Starship Asterisk*

[quote=AVAO post_id=339221 time=1716325304 user_id=144694]

ThanX Ann

Your hypothesis regarding gamma velorum is bold, but I also think correct.

Regarding the two YSOs, I find MASS_J073439.9-465548 (1) particularly noteworthy.
This seems to be in an intermediate stage and is almost floating freely in space.
According to the classical view, stripped of its dusty birth shell.


[img2]https://www.watson.ch/imgdb/0a73/Qx,E,0,0,1500,1304,625,543,250,217/7417834464816709[/img2]
[url]https://www.watson.ch/wissen/astronomie/186745930-dark-energy-camera-macht-neue-aufnahme-der-kometenkugel-cg4[/url]
[/quote]

Thanks, Jac!

However, NOIRLab doesn't agree with me about Gamma Velorum:


[quote][url=https://noirlab.edu/public/news/noirlab2412/?lang]NOIRLab[/url] wrote:

While astronomers have observed these structures throughout the Milky Way, the overwhelming majority of them, including CG 4, are found within a huge patch of glowing gas called the Gum Nebula. [b][color=#0040FF]Believed to be the expanding remains of a supernova that took place about a million years ago, the Gum Nebula is currently known to contain at least 31 cometary globules in addition to CG 4.[/color][/b]

....

The second idea is that cometary globules are shaped by a combination of stellar winds and radiation pressure from nearby hot, massive stars. In fact, all of the cometary globules found within the Gum Nebula appear to have tails pointing away from the center of the nebula, which is where the Vela Supernova Remnant and Vela Pulsar are located. [b][color=#0040FF]The Vela Pulsar is a rapidly spinning neutron star that was formed when a massive star collapsed, and it’s possible that its stellar winds and radiation pressure are shaping the nearby globules[/color][/b].[/quote]



[img3="The smiley face of the Vela pulsar may be the source that has sculpted the cometary globules in the vicinity of the Vela supernova remnant. Credit: X-RAY: (IXPE) FEI XIE, MSFC/NASA & (CHANDRA) SAO/CXC/NASA; OPTICAL: CHANDRA, STSCI HUBBLE/NASA, PROCESSING BY JUDY SCHMIDT; HUBBLE/CHANDRA/IXPE PROCESSING & COMPOSITING BY KIMBERLY ARCAND & NANCY WOLK, SAO/CXC/NASA"]https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2023/10/100523_ZS_highest-energy-pulsars_vela_feat.jpg?resize=1030%2C580&ssl=1[/img3]


Ann

Cometary globules are, in principle, the same kind of objects as the Pillars of Creation, and even pretty much the same objects as the little "pillars" along the rim of planetary nebulas. They are "what remains standing" after hot stars have blown away thinner material around them. The pillars are typically most massive in their "heads", and the "heads" shield the area immediately below them, creating the elongated structures.



[float=left][img3="The Pillars of Creation (below center, and also at upper left) in the Eagle Nebula. Hot bright stars in cluster NGC 6611 are sculpting the pillars. Credit: ESA."]https://www.esa.int/var/esa/storage/images/esa_multimedia/videos/2011/12/m16_the_eagle_nebula/8108830-8-eng-GB/M16_the_Eagle_Nebula_pillars.jpg[/img3][/float][float=right][img3="These cometary knots are found along the inner rim of the Helix Nebula. They all point at the central blisteringly hot white dwarf. Credit: C. Robert O'Dell and Kerry P. Handron (Rice University), NASA"]https://upload.wikimedia.org/wikipedia/commons/thumb/1/16/Helix-nebula-detail-hubble.jpg/459px-Helix-nebula-detail-hubble.jpg[/img3][/float]
[clear][/clear]
Ann

[quote=Ann post_id=339215 time=1716266992 user_id=129702]
I always want to put things in perspective.


[img3="CG4: The Globule and the Galaxy.
Image Credit: CTIO, NOIRLab, DOE, NSF, AURA; Processing: T. A. Rector (U. Alaska Anchorage/NSF’s NOIRLab), D. de Martin & M. Zamani (NSF’s NOIRLab)"]https://apod.nasa.gov/apod/image/2405/Cg4Galaxy_CtioRector_960.jpg[/img3]


Why is that globule cometary? What made it open its mouth? Nearby hot bright stars, sure. What stars?

I found the coordinates for CG4, which is the name of this thing, and saw that it is located relatively close to Gamma Velorum, an enormous powerhouse in constellation Vela, the Sail. So I googled CG4 + Gamma Velorum and found... nothing.

This is the best I can do to show you where CG4 is in relation to Gamma Velorum:


[float=left][img3="Gamma Velorum (bright star at lower right) and the Vela supernova remnant. Credit: Robert Gendler, Roberto Colombari, Digitized Sky Survey (POSS II)"]https://apod.nasa.gov/apod/image/1901/Vela-DSS-New-SS1024.jpg[/img3][/float][float=right]Gama Velorum and this way to CG4 Gendler Columbari.png[c][size=85][color=#0040FF]This way to CG4.[/color][/size][/c][/float]
[clear][/clear]


To show you why it is important to put cometary globules into perspective, consider another such globule, the Dark Tower in Scorpius:


[float=left]Dark Tower in Scorpius and NGC 6231 by Gerald Rhemann.png[c][size=85][color=#0040FF]The Dark Tower in Scorpius and star cluster NGC 6231.
Credit: Gerald Rehmann.[/color][/size][/c][/float]
[clear][/clear]


So, yeah. Perspective is important. Gerald Rehmann showed us why the Dark Tower in Scorpius and the massive open cluster NGC 6231 belong together. Now we really need a picture that shows us Gamma Velorum and CG4 in the same frame.

Oh, and... why has CG4 ruptured? How about Gamma Velorum released a jet of energy some time in the past, and CG4 took a direct hit? Perhaps the [url=https://en.wikipedia.org/wiki/Wolf–Rayet_star]Wolf-Rayet[/url] component of Gamma Velorum had an outburst? It's a mean thing, [url=https://en.wikipedia.org/wiki/Gamma_Velorum]Gamma Velorum[/url].

And that galaxy that CG4 appears to be eating? Oh, it's PGC 21338, also known as ESO 257-19. It may have an active galactic nucleus, said [url=https://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ESO+257-19&submit=SIMBAD+search]Simbad[/url]. What's the distance to that thing? I don't know!

Ann
[/quote]


ThanX Ann

Your hypothesis regarding gamma velorum is bold, but I also think correct.

Regarding the two YSOs, I find MASS_J073439.9-465548 (1) particularly noteworthy.
This seems to be in an intermediate stage and is almost floating freely in space.
According to the classical view, stripped of its dusty birth shell.


[img2]https://www.watson.ch/imgdb/0a73/Qx,E,0,0,1500,1304,625,543,250,217/7417834464816709[/img2]
[url]https://www.watson.ch/wissen/astronomie/186745930-dark-energy-camera-macht-neue-aufnahme-der-kometenkugel-cg4[/url]

Yup, it's the [i]Doomsday Machine[/i] in my mind also. Let's make the name stick :)
[url]https://trekmovie.com/wp-content/uploads/2012/08/doomsday2.jpg[/url]

Very Cool image!

I am reminded of the "doomsday machine" from the original Star Trek series. :shock:

I always want to put things in perspective.


[img3="CG4: The Globule and the Galaxy.
Image Credit: CTIO, NOIRLab, DOE, NSF, AURA; Processing: T. A. Rector (U. Alaska Anchorage/NSF’s NOIRLab), D. de Martin & M. Zamani (NSF’s NOIRLab)"]https://apod.nasa.gov/apod/image/2405/Cg4Galaxy_CtioRector_960.jpg[/img3]


Why is that globule cometary? What made it open its mouth? Nearby hot bright stars, sure. What stars?

I found the coordinates for CG4, which is the name of this thing, and saw that it is located relatively close to Gamma Velorum, an enormous powerhouse in constellation Vela, the Sail. So I googled CG4 + Gamma Velorum and found... nothing.

This is the best I can do to show you where CG4 is in relation to Gamma Velorum:


[float=left][img3="Gamma Velorum (bright star at lower right) and the Vela supernova remnant. Credit: Robert Gendler, Roberto Colombari, Digitized Sky Survey (POSS II)"]https://apod.nasa.gov/apod/image/1901/Vela-DSS-New-SS1024.jpg[/img3][/float][float=right][attachment=1]Gama Velorum and this way to CG4 Gendler Columbari.png[/attachment][c][size=85][color=#0040FF]This way to CG4.[/color][/size][/c][/float]
[clear][/clear]


To show you why it is important to put cometary globules into perspective, consider another such globule, the Dark Tower in Scorpius:


[float=left][attachment=0]Dark Tower in Scorpius and NGC 6231 by Gerald Rhemann.png[/attachment][c][size=85][color=#0040FF]The Dark Tower in Scorpius and star cluster NGC 6231.
Credit: Gerald Rehmann.[/color][/size][/c][/float]
[clear][/clear]


So, yeah. Perspective is important. Gerald Rehmann showed us why the Dark Tower in Scorpius and the massive open cluster NGC 6231 belong together. Now we really need a picture that shows us Gamma Velorum and CG4 in the same frame.

Oh, and... why has CG4 ruptured? How about Gamma Velorum released a jet of energy some time in the past, and CG4 took a direct hit? Perhaps the [url=https://en.wikipedia.org/wiki/Wolf–Rayet_star]Wolf-Rayet[/url] component of Gamma Velorum had an outburst? It's a mean thing, [url=https://en.wikipedia.org/wiki/Gamma_Velorum]Gamma Velorum[/url].

And that galaxy that CG4 appears to be eating? Oh, it's PGC 21338, also known as ESO 257-19. It may have an active galactic nucleus, said [url=https://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ESO+257-19&submit=SIMBAD+search]Simbad[/url]. What's the distance to that thing? I don't know!

Ann

[url=https://apod.nasa.gov/apod/ap240521.html] [img]https://apod.nasa.gov/apod/calendar/S_240521.jpg[/img] [size=150]CG4: The Globule and the Galaxy[/size][/url]

[b] Explanation: [/b] Can a gas cloud eat a galaxy? It's not even close. The "claw" of this odd looking "creature" in the [url=https://noirlab.edu/public/images/noirlab2412a/]featured photo[/url] is a gas cloud known as a [url=https://en.wikipedia.org/wiki/cometary_globule]cometary globule[/url]. This globule, however, [url=https://ui.adsabs.harvard.edu/abs/1995A%26A...293..493G/abstract]has ruptured[/url]. Cometary [url=https://apod.nasa.gov/apod/ap221212.html]globules[/url] are typically characterized by [url=https://apod.nasa.gov/apod/lib/glossary.html#dust]dusty[/url] heads and elongated [url=https://ui.adsabs.harvard.edu/abs/1996ApJ...463L.105M/abstract]tails[/url]. These features cause cometary [url=https://apod.nasa.gov/apod/ap120612.html]globules[/url] to have visual similarities to [url=https://apod.nasa.gov/apod/ap170409.html]comet[/url]s, but in reality they are very much different. [url=https://en.wikipedia.org/wiki/Dark_nebula]Globules[/url] are frequently the birthplaces of stars, and many show very young [url=https://science.nasa.gov/universe/stars/]stars[/url] in their heads. The reason for the rupture in the head of [url=https://noirlab.edu/public/news/noirlab2412/]this object[/url] is not yet known. The [url=http://en.wikipedia.org/wiki/Galaxy]galaxy[/url] to the left of the globule is huge, very far in the distance, and only placed near [url=https://en.wikipedia.org/wiki/CG_4]CG4[/url] by [url=https://blogmais.files.wordpress.com/2008/04/imagem_ht_07-04-23.jpg]chance superposition[/url].


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