Starship Asterisk*

[quote=beryllium732 post_id=342147 time=1730943398 user_id=146004]
[quote=Ann post_id=342124 time=1730793779 user_id=129702]

The second thing I want you to notice is the entire right part of the thick broad central dust lane, where absolutely no star formation appears to be taking place. Indeed, star formation in the Milky Way is winding down, and we are a "green valley" galaxy, transitioning from a richly starforming "blue" galaxy into a "red and dead" one, where no (or extremely little) star formation is taking place. Between the "Blue Cloud" galaxies and the "Red Sequence" galaxies is the Green valley. We are in the valley!



Well, being in a green valley is not so bad. There are worse things.

Ann
[/quote]

That sounds really sad! I didn't know our Milky Way was that inactive. I wonder if the Andromeda galaxy also is a dead galaxy just like ours.
[/quote]

Neither Andromeda nor the Milky Way are "dead" galaxies, because both are indeed forming new stars. Our galaxy is forming about one new star per year. Andromeda, however, is forming stars at a slower rate than that.


[img3="Andromeda galaxy. Credit: Torben Hansen."]https://upload.wikimedia.org/wikipedia/commons/thumb/c/c2/M31_09-01-2011_%28cropped%29.jpg/1280px-M31_09-01-2011_%28cropped%29.jpg[/img3]


I deliberately picked an Andromeda image where the young blue stars are almost invisible. But if you look at the far left part of Andromeda, you can just make out the brightest region of star formation in Andromeda, NGC 206.


[float=left][attachment=0]NGC 206 in Andromeda Torben Hansen wiki.png[/attachment][c][size=85][color=#0040FF]NGC 206 in Andromeda.[/color][/size][/c][/float]
[clear][/clear]


Ann

It was an experience being there. Actually met the photographer at Easter Island when we were there the same week.

[quote=Ann post_id=342124 time=1730793779 user_id=129702]

The second thing I want you to notice is the entire right part of the thick broad central dust lane, where absolutely no star formation appears to be taking place. Indeed, star formation in the Milky Way is winding down, and we are a "green valley" galaxy, transitioning from a richly starforming "blue" galaxy into a "red and dead" one, where no (or extremely little) star formation is taking place. Between the "Blue Cloud" galaxies and the "Red Sequence" galaxies is the Green valley. We are in the valley!



Well, being in a green valley is not so bad. There are worse things.

Ann
[/quote]

That sounds really sad! I didn't know our Milky Way was that inactive. I wonder if the Andromeda galaxy also is a dead galaxy just like ours.

[quote="Jim Armstrong" post_id=342141 time=1730912281]
Perhaps it is only my connection to APOD that gives a photograph of a cat when the link to "Still being discovered" at the bottom is accessed.
[/quote]

It would not be an APOD without at least one caption link to a cat image.

Perhaps it is only my connection to APOD that gives a photograph of a cat when the link to "Still being discovered" at the bottom is accessed.

"Still being discovered" eh? Meow.

Moai created as units of value ?
No one knows by whom, or where, or how built, or how they were used in exchange for food, or fot portable units of trade,
Or if there are more to be found. Or where, or how they were moved and emplaced. [b]Just like Bitcoin![/b]

The statues should be looking up! Impressive image...

Forgive me for disregarding Easter Island and just looking at the Milky Way instead!


[img3="Milky Way over Easter Island
Credit & Copyright: Josh Dury"]https://apod.nasa.gov/apod/image/2411/IslandMoai_Dury_960_annotated.jpg[/img3]


Here is some of the stuff we can see in the APOD:


[attachment=1]APOD 5 November 2024 detail annotated.png[/attachment]


Here is a closeup of the Rho Ophiuchi nebular complex:


[float=left][attachment=0]Rho Ophiuchi nebular complex Astro Pixel Processor Aries Productions.png[/attachment][c][size=85][color=#0040FF]Credit: Astro Pixel Processor Aries Productions,
possibly Mabula Haverkamp[/color][/size][/c][/float]
[clear][/clear]


Baade's Window is the relatively clear and dust-free region in Sagittarius where we can see deep into the bulge of the Milky Way, quite close to the galactic center. Baade's Window is yellow from the light of millions (and possibly billions) of mostly small yellow and red stars.


[img3="The SWEEPS area is Baade's Window proper, the clearest part of the Sagittarius Star Cloud. Note the pink Lagoon Nebula above the large yellow star cloud and slightly bluish M24 near top. Credit: Akira Fuji."]https://upload.wikimedia.org/wikipedia/commons/6/61/HST_SWEEPS_Galaxy_Location-2006.jpg[/img3]


The Scutum Star Cloud is another relatively dust-free region where we see a part of the bulge of the Milky Way:


[img3="The Scutum Star Cloud. Cluster M11 is at 7 o'clock. Credit: Hypatia Alexandria."]https://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Scutum_Star_Cloud.jpg/1200px-Scutum_Star_Cloud.jpg[/img3]


There is no ongoing star formation in the Scutum Star Cloud, but rich open cluster M11 is located near one of its dust lanes:


[img3="M11 in Scutum. Credit: ESO."]https://earthsky.org/upl/2014/07/Messier-11-ESO.jpg[/img3]


M24 is the only extended region in the Milky Way that is bright from young stars:


[img3="Messier 24, the Small Sagittarius Star Cloud. Credit: Roberto Colombari."]https://upload.wikimedia.org/wikipedia/commons/c/c4/Messier_24_Colombari_crop_invert.jpg[/img3]


The most famous nebula in the Milky Way is almost certainly the Orion Nebula. The Carina Nebula, which is much larger, is also very famous. But the Lagoon Nebula, which can actually be seen in today's APOD, must certainly be one of the top three:


[img3="The Lagoon Nebula (lower center), NGC 6559 (top left) and the Trifid Nebula (top right). Note the dusty footprint outline that is connecting the Lagoon Nebula and NGC 6559. Credit: The Astronomy Enthusiast."]https://i0.wp.com/theastroenthusiast.com/wp-content/uploads/2021/08/coordinates-scaled.jpg?resize=1536%2C1016&ssl=1[/img3]


Back to the APOD. There are two things I'd like you to notice about the appearance of the Milky Way. First, that our galaxy appears to be "smoking", as smoke seems to rise from it and spread in all directions. This may be a real phenomenon, although I can't recall seeing it before.


[img3="Not just the Earth is smoking. Credit: AI."]https://img.freepik.com/premium-photo/painting-house-smoke-from-factory_869640-195450.jpg[/img3]


The second thing I want you to notice is the entire right part of the thick broad central dust lane, where absolutely no star formation appears to be taking place. Indeed, star formation in the Milky Way is winding down, and we are a "green valley" galaxy, transitioning from a richly starforming "blue" galaxy into a "red and dead" one, where no (or extremely little) star formation is taking place. Between the "Blue Cloud" galaxies and the "Red Sequence" galaxies is the Green valley. We are in the valley!


[img3="A mock-up of the galaxy color–magnitude diagram with three populations: the red sequence, the blue cloud, and the green valley. Credit: Joshua Schroeder"]https://upload.wikimedia.org/wikipedia/commons/thumb/9/96/Galaxy_color-magnitude_diagram-en.svg/1024px-Galaxy_color-magnitude_diagram-en.svg.png[/img3]


Well, being in a green valley is not so bad. There are worse things.


[img2]https://media.gettyimages.com/id/183765619/sv/foto/green-fields-and-mounatins.jpg?s=612x612&w=gi&k=20&c=V5Ao1YaTfFTlqW7L10lYycaMhjOowqJZOx0vbyE7Z8c=[/img2]

Ann

[url=https://apod.nasa.gov/apod/ap241105.html] [img]https://apod.nasa.gov/apod/calendar/S_241105.jpg[/img] [size=150]Milky Way over Easter Island[/size][/url]

[b] Explanation: [/b] Why were the statues on Easter Island built? No one is sure. What is sure is that over 900 large stone statues called [url=https://en.wikipedia.org/wiki/Moai]moai[/url]s exist there. The [url=https://en.wikipedia.org/wiki/Easter_Island]Rapa Nui (Easter Island)[/url] moais stand, on average, over twice as tall as a person and have over 200 times as much mass. It is thought that the [url=https://youtu.be/luv9B2fJIEM]unusual statues[/url] were created about 600 years ago in the images of local leaders of a vibrant and ancient civilization. Rapa Nui has been declared by [url=https://www.unesco.org/]UNESCO[/url] to a [url=https://en.wikipedia.org/wiki/World_Heritage_Site]World Heritage Site[/url]. [url=https://www.instagram.com/p/DA6GNhAslfT/]Pictured here[/url], some of the [url=https://www.pbs.org/wgbh/nova/easter/civilization/giants.html]stone giants[/url] were imaged last month under the [url=https://apod.nasa.gov/apod/ap110710.html]central band[/url] of our [url=https://science.nasa.gov/resource/the-milky-way-galaxy/]Milky Way[/url] galaxy. [url=https://www.theguardian.com/world/2023/mar/02/new-easter-island-moai-statue-discovered-in-volcano-crater]Previously unknown moais[/url] are [url=https://www.shutterstock.com/image-photo/close-scottish-fold-cat-head-600nw-1276621966.jpg]still being discovered[/url].


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