Starship Asterisk*

Waves of the Great Lacerta Nebula

Explanation: It is one of the largest nebulas on the sky -- why isn't it better known? Roughly the same angular size as the Andromeda Galaxy, the Great Lacerta Nebula can be found toward the constellation of the Lizard (Lacerta). The emission nebula is difficult to see with wide-field binoculars because it is so faint, but also usually difficult to see with a large telescope because it is so great in angle -- spanning about three degrees. The depth, breadth, waves, and beauty of the nebula -- cataloged as Sharpless 126 (Sh2-126) -- can best be seen and appreciated with a long duration camera exposure. The featured image is one such combined exposure -- in this case 10 hours over five different colors and over six nights during this past June and July at the IC Astronomy Observatory in Spain. The hydrogen gas in the Great Lacerta Nebula glows red because it is excited by light from the bright star 10 Lacertae, one of the bright blue stars just above the red-glowing nebula's center. The stars and nebula are about 1,200 light years distant.

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Hooray, I love the magnificent blue O-type star 10 Lacerta and its billowing elegant nebula!
I like the nebula even better when it is seen at another orientation, so that the two major red "waves" of the nebula look like the legs of a dancing figure:




The second of the two Thomas Henne images is annotated, so that you can find the names of all the stars and bits of nebulosity in the 10 Lacerta nebula region!

Ann

...interesting to compare with IR...


Jac berne (flickr) superposition (IRIS)

AVAO wrote: ↑Wed Sep 14, 2022 6:17 am ...interesting to compare with IR...


Jac berne (flickr) superposition (IRIS)

Thanks, AVAO, how interesting!


So that strange gray translucent thing protruding into the red Lacerta nebula is the end part of a long dust lane, then?

I guess it has been truncated and has had its end part flare out into an arc, almost like a sausage, because of the stellar winds of 10 Lacerta.

Ann

So dim, it is hard to see! So glad APOD showed it to us! What is kitty is peeking at?

So how do we know that 10 Lacerta is the star causing the red hydrogen emission? I see other potential blue candidate stars in there. Is 10 Lacerta the only one at the right distance? And for that matter, how do we know the distance to the nebula itself? Parallax or some other method?

[ Also, using links to Spotify content is new! Or at least I've never seen that done before on APOD. ]

Ann wrote: ↑Wed Sep 14, 2022 6:58 am So that strange gray translucent thing protruding into the red Lacerta nebula is the end part of a long dust lane, then?
I guess it has been truncated and has had its end part flare out into an arc, almost like a sausage, because of the stellar winds of 10 Lacerta.
Ann

ThanX Ann

I'm unsure about this point. On the left Lick Hα 233 (Markarian 914) is one of the Herbig (1960) Ae/Be stars. It seems he's causing quite a stir around .

Jac




https://www.flickr.com/photos/185130090 ... 8/sizes/o/
jac berne (flickr)

AVAO wrote: ↑Wed Sep 14, 2022 9:03 pm

Ann wrote: ↑Wed Sep 14, 2022 6:58 am So that strange gray translucent thing protruding into the red Lacerta nebula is the end part of a long dust lane, then?
I guess it has been truncated and has had its end part flare out into an arc, almost like a sausage, because of the stellar winds of 10 Lacerta.
Ann

ThanX Ann

I'm unsure about this point. On the left Lick Hα 233 (Markarian 914) is one of the Herbig (1960) Ae/Be stars. It seems he's causing quite a stir around .

Jac




https://www.flickr.com/photos/185130090 ... 8/sizes/o/
jac berne (flickr)

Thanks, AVAO, but groan!

"Markarian 914" doesn't sound like a star to me. I asked Simbad Astronomical Database to take me to Markarian 914, and this is what it said to me: It's a galaxy!

I found your source for the Lick Hα 233 (Markarian 914) thing. It is this:

Taniguchi et al. wrote:

The identification of the Markarian galaxy 914 as Lick H-alpha 233, one of the Herbig (1960) Ae/Be stars, is confirmed by the small radial velocity exhibited in the observations reported. Since the spectral type of Lk H-alpha 233 is about A7, the nebulosity around it is due to reflection. It is noted that, in a Schmidt survey with a low dispersion prism, it is difficult to distinguish Markarian galaxies from nebulous objects in the Galaxy. Radial velocity measurements therefore provide one with reliable judgments.

At least Simbad found an object for me when I asked for Markarian 914. When I asked for Lick Hα 233, Simbad rejected my request.

There may be an Ae/Be star in the bright arc of LBN 437, but if so, I can't find it and don't know its designation.

Can you tell me which of the stars in your picture would be this Ae/Be star? Okay, it's this thing, right? I have to admit it doesn't look much (or anything) like a galaxy to me.


Ann

Ann wrote: ↑Thu Sep 15, 2022 4:19 am Thanks, AVAO, but groan!

"Markarian 914" doesn't sound like a star to me. I asked Simbad Astronomical Database to take me to Markarian 914, and this is what it said to me: It's a galaxy!

I found your source for the Lick Hα 233 (Markarian 914) thing. It is this:

Taniguchi et al. wrote:

The identification of the Markarian galaxy 914 as Lick H-alpha 233, one of the Herbig (1960) Ae/Be stars, is confirmed by the small radial velocity exhibited in the observations reported. Since the spectral type of Lk H-alpha 233 is about A7, the nebulosity around it is due to reflection. It is noted that, in a Schmidt survey with a low dispersion prism, it is difficult to distinguish Markarian galaxies from nebulous objects in the Galaxy. Radial velocity measurements therefore provide one with reliable judgments.

At least Simbad found an object for me when I asked for Markarian 914. When I asked for Lick Hα 233, Simbad rejected my request.

There may be an Ae/Be star in the bright arc of LBN 437, but if so, I can't find it and don't know its designation.
Can you tell me which of the stars in your picture would be this Ae/Be star? Okay, it's this thing, right? I have to admit it doesn't look much (or anything) like a galaxy to me.

Possible Ae Be star in LBN 437 in Lacerta nebula AVAO.png

Ann

..The star is very dominant in IR and can only be found under Markarian 914 in Aladin. I think it was misclassified as a galaxy at an earlier point in time...