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M83: Star Streams and a Thousand Rubies

Explanation: Big, bright, and beautiful, spiral galaxy M83 lies a mere twelve million light-years away, near the southeastern tip of the very long constellation Hydra. About 40,000 light-years across, M83 is known as the Southern Pinwheel for its pronounced spiral arms. But the wealth of reddish star forming regions found near the edges of the arms' thick dust lanes, also suggest another popular moniker for M83, the Thousand-Ruby Galaxy. This new deep telescopic digital image also records the bright galaxy's faint, extended halo. Arcing toward the bottom of the cosmic frame lies a stellar tidal stream, debris drawn from massive M83 by the gravitational disruption of a smaller, merging satellite galaxy. Astronomers David Malin and Brian Hadley found the elusive star stream in the mid 1990s by enhancing photographic plates.

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Minor point about the discoverers of the faint arc: David Malin was chiefly the Anglo Australian Telescope's photographic scientist as well as contributing as a research astronomer; Brian Hadley was the chief photographer of the Royal Observatory Edinburgh's Photolabs unit, working with UK Schmidt telescope plates.

Today's APOD shows a long stellar stream emanating from M83. (Unfortunately, the picture is so big that I have to post it as an attachment.) Ah yes, but there is still more to M83 than meets the eye in the APOD!


Note that the orientation is different in the two images. In the APOD, south is up, but in the two-panel image at right, north is up.

I believe that the "bright" disk of M83 is smallish, but with its extended arms, it becomes huge.

Other smallish galaxies also have extended arms:


With its extended arms small NGC 4625 suddenly looks as large (or larger) than its neighbor, NGC 4618.


Another interesting example of extended arms (of stars of otherwise) is dwarf galaxy NGC 4214. Hubble has shown that this galaxy has a disk of old stars and a few hotspots of starburst:


With the gas surrounding it, NGC 4214 suddenly becomes a spiral galaxy! Fancy that!

But the very opposite thing happens, too, when gas recedes from the outer parts of the galaxy and is only found near the center of the galaxy:


So in NGC 4314, a tiny ring of gas and dust is all the gas there is in this galaxy!


Ann

Hello,

Please, the navigate backward link (<) is pointing to the AP of July, 28th. It's supposed to be July, 2nd's.

thank you

Where is the smaller galaxy that is pulling on the arc? Or is the smaller galaxy already merged with M83?

Happy 4th of July, it's our independence day once again and freedom is back that's why we can freely see the pictures of these stars & galaxies. Speaking of M83 galaxy, we can see sun-like stars and exoplanets here if we focus our attention, and just like Milky Way life possibly evolving here. So, a study of M83 is worth a thousand rubies.

MelvzLuster wrote: ↑Wed Jul 03, 2024 5:51 pm Happy 4th of July, it's our independence day once again and freedom is back that's why we can freely see the pictures of these stars & galaxies. Speaking of M83 galaxy, we can see sun-like stars and exoplanets here if we focus our attention, and just like Milky Way life possibly evolving here. So, a study of M83 is worth a thousand rubies.

Though I was about to doubt your claim that we "can see sun-like stars and exoplanets here if we focus our attention", that indeed seems possible. Here's a story about a possible exoplanet in the Whirlpool Galaxy (M51), which is 28 million lightyears away:

https://science.nasa.gov/universe/exopl ... ur-galaxy/

And I can whole-heartedly agree with your last statement! - "So, a study of M83 is worth a thousand rubies"

Finally, I'll note that Wikipedia lists a greatly larger diameter for M83: 118,000 ly:

https://en.wikipedia.org/wiki/Messier_8 ... cteristics

36.24 kiloparsecs (118,000 light-years)
(diameter; 26.0 mag/arcsec2 B-band isophote)

SpaceCadet wrote: ↑Wed Jul 03, 2024 4:34 pm Where is the smaller galaxy that is pulling on the arc? Or is the smaller galaxy already merged with M83?

A quick googling turned up no info on a small galaxy pulling on M83. With the help of my software, I found a small galaxy, PGC 47885 or MCG-05-32-042, whose radial velocity is very similar to that of M83, which means that it is probably located quite close to M83. This galaxy is so small and faint that I doubt that you can find a lot of info on it except what Simbad offers.

PGC 47885 is located so relatively far from M83 that we can't see it in the APOD.

Three galaxies apart from M83 itself is visible in the APOD:


The only galaxy I have managed to identify is #3, PGC 48123 or ESO 444-85. This is most definitely a background galaxy, and my guess is that #1 and #2 are, too.

Ann

Ann wrote: ↑Wed Jul 03, 2024 7:21 pm

SpaceCadet wrote: ↑Wed Jul 03, 2024 4:34 pm Where is the smaller galaxy that is pulling on the arc? Or is the smaller galaxy already merged with M83?

A quick googling turned up no info on a small galaxy pulling in M83. With the help of my software, I found a small galaxy, PGC 47885 or MCG-05-32-042, whose radial velocity is very similar to that of M83, which means that it is probably located quite close to M83. This galaxy is so small and faint that I doubt that you can find a lot of info on it except what Simbad offers.

PGC 47885 is located so relatively far from M83 that we can't see it in the APOD.

Three galaxies apart from M83 itself is visible in the APOD:


APOD 3 July 2024 annotated.png


The only galaxy I have managed to identify is #3, PGC 48123 or ESO 444-85. This is most definitely a background galaxy, and my guess is that #1 and #2 are, too.

Ann

ThanX Ann

I don't have a concrete answer to that either. I only find it remarkable how the distant galaxy number 3 looks in the light from Spitzer.
Jac

Original data: NASA/ESA SST versus HST jac berne (flickr)

AVAO wrote: ↑Wed Jul 03, 2024 8:25 pm

Ann wrote: ↑Wed Jul 03, 2024 7:21 pm

SpaceCadet wrote: ↑Wed Jul 03, 2024 4:34 pm Where is the smaller galaxy that is pulling on the arc? Or is the smaller galaxy already merged with M83?

A quick googling turned up no info on a small galaxy pulling in M83. With the help of my software, I found a small galaxy, PGC 47885 or MCG-05-32-042, whose radial velocity is very similar to that of M83, which means that it is probably located quite close to M83. This galaxy is so small and faint that I doubt that you can find a lot of info on it except what Simbad offers.

PGC 47885 is located so relatively far from M83 that we can't see it in the APOD.

Three galaxies apart from M83 itself is visible in the APOD:


APOD 3 July 2024 annotated.png


The only galaxy I have managed to identify is #3, PGC 48123 or ESO 444-85. This is most definitely a background galaxy, and my guess is that #1 and #2 are, too.

Ann

ThanX Ann

I don't have a concrete answer to that either. I only find it remarkable how the distant galaxy number 3 looks in the light from Spitzer.
Jac

Click to view full size image 1 or image 2

Original data: NASA/ESA SST versus HST jac berne (flickr)

Click to view full size image

Beautiful as always, Jac! #3 has a strong bar and two dusty arms that bend sharply away from the bar. And I note that galaxy #2 has a very dusty center (which therefore looks very red in the Spitzer image).

Thank you, as always, for bringing out new and fascinating details in astronomical objects and posting these pictures here!

Ann

Thank you all for the insight and information. Some really amazing info came out from this!

Ann wrote: ↑Thu Jul 04, 2024 4:02 am

AVAO wrote: ↑Wed Jul 03, 2024 8:25 pm

Ann wrote: ↑Wed Jul 03, 2024 7:21 pm

A quick googling turned up no info on a small galaxy pulling in M83. With the help of my software, I found a small galaxy, PGC 47885 or MCG-05-32-042, whose radial velocity is very similar to that of M83, which means that it is probably located quite close to M83. This galaxy is so small and faint that I doubt that you can find a lot of info on it except what Simbad offers.

PGC 47885 is located so relatively far from M83 that we can't see it in the APOD.

Three galaxies apart from M83 itself is visible in the APOD:


APOD 3 July 2024 annotated.png


The only galaxy I have managed to identify is #3, PGC 48123 or ESO 444-85. This is most definitely a background galaxy, and my guess is that #1 and #2 are, too.

Ann

ThanX Ann

I don't have a concrete answer to that either. I only find it remarkable how the distant galaxy number 3 looks in the light from Spitzer.
Jac

Click to view full size image 1 or image 2

Original data: NASA/ESA SST versus HST jac berne (flickr)

Click to view full size image

Beautiful as always, Jac! #3 has a strong bar and two dusty arms that bend sharply away from the bar. And I note that galaxy #2 has a very dusty center (which therefore looks very red in the Spitzer image).

Thank you, as always, for bringing out new and fascinating details in astronomical objects and posting these pictures here!

Ann

ThanX Ann

I really like the galaxy. It is a real firework of discovery on all wavelengths.

Jac

Original data: NASA/ESA/CSA (HST/JWST) jac berne (flickr)