APOD: South of Orion (2022 Jan 27)

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Expand view Topic review: APOD: South of Orion (2022 Jan 27)

Re: APOD: South of Orion (2022 Jan 27)

by neufer » Sat Jan 29, 2022 2:41 am

Chris Peterson wrote: Fri Jan 28, 2022 11:40 pm
neufer wrote: Fri Jan 28, 2022 10:42 pm
So... it was clear to you both from the Hubble image alone that this was never a Bok globule (and, presumably, that Herschel PACS far-IR 70 & 160mum maps, APEX LABOCA & SABOCA submillimeter continuum maps, and Magellan PANIC near-IR images were a waste of time) :?:
It was clear to me. And it certainly sounds like it was clear to her.
https://en.wikipedia.org/wiki/Chutzpah wrote:
<<Chutzpah is the quality of audacity, for good or for bad. Originated 1890–95 from Yiddish חוצפּה‎ (ḥuṣpâ), from Mishnaic Hebrew חוֹצְפָּה‎ (ḥôṣǝpâ), from חָצַף‎ (ḥāṣap, “to be insolent”). Ultimately from Aramaic חֲצִיפָא‎ (ḥăṣîpāʾ), חֲצַף‎ (ḥaṣap, “to be barefaced, insolent”). In Hebrew, chutzpah is used indignantly, to describe someone who has overstepped the boundaries of accepted behavior. In traditional usage, the word expresses a strong sense of disapproval, condemnation and outrage.

Leo Rosten in The Joys of Yiddish defines chutzpah as "gall, brazen nerve, effrontery, incredible 'guts', presumption plus arrogance such as no other word and no other language can do justice to". In this sense, chutzpah expresses both strong disapproval and condemnation. In the same work, Rosten also defines the term as "that quality enshrined in a man who, having killed his mother and father, throws himself on the mercy of the court because he is an orphan."

Chutzpah amounts to a total denial of personal responsibility, which renders others speechless and incredulous ... one cannot quite believe that another person totally lacks common human traits like remorse, regret, guilt, sympathy and insight. The implication is at least some degree of psychopathy in the subject, as well as the awestruck amazement of the observer at the display.>>

Re: APOD: South of Orion (2022 Jan 27)

by bystander » Sat Jan 29, 2022 12:42 am

Tom Glenn wrote: Fri Jan 28, 2022 4:49 pm FYI the discussion link for today's APOD (January 28) still directs to this page, and the date on the APOD landing page above the image is incorrect (still says January 27). This glitch also causes the APOD for the 27th to be skipped if you click "<" to see the previous APOD.
Tekija wrote: Fri Jan 28, 2022 6:59 pm This is the link to discuss today’s image:
http://asterisk.apod.com/viewtopic.php?t=42178

The APOD for 2022 Jan 28 has been fixed with the correct date and links for Previous, Discuss, and Next.

Re: APOD: South of Orion (2022 Jan 27)

by Chris Peterson » Fri Jan 28, 2022 11:40 pm

neufer wrote: Fri Jan 28, 2022 10:42 pm
Chris Peterson wrote: Fri Jan 28, 2022 8:00 pm
dlmartin7@cogeco.ca wrote: Fri Jan 28, 2022 6:48 pm
With Ann and Peterson sparing, one can only conclude that this discussion is one for the ages.
But we're not. We're in agreement.
  • Indeed.... for you wrote:
Chris Peterson wrote: Thu Jan 27, 2022 5:48 pm
I'm mainly responding to her claim "It is so clear from the Hubble image that NGC 1999 is a cavity." I guess that is subject to interpretation. If she means it as "the dark region in NGC 1999 is a cavity, not a dust cloud", then there is no disagreement.
So... it was clear to you both from the Hubble image alone that this was never a Bok globule (and, presumably, that Herschel PACS far-IR 70 & 160mum maps, APEX LABOCA & SABOCA submillimeter continuum maps, and Magellan PANIC near-IR images were a waste of time) :?:
It was clear to me. And it certainly sounds like it was clear to her. It was only the choice of wording that made it sound like she was saying the NGC object and the cavity were one and the same. Which she has said she wasn't. So... no issue.

Re: APOD: South of Orion (2022 Jan 27)

by neufer » Fri Jan 28, 2022 10:42 pm

Chris Peterson wrote: Fri Jan 28, 2022 8:00 pm
dlmartin7@cogeco.ca wrote: Fri Jan 28, 2022 6:48 pm
With Ann and Peterson sparing, one can only conclude that this discussion is one for the ages.
But we're not. We're in agreement.
  • Indeed.... for you wrote:
Chris Peterson wrote: Thu Jan 27, 2022 5:48 pm
I'm mainly responding to her claim "It is so clear from the Hubble image that NGC 1999 is a cavity." I guess that is subject to interpretation. If she means it as "the dark region in NGC 1999 is a cavity, not a dust cloud", then there is no disagreement.
So... it was clear to you both from the Hubble image alone that this was never a Bok globule (and, presumably, that Herschel PACS far-IR 70 & 160mum maps, APEX LABOCA & SABOCA submillimeter continuum maps, and Magellan PANIC near-IR images were a waste of time) :?:
https://arxiv.org/abs/1005.2202 wrote:
Hier ist wahrhaftig ein Loch im Himmel - The NGC 1999 dark globule is not a globule
T. Stanke, A. M. Stutz, J. J. Tobin, B. Ali, S. T. Megeath, O. Krause, H. Linz, L. Allen, E. Bergin, N. Calvet, J. Di Francesco, W. J. Fischer, E. Furlan, L. Hartmann, T. Henning, P. Manoj, S. Maret, J. Muzerolle, P. C. Myers, D. Neufeld, M. Osorio, K. Pontoppidan, C. A. Poteet, D. M. Watson, T. Wilson
[Submitted on 12 May 2010]

The NGC 1999 reflection nebula features a dark patch with a size of ~10,000 AU, which has been interpreted as a small, dense foreground globule and possible site of imminent star formation. We present Herschel PACS far-infrared 70 and 160mum maps, which reveal a flux deficit at the location of the globule. We estimate the globule mass needed to produce such an absorption feature to be a few tenths to a few Msun. Inspired by this Herschel observation, we obtained APEX LABOCA and SABOCA submillimeter continuum maps, and Magellan PANIC near-infrared images of the region. We do not detect a submillimer source at the location of the Herschel flux decrement; furthermore our observations place an upper limit on the mass of the globule of ~2.4x10-2 Msun. Indeed, the submillimeter maps appear to show a flux depression as well. Furthermore, the near-infrared images detect faint background stars that are less affected by extinction inside the dark patch than in its surroundings. We suggest that the dark patch is in fact a hole or cavity in the material producing the NGC 1999 reflection nebula, excavated by protostellar jets from the V 380 Ori multiple system.

Re: APOD: South of Orion (2022 Jan 27)

by johnnydeep » Fri Jan 28, 2022 9:13 pm

My, this thread has turned into a storm in a teapot, or perhaps a cavity in a nebula :)

Re: APOD: South of Orion (2022 Jan 27)

by Chris Peterson » Fri Jan 28, 2022 8:00 pm

dlmartin7@cogeco.ca wrote: Fri Jan 28, 2022 6:48 pm With Ann and Peterson sparing, one can only conclude that this discussion is one for the ages.
But we're not. We're in agreement.

Re: APOD: South of Orion (2022 Jan 27)

by neufer » Fri Jan 28, 2022 7:45 pm

dlmartin7@cogeco.ca wrote: Fri Jan 28, 2022 6:48 pm
With Ann and Peterson sparing, one can only conclude that this discussion is one for the ages.
https://www.etymonline.com/search?q=spare wrote:
spare (v.) Old English sparian "to refrain from harming, be indulgent to, allow to go free; use sparingly," from the source of Old English spær "sparing, frugal," from Proto-Germanic *sparaz (source also of Old Saxon sparon, Old Frisian sparia, Old Norse spara, Dutch sparen, Old High German sparon, German sparen "to spare"). Meaning "to dispense from one's own stock, give or yield up," is recorded from early 13c. Related: Spared; sparing.
----------------------------------------------------------------------------------
spar (v.) late 14c., "go quickly, rush, dart, spring;" c. 1400, "to strike or thrust," perhaps from French esparer "to kick" (Modern French éparer), from Italian sparare "to fling," from Latin ex- (see ex-) + parare "make ready, prepare," hence "ward off, parry." Used in 17c. in reference to preliminary actions in a cock fight; figurative sense of "to dispute, bandy with words" is from 1690s. Extension to humans, in a literal sense, with meaning "to engage in or practice boxing" is attested from 1755. Related: Sparred; sparring.

Re: APOD: South of Orion (2022 Jan 27)

by Tekija » Fri Jan 28, 2022 6:59 pm

This is the link to discuss today’s image:

http://asterisk.apod.com/viewtopic.php?t=42178

Re: APOD: South of Orion (2022 Jan 27)

by dlmartin7@cogeco.ca » Fri Jan 28, 2022 6:48 pm

With Ann and Peterson sparing, one can only conclude that this discussion is one for the ages.

Re: APOD: South of Orion (2022 Jan 27)

by Tom Glenn » Fri Jan 28, 2022 4:49 pm

FYI the discussion link for today's APOD (January 28) still directs to this page, and the date on the APOD landing page above the image is incorrect (still says January 27). This glitch also causes the APOD for the 27th to be skipped if you click "<" to see the previous APOD.

Re: APOD: South of Orion (2022 Jan 27)

by Chris Peterson » Fri Jan 28, 2022 4:06 pm

bystander wrote: Fri Jan 28, 2022 3:52 pm
Chris Peterson wrote: Fri Jan 28, 2022 1:55 pm Find something wrong in a Wikipedia article? Fix it! That's how the system works. It depends upon community input and correction.
The error wasn't in the wikipedia article NGC 1999, but in the text accompanying the image File:Ngc1999.jpg which was taken from HubbleSite. It's a little harder to correct STScI and NASA.
Directly, yes. Indirectly? We'll see. I sent a message through their contact page suggesting they review the content on that 22 year old page.

Re: APOD: South of Orion (2022 Jan 27)

by bystander » Fri Jan 28, 2022 3:52 pm

Chris Peterson wrote: Fri Jan 28, 2022 1:55 pm Find something wrong in a Wikipedia article? Fix it! That's how the system works. It depends upon community input and correction.
The error wasn't in the wikipedia article NGC 1999, but in the text accompanying the image File:Ngc1999.jpg which was taken from HubbleSite. It's a little harder to correct STScI and NASA.

Re: APOD: South of Orion (2022 Jan 27)

by Chris Peterson » Fri Jan 28, 2022 1:55 pm

Ann wrote: Fri Jan 28, 2022 5:44 am
Grumpy woman.png

Grumpy woman speaks (in a loud voice:

Chris, you should check Ann's quote before asserting that Wikipedia doesn't say what she claims it is saying! Go to https://en.wikipedia.org/wiki/NGC_1999, click on the top image, and note that the caption that appears as the new page opens is exactly the one she quoted!

Ann, you should realize that not everyone knows what "NGC" means (New General Catalogue), or that it lists only bright objects. Not everyone understands that a dark object can't be an NGC object, so it was wrong of you to say that "NGC 1999 is a cavity", when it is really the name of a bright reflection nebula (with a cavity in its center)!

Ann
Find something wrong in a Wikipedia article? Fix it! That's how the system works. It depends upon community input and correction.

Re: APOD: South of Orion (2022 Jan 27)

by Ann » Fri Jan 28, 2022 5:44 am

Grumpy woman.png
Grumpy woman.png (158.21 KiB) Viewed 9280 times

Grumpy woman speaks (in a loud voice:

Chris, you should check Ann's quote before asserting that Wikipedia doesn't say what she claims it is saying! Go to https://en.wikipedia.org/wiki/NGC_1999, click on the top image, and note that the caption that appears as the new page opens is exactly the one she quoted!

Ann, you should realize that not everyone knows what "NGC" means (New General Catalogue), or that it lists only bright objects. Not everyone understands that a dark object can't be an NGC object, so it was wrong of you to say that "NGC 1999 is a cavity", when it is really the name of a bright reflection nebula (with a cavity in its center)!

Ann

Re: APOD: South of Orion (2022 Jan 27)

by Ann » Thu Jan 27, 2022 7:04 pm

Chris Peterson wrote: Thu Jan 27, 2022 6:39 pm
Ann wrote: Thu Jan 27, 2022 6:22 pm
Chris Peterson wrote: Thu Jan 27, 2022 5:48 pm
I'm mainly responding to her claim "It is so clear from the Hubble image that NGC 1999 is a cavity." I guess that is subject to interpretation. If she means it as "the dark region in NGC 1999 is a cavity, not a dust cloud", then there is no disagreement. In any case, however, Wikipedia has it right. As Wikipedia nearly always does.
Yes, Chris, that is obviously what I meant, namely, that the dark object in the center of NGC 1999 is a cavity, not that NGC 1999 itself is a cavity rather than a dusty nebula. After all, what NGC designation could possibly refer to a cavity only, or any old pitch-black object only??? But my point was that the astronomers who first took a look at the Hubble image of NGC 1999 couldn't quite believe that the dark object in the center of this dusty nebula was a cavity.

And I want to thank Tekija for noticing that I was quoting the caption of the Wikipedia image in Wikimedia Commons, which indeed still claims that the dark "T" in NGC 1999 is a dark Bok globule. Thank you, Tekija! :D

Ann
Hmm. One person's "obvious"...



This is Ann. :arrow:


She has made 11737 posts at Starship Asterisk*, and she still believes that "NGC" means "Nothing! Gluck! Cluck!". (And she can't spell, either!)


(And she is wearing a blue dress, too. Or a blue something. She isn't too sartorially gifted.)


(But those pearls must be her mother's. They are not Ann's. Or maybe they are stars that Ann picked from the sky? Maybe some of the pearls are Orion's Belt, because the name of one of the stars there - Alnilam? - means "A string of pearls". Maybe Orion is missing his belt tonight? Maybe the nothingness where Orion's Belt used to be is the new NGC object in the sky? Nothing gluck cluck! says Ann.)


(And Ann seems to have stolen Crux, too, and now she is wearing Crux as an ear ring. And look at those spiral swirls on various parts of her body. Surely they are galaxies? What galaxies have Ann stolen, I wonder?)


Ann

Re: APOD: South of Orion (2022 Jan 27)

by neufer » Thu Jan 27, 2022 6:40 pm

Ann wrote: Thu Jan 27, 2022 6:22 pm
Chris Peterson wrote: Thu Jan 27, 2022 5:48 pm
Tekija wrote: Thu Jan 27, 2022 5:44 pm
Ann was misled by the caption of the Wikipedia image in Wikimedia Commons that, as it should, cites the original HHT caption? The text on the Wikipedia, on the other hand, was corrected to refer to a hole on 16 May 2010, according to the page edit history. And Chris perhaps did not notice that Ann had cited the old image caption, not current text? Hence the apparent disagreement?
I'm mainly responding to her claim "It is so clear from the Hubble image that NGC 1999 is a cavity." I guess that is subject to interpretation. If she means it as "the dark region in NGC 1999 is a cavity, not a dust cloud", then there is no disagreement. In any case, however, Wikipedia has it right. As Wikipedia nearly always does.
Yes, Chris, that is obviously what I meant, namely, that the dark object in the center of NGC 1999 is a cavity, not that NGC 1999 itself is a cavity rather than a dusty nebula.
Chris Peterson wrote: Thu Jan 27, 2022 6:39 pm
Hmm. One person's "obvious"...
Obviously, what Ann meant to say was: Yes, Chris, that is obliviously what I meant,
Ann wrote: Thu Jan 27, 2022 6:22 pm
After all, what NGC designation could possibly refer to a cavity only, or any old pitch-black object only??? But my point was that the astronomers who first took a look at the Hubble image of NGC 1999 couldn't quite believe that the dark object in the center of this dusty nebula was a cavity.
Then you should say what you mean,” the March Hare went on.

I do,” Alice hastily replied; “at least—at least I mean what I say—that’s the same thing, you know.

Not the same thing a bit!” said the Hatter. “You might just as well say that ‘I see what I eat’ is the same thing as ‘I eat what I see’!

You might just as well say,” added the March Hare, “that ‘I like what I get’ is the same thing as ‘I get what I like’!

You might just as well say,” added the Dormouse, who seemed to be talking in his sleep, “that ‘I breathe when I sleep’ is the same thing as ‘I sleep when I breathe’!

It is the same thing with you,” said the Hatter, and here the conversation dropped, and the party sat silent for a minute, while Alice thought over all she could remember about ravens and writing-desks, which wasn’t much.
Ann wrote: Thu Jan 27, 2022 6:22 pm
And I want to thank Tekija for noticing that I was quoting the caption of the Wikipedia image in Wikimedia Commons, which indeed still claims that the dark "T" in NGC 1999 is a dark Bok globule.
Why not just complain to NASA directly:
https://hubblesite.org/contents/media/images/2000/10/952-Image.html wrote:
Click to play embedded YouTube video.

<<The WFPC2 image of NGC 1999 shows a remarkable jet-black cloud near its center, resembling a letter T tilted on its side, located just to the right and lower right of the bright star. This dark cloud is an example of a "Bok globule," named after the late University of Arizona astronomer Bart Bok. The globule is a cold cloud of gas, molecules, and cosmic dust, which is so dense it blocks all of the light behind it. In the Hubble image, the globule is seen silhouetted against the reflection nebula illuminated by V380 Orionis. Astronomers believe that new stars may be forming inside Bok globules, through the contraction of the dust and molecular gas under their own gravity.>>

Re: APOD: South of Orion (2022 Jan 27)

by Chris Peterson » Thu Jan 27, 2022 6:39 pm

Ann wrote: Thu Jan 27, 2022 6:22 pm
Chris Peterson wrote: Thu Jan 27, 2022 5:48 pm
Tekija wrote: Thu Jan 27, 2022 5:44 pm

Ann was misled by the caption of the Wikipedia image in Wikimedia Commons that, as it should, cites the original HHT caption? The text on the Wikipedia, on the other hand, was corrected to refer to a hole on 16 May 2010, according to the page edit history. And Chris perhaps did not notice that Ann had cited the old image caption, not current text? Hence the apparent disagreement?
I'm mainly responding to her claim "It is so clear from the Hubble image that NGC 1999 is a cavity." I guess that is subject to interpretation. If she means it as "the dark region in NGC 1999 is a cavity, not a dust cloud", then there is no disagreement. In any case, however, Wikipedia has it right. As Wikipedia nearly always does.
Yes, Chris, that is obviously what I meant, namely, that the dark object in the center of NGC 1999 is a cavity, not that NGC 1999 itself is a cavity rather than a dusty nebula. After all, what NGC designation could possibly refer to a cavity only, or any old pitch-black object only??? But my point was that the astronomers who first took a look at the Hubble image of NGC 1999 couldn't quite believe that the dark object in the center of this dusty nebula was a cavity.

And I want to thank Tekija for noticing that I was quoting the caption of the Wikipedia image in Wikimedia Commons, which indeed still claims that the dark "T" in NGC 1999 is a dark Bok globule. Thank you, Tekija! :D

Ann
Hmm. One person's "obvious"...

Re: APOD: South of Orion (2022 Jan 27)

by Ann » Thu Jan 27, 2022 6:22 pm

Chris Peterson wrote: Thu Jan 27, 2022 5:48 pm
Tekija wrote: Thu Jan 27, 2022 5:44 pm
Chris Peterson wrote: Thu Jan 27, 2022 4:21 pm

Hmm: "NGC 1999 is a dust-filled bright nebula with a vast hole of empty space represented by a black patch of sky, as can be seen in the photograph. It is a reflection nebula, and shines from the light of the variable star V380 Orionis." I don't see how many ways that can be read. I don't see how it is in any way inaccurate.

NGC 1999 is most certainly not the cavity. We don't name cavities this way. This object is a structure that contains a cavity. Every authoritative reference defines it as a reflection nebula.
Ann was misled by the caption of the Wikipedia image in Wikimedia Commons that, as it should, cites the original HHT caption? The text on the Wikipedia, on the other hand, was corrected to refer to a hole on 16 May 2010, according to the page edit history. And Chris perhaps did not notice that Ann had cited the old image caption, not current text? Hence the apparent disagreement?
I'm mainly responding to her claim "It is so clear from the Hubble image that NGC 1999 is a cavity." I guess that is subject to interpretation. If she means it as "the dark region in NGC 1999 is a cavity, not a dust cloud", then there is no disagreement. In any case, however, Wikipedia has it right. As Wikipedia nearly always does.
Yes, Chris, that is obviously what I meant, namely, that the dark region in the center of NGC 1999 is a cavity, not that NGC 1999 itself is a cavity rather than a dusty nebula. After all, what NGC designation could possibly refer to a cavity only, or any pitch-black region only???

NGC 7764A annotated with arrow.png
Could there be an NGC object there?

But my point was that the astronomers who first took a look at the Hubble image of NGC 1999 couldn't quite believe that the dark object in the center of this dusty nebula was a cavity.

And I want to thank Tekija for noticing that I was quoting the caption of the Wikipedia image in Wikimedia Commons, which indeed still claims that the dark "T" in NGC 1999 is a dark Bok globule. Thank you, Tekija! :D

Ann

Re: APOD: South of Orion (2022 Jan 27)

by neufer » Thu Jan 27, 2022 6:22 pm

Click to play embedded YouTube video.
Chris Peterson wrote: Thu Jan 27, 2022 5:48 pm
Tekija wrote: Thu Jan 27, 2022 5:44 pm
Ann was misled by the caption of the Wikipedia image in Wikimedia Commons that, as it should, cites the original HHT caption? The text on the Wikipedia, on the other hand, was corrected to refer to a hole on 16 May 2010, according to the page edit history. And Chris perhaps did not notice that Ann had cited the old image caption, not current text? Hence the apparent disagreement?
I'm mainly responding to her claim "It is so clear from the Hubble image that NGC 1999 is a cavity." I guess that is subject to interpretation. If she means it as "the dark region in NGC 1999 is a cavity, not a dust cloud", then there is no disagreement.

Re: APOD: South of Orion (2022 Jan 27)

by Chris Peterson » Thu Jan 27, 2022 6:00 pm

Tekija wrote: Thu Jan 27, 2022 5:49 pm And Ann did not by my reading intentionally confuse the hole with the nebula but thought the hole was still referred to as Bok globule.
Certainly possible.

Re: APOD: South of Orion (2022 Jan 27)

by Tekija » Thu Jan 27, 2022 5:49 pm

And Ann did not by my reading intentionally confuse the hole with the nebula but thought the hole was still referred to as Bok globule.

Re: APOD: South of Orion (2022 Jan 27)

by Chris Peterson » Thu Jan 27, 2022 5:48 pm

Tekija wrote: Thu Jan 27, 2022 5:44 pm
Chris Peterson wrote: Thu Jan 27, 2022 4:21 pm
Ann wrote: Thu Jan 27, 2022 4:06 pm

You and I are reading that Wikipedia entry differently, Chris. :wink:
Hmm: "NGC 1999 is a dust-filled bright nebula with a vast hole of empty space represented by a black patch of sky, as can be seen in the photograph. It is a reflection nebula, and shines from the light of the variable star V380 Orionis." I don't see how many ways that can be read. I don't see how it is in any way inaccurate.

NGC 1999 is most certainly not the cavity. We don't name cavities this way. This object is a structure that contains a cavity. Every authoritative reference defines it as a reflection nebula.
Ann was misled by the caption of the Wikipedia image in Wikimedia Commons that, as it should, cites the original HHT caption? The text on the Wikipedia, on the other hand, was corrected to refer to a hole on 16 May 2010, according to the page edit history. And Chris perhaps did not notice that Ann had cited the old image caption, not current text? Hence the apparent disagreement?
I'm mainly responding to her claim "It is so clear from the Hubble image that NGC 1999 is a cavity." I guess that is subject to interpretation. If she means it as "the dark region in NGC 1999 is a cavity, not a dust cloud", then there is no disagreement. In any case, however, Wikipedia has it right. As Wikipedia nearly always does.

Re: APOD: South of Orion (2022 Jan 27)

by Tekija » Thu Jan 27, 2022 5:44 pm

Chris Peterson wrote: Thu Jan 27, 2022 4:21 pm
Ann wrote: Thu Jan 27, 2022 4:06 pm
Chris Peterson wrote: Thu Jan 27, 2022 2:15 pm
The Wikipedia entry sounds perfectly correct. NGC 1999 is not a cavity. It is a dusty reflection nebula with a cavity in its center.
You and I are reading that Wikipedia entry differently, Chris. :wink:
Hmm: "NGC 1999 is a dust-filled bright nebula with a vast hole of empty space represented by a black patch of sky, as can be seen in the photograph. It is a reflection nebula, and shines from the light of the variable star V380 Orionis." I don't see how many ways that can be read. I don't see how it is in any way inaccurate.

NGC 1999 is most certainly not the cavity. We don't name cavities this way. This object is a structure that contains a cavity. Every authoritative reference defines it as a reflection nebula.
Ann was misled by the caption of the Wikipedia image in Wikimedia Commons that, as it should, cites the original HHT caption? The text on the Wikipedia, on the other hand, was corrected to refer to a hole on 16 May 2010, according to the page edit history. And Chris perhaps did not notice that Ann had cited the old image caption, not current text? Hence the apparent disagreement?

Re: APOD: South of Orion (2022 Jan 27)

by Chris Peterson » Thu Jan 27, 2022 4:21 pm

Ann wrote: Thu Jan 27, 2022 4:06 pm
Chris Peterson wrote: Thu Jan 27, 2022 2:15 pm
Ann wrote: Thu Jan 27, 2022 7:32 am
It is so clear from the Hubble image that NGC 1999 is a cavity. The incredible void in it makes it a unique object, at least among objects so far catalogued by astronomers. Imagine the jet that punched through the rather thick nebula here and left this T-shaped scar! This "black hole", or "hole-y T", completely baffled astronomers when they first saw the Hubble image of NGC 1999 back in the year 2000, and they thought that the T was a dust cloud. Indeed, a Wikipedia page is still telling us it is a dust cloud!!! No no no, Wikipedia!!
The Wikipedia entry sounds perfectly correct. NGC 1999 is not a cavity. It is a dusty reflection nebula with a cavity in its center.
You and I are reading that Wikipedia entry differently, Chris. :wink:
Hmm: "NGC 1999 is a dust-filled bright nebula with a vast hole of empty space represented by a black patch of sky, as can be seen in the photograph. It is a reflection nebula, and shines from the light of the variable star V380 Orionis." I don't see how many ways that can be read. I don't see how it is in any way inaccurate.

NGC 1999 is most certainly not the cavity. We don't name cavities this way. This object is a structure that contains a cavity. Every authoritative reference defines it as a reflection nebula.

Re: APOD: South of Orion (2022 Jan 27)

by Ann » Thu Jan 27, 2022 4:06 pm

Chris Peterson wrote: Thu Jan 27, 2022 2:15 pm
Ann wrote: Thu Jan 27, 2022 7:32 am
It is so clear from the Hubble image that NGC 1999 is a cavity. The incredible void in it makes it a unique object, at least among objects so far catalogued by astronomers. Imagine the jet that punched through the rather thick nebula here and left this T-shaped scar! This "black hole", or "hole-y T", completely baffled astronomers when they first saw the Hubble image of NGC 1999 back in the year 2000, and they thought that the T was a dust cloud. Indeed, a Wikipedia page is still telling us it is a dust cloud!!! No no no, Wikipedia!!
The Wikipedia entry sounds perfectly correct. NGC 1999 is not a cavity. It is a dusty reflection nebula with a cavity in its center.
You and I are reading that Wikipedia entry differently, Chris. :wink:

Ann

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