Starship Asterisk*

Sh2 155: The Cave Nebula

Explanation: This colorful skyscape features the dusty, reddish glow of Sharpless catalog emission region Sh2-155, the Cave Nebula. About 2,400 light-years away, the scene lies along the plane of our Milky Way Galaxy toward the royal northern constellation of Cepheus. Astronomical explorations of the region reveal that it has formed at the boundary of the massive Cepheus B molecular cloud and the hot, young, blue stars of the Cepheus OB 3 association. The bright rim of ionized hydrogen gas is energized by the radiation from the hot stars, dominated by the bright blue O-type star above picture center. Radiation driven ionization fronts are likely triggering collapsing cores and new star formation within. Appropriately sized for a stellar nursery, the cosmic cave is over 10 light-years across.

<< Previous APOD

This Day in APOD

Next APOD >>

[/b]

Whoops, Otto was still in government shutdown mode. How could I forget to flip that switch?

geckzilla wrote:Whoops, Otto was still in government shutdown mode. How could I forget to flip that switch?

No problemento, geckzilla. Now, if you would be so kind, could you flip the switch that explains why it is called the Cave Nebula I don't see any resemblance to a cave, what-so-ever.

Beyond wrote:

geckzilla wrote:Whoops, Otto was still in government shutdown mode. How could I forget to flip that switch?

No problemento, geckzilla. Now, if you would be so kind, could you flip the switch that explains why it is called the Cave Nebula I don't see any resemblance to a cave, what-so-ever.

I guess it is that huge, dark, opening on the left????

But the right side of that area looks like a Bat Demon's Head......BAT CAVE NEBULA????

Nice picture.

:---[===] *

That's a very nice image!

I checked the area with my software, and the blue stars are indeed very young. All are main sequence stars, and none is evolved, even though massive stars like these ones evolve very quickly.

All the brighter stars in the picture are far away. Even the red star is pretty far away, but it is a foreground object nonetheless. Its parallax is just a bit larger than the parallaxes of the blue stars, and its proper motion is quite different. I also think that the red star is a little bit less affected by dust than the blue stars, although I can't be sure. The blue stars are all quite reddened by all the dust around them. Most of them have apparent B-V indexes around +0.6, similar to the B-V index of the Sun, but in reality they have color indexes around -0.2.

According to my software there are at least two O stars among these stellar youngsters. Apart from the one at top, there is also the one at bottom right, whose lower diffraction spikes have been "cut off"!

Ann

Yay Jimmy Walker's finally got an APOD!

I have to agree with Beyond: I don't see any semblance to a cave!

orin stepanek wrote:

Beyond wrote:
I don't see any resemblance to a cave, what-so-ever.

I have to agree with Beyond:
I don't see any semblance to a cave!

• What a bunch of troglodytes!

Cave, n. [F. cave, L. cavus hollow, whence cavea cavity.]

• 1. A hollow place in the earth, either natural or artificial; a subterraneous cavity; a cavern; a den.
  
  2. Any hollow place, or part; a cavity. [Obs.] "The cave of the ear." Bacon.

Astronomer's are Platonist's so they have lots of ideas. Socrates had a whole Parable on a Cave. Unfortunately when you went in all the ideas you ran into were bright and shiny.

starsurfer wrote:Yay Jimmy Walker's finally got an APOD!

Yes, but he should change the color of the words that are in light-grey(?) on his home-page, so they are more easily readable.

neufer wrote:

orin stepanek wrote:

Beyond wrote:
I don't see any resemblance to a cave, what-so-ever.

I have to agree with Beyond:
I don't see any semblance to a cave!

• What a bunch of troglodytes!

Cave, n. [F. cave, L. cavus hollow, whence cavea cavity.]

• 1. A hollow place in the earth, either natural or artificial; a subterraneous cavity; a cavern; a den.
  
  2. Any hollow place, or part; a cavity. [Obs.] "The cave of the ear." Bacon.

I 'cave-in' at trying to grasp the meaning of this post.

bactame wrote:
Astronomer's are Platonist's so they have lots of ideas.

Socrates had a whole Parable on a Cave.

Unfortunately when you went in all the ideas you ran into were bright and shiny.

orin stepanek wrote:I have to agree with Beyond: I don't see any semblance to a cave!

Rotate the image 90deg counterclockwise and the cave will appear

BMAONE23 wrote:

orin stepanek wrote:I have to agree with Beyond: I don't see any semblance to a cave!

Rotate the image 90deg counterclockwise and the cave will appear

Hey... wait a minute...

Nope Still no cave. Perhaps if there was a photo from an old antique telescope with a lot less definition
And...
I'll have an extra large fries and strawberry shake with the Big Mac.

Suitable APOD for the Halloween Season: the Cave Nebula Wizard.

I see Death's scythe in that cropped view, Psnarf.

Sigh, i don't.

I seem to be in Beyonder Land on this too. I'm rarely able to see what others see in these sorts of images. We must be less suggestible than most, B.

Rob

rstevenson wrote:I seem to be in Beyonder Land on this too. I'm rarely able to see what others see in these sorts of images. We must be less suggestible than most, B.

Rob

Rob, maybe we're just the "sanest" and don't know it?

Beyond wrote:

rstevenson wrote:I seem to be in Beyonder Land on this too. I'm rarely able to see what others see in these sorts of images. We must be less suggestible than most, B.

Rob

Rob, maybe we're just the "sanest" and don't know it?

Hey: I see a cave! Oh! That's in Rob's donut!

I was going to say I saw a duckie and a horsie, but I changed my mind.

Ann

orin stepanek wrote:I have to agree with Beyond: I don't see any semblance to a cave!

Try this image by Anthony Ayiomamitis.

http://www.perseus.gr/Astro-DSO-Nebulae-Sh2-155-Hab.htm

Anthony Barreiro wrote:

orin stepanek wrote:I have to agree with Beyond: I don't see any semblance to a cave!

Try this image by Anthony Ayiomamitis.

http://www.perseus.gr/Astro-DSO-Nebulae-Sh2-155-Hab.htm

Well, there does seem to be a cave type area on the right side, but i can't tell if the picture is the same as the APOD.

Beyond wrote:

Anthony Barreiro wrote:

orin stepanek wrote:I have to agree with Beyond: I don't see any semblance to a cave!

Try this image by Anthony Ayiomamitis.

http://www.perseus.gr/Astro-DSO-Nebulae-Sh2-155-Hab.htm

Well, there does seem to be a cave type area on the right side, but i can't tell if the picture is the same as the APOD.

It's Sh2-155, the same emission nebula, just a monochrome picture of a wider field.