fast?

[Chris Peterson]

What a spectacular image! I assume there is another jet shooting out on the other side of the disc? What sets that pulsar rotating so incredibly fast?

Conservation of angular momentum. The same thing that speeds up a figure skater when they pull in their arms.

[AVAO]

The Crab Nebula from Visible to X-Ray

Explanation: What powers the Crab Nebula? A city-sized magnetized neutron star spinning around 30 times a second. Known as the Crab Pulsar, it is the bright spot in the center of the gaseous swirl at the nebula's core. About 10 light-years across, the spectacular picture of the Crab Nebula (M1) frames a swirling central disk and complex filaments of surrounding and expanding glowing gas. The picture combines visible light from the Hubble Space Telescope in red and blue with X-ray light from the Chandra X-ray Observatory shown in white, and diffuse X-ray emission detected by Imaging X-ray Polarimetry Explorer (IXPE) in diffuse purple. The central pulsar powers the Crab Nebula's emission and expansion by slightly slowing its spin rate, which drives out a wind of energetic electrons. The [url=https://chandra.harvard.edu/photo/2024/25th/more.html" >featured image</a> released today, the <a href="https://chandra.harvard.edu/25th/]25th Anniversary[/url] of the launch of NASA's flagship-class X-ray Observatory: Chandra.

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Judy in the NEW YORK TIMES. Cogratulations!

Out There
Watch These Supernovas Explode Across Time
For the 25th anniversary of the Chandra X-ray Observatory, NASA produced ghostly time-lapse videos of two centuries-old stellar eruptions.
Published July 12, 2024

https://www.nytimes.com/2024/07/12/scie ... =url-share

A time-lapse video, assembled from images collected over two decades by the Chandra X-ray Observatory, shows the Crab Nebula, a supernova explosion first observed in 1054.CreditCredit...NASA/CXC/SAO; Image Processing: NASA/CXC/SAO/J. Schmidt, J. Major, A. Jubett, K. Arcand