by Ann » Fri Oct 13, 2023 6:04 am
Nice APOD! I particularly like all the bubble nebulas:
- APOD 13 October 2023 detail.png (214.31 KiB) Viewed 18449 times
And just check out the spiral arm at lower left! It's full of bubbles.
The "bubble nebulas" that we see in M33 are mature. Their gas is dispersing, and star formation in the center of these particular nebulas have (in most cases at least) come to an end (although low-mass star formation may possibly continue along the nebula's perimeter).
We may compare the Rosette Nebula with the Orion Nebula, where the Rosette Nebula has exhausted its gas in the center, whereas the Orion Nebula is still "full of gas" and very bright in its center:
I really appreciate today's APOD, where bright blue-white stars are seen scattered like grains of sand all over the galaxy in the full resolution image. And as I've said, all the details seen in all those emission nebulas are fascinating indeed.
Still, there is such a thing as not being able to see the forest for the trees - or, in this case,
not being able to see the trees for the forest.
Or, to be precise, not being able to see the really bright nebulas for all the scattered nebulosity seen all over the place. So I recommend a picture by Adam Block, where the bright nebulas really stand out!
Triangulum Galaxy (Messier 33). Image: Adam Block/Mount Lemmon SkyCenter/
University of Arizona
Note two really bright nebulas in M33: NGC 604 at upper right, and NGC 595 to the lower right of the yellow center of M33. A closeup of NGC 604 shows us that there are bubbles in NGC 604 as well:
And did you know that the second brightest nebula in M33 is NGC 595? I didn't, so enjoy!
Ann
Nice APOD! I particularly like all the bubble nebulas:
[float=left][img3="Hydrogen Clouds of M33.
Image Credit & Copyright: Reinhold Wittich"]https://apod.nasa.gov/apod/image/2310/M33_Triangulum1024.jpg[/img3][/float][float=right][attachment=0]APOD 13 October 2023 detail.png[/attachment][/float]
[clear][/clear]
And just check out the spiral arm at lower left! It's full of bubbles.
The "bubble nebulas" that we see in M33 are mature. Their gas is dispersing, and star formation in the center of these particular nebulas have (in most cases at least) come to an end (although low-mass star formation may possibly continue along the nebula's perimeter).
We may compare the Rosette Nebula with the Orion Nebula, where the Rosette Nebula has exhausted its gas in the center, whereas the Orion Nebula is still "full of gas" and very bright in its center:
[float=left][img3="The Rosette Nebula with a hole in its center. It is at least possible that some low-mass star formation might be taking place in some of the dust lanes seen in the nebula. Credit: Raysastrophotograhy"]https://upload.wikimedia.org/wikipedia/commons/thumb/7/7d/Rosette_Nebula_NGC_2244.jpg/1028px-Rosette_Nebula_NGC_2244.jpg[/img3][/float][float=right][img3="The Orion Nebula is still full of gas and very bright in the center. Credit: Opo Terser"]https://upload.wikimedia.org/wikipedia/commons/thumb/7/71/The_Great_Orion_Nebula_%28M42%29.jpg/742px-The_Great_Orion_Nebula_%28M42%29.jpg[/img3][/float]
[clear][/clear]
I really appreciate today's APOD, where bright blue-white stars are seen scattered like grains of sand all over the galaxy in the full resolution image. And as I've said, all the details seen in all those emission nebulas are fascinating indeed.
Still, there is such a thing as not being able to see the forest for the trees - or, in this case, [url=https://blog.pshares.org/wp-content/uploads/sites/10/2017/03/trees-e1490897032134.jpg]not being able to see the trees for the forest[/url].
Or, to be precise, not being able to see the really bright nebulas for all the scattered nebulosity seen all over the place. So I recommend a picture by Adam Block, where the bright nebulas really stand out!
[float=left][attachment=1]Messier-33[1].jpg[/attachment][c][size=85][color=#0040FF]Triangulum Galaxy (Messier 33). Image: Adam Block/Mount Lemmon SkyCenter/
University of Arizona[/color][/size][/c][/float]
[clear][/clear]
Note two really bright nebulas in M33: NGC 604 at upper right, and NGC 595 to the lower right of the yellow center of M33. A closeup of NGC 604 shows us that there are bubbles in NGC 604 as well:
[img3="This is a composite Chandra and Hubble Telescope image of NGC 604, where blue represents hot gas. Note two bubbles inside NGC 604, where the one at right (west) is full of bright stars. The X-ray gas in this bubble is produced by the colliding strong winds of 200 hot stars. Note, by contrast, that the bubble to the left (east) looks 'empty'. The X-ray gas here is the remnant of old supernovas. This part of NGC 604 is considerably older than the other part. Credit: X-ray: NASA/CXC/CfA/R. Tuellmann et al.; Optical: NASA/AURA/STScI."]https://www.messier-objects.com/wp-content/uploads/2015/04/NGC-604.jpg[/img3]
And did you know that the second brightest nebula in M33 is NGC 595? I didn't, so enjoy!
[img3="NGC 595, with its cluster and surrounding nebula. Credit: en:user:Friendlystar"]https://upload.wikimedia.org/wikipedia/commons/e/e6/NGC_595.jpg[/img3]
Ann