Starship Asterisk*

http://apod.nasa.gov/apod/ap090331.html

The star cluster at the center top is R136. Is the one at the bottom left (7 o'clock) Hodge 301? And was Hodge 301 formed from the same nebula (30 Doradus)?

Never mind, I found the answer to the first question (yes): Symphony of Colours in the Tarantula. But I'm still not sure if Hodge 301 was formed within the Tarantula. The caption says Hodge 301 is 10 times older than R136 and the stellar winds from Hodge 301 are responsible for the shaping of 30 Doradus, but I have yet to find any outright confirmation that Hodge 301 was formed within the Tarantula Nebula.

I'm curious about the yellow "donuts" around the perimeter of this composite. Notice that the reddish stars show diffraction spikes as we'd expect with a narrow-band filter and negligible aberrations. This is true (for at least some) all the way to the edge of the field, so I doubt off-axis aberrations are a factor. But what I'm calling "yellow donuts" (small fuzzy circles with a dimmer center) have an entirely different look. They appear to be out of focus, their dim centers an artifact of the secondary mirror. But that's not likely. And there are no yellow donuts in the center of the field. Granted, their distribution could be just a red herring.

The yellow donuts also look like bright stars embedded in a shell. The brighter edges could be a horizon effect.

But why? How? So many spherical shells in a twisted dusty nebula seems odd.

I'd love to read your thoughts.

Spherical shells? I'll have to look again .. but WOW seeing galaxies in formation is simply wonderful!

Okay .. I've looked again, and now right in the centre of the photo I see Jimi Hendrix playing Purple Haze, which has inspired me to higher artistic effort in this post

I also just noticed there are two threads on this photo. Oops for someone.

Being an astronomical doofus I ask this question. NGC 2070 is given (on that page) as referring to the star cluster within the Tarantula. Searching on NGC 2070 though - brings up pages that indicate that NGC 2070 refers to the Taranatula nebula.

??

Ray-Optics wrote:I'm curious about the yellow "donuts" around the perimeter of this composite. Notice that the reddish stars show diffraction spikes as we'd expect with a narrow-band filter and negligible aberrations. This is true (for at least some) all the way to the edge of the field, so I doubt off-axis aberrations are a factor. But what I'm calling "yellow donuts" (small fuzzy circles with a dimmer center) have an entirely different look. They appear to be out of focus, their dim centers an artifact of the secondary mirror. But that's not likely. And there are no yellow donuts in the center of the field. Granted, their distribution could be just a red herring.

The compositing that produced this image is complex. I think that the yellow blobs are an artifact of this. The very tight stars, especially where you can see diffraction patterns, are HST data. Many of the fuzzier stars are La Silla NTT data, which will have much lower resolution (and won't show diffraction patterns). The donut effect is likely what you see when you have a high resolution and low resolution star on top of each other. The distribution could be created by optical aberration: the NTT is a Richey-Chretien design, which produces large spot sizes off axis. If so, that would suggest the compositor started with a wide field NTT image and then selectively overlaid high resolution HST images, particularly near the center. It's also possible that the NTT data is from a mosaic, in which case the distribution of the bloated stars is probably just related to where the HST data was thin. That is, the NTT data is suppressed where HST data was available.

In any case, I don't think we're seeing anything other than stars in these "donuts".

"In the heart of monstrous Tarantula Nebula lies huge bubbles of energetic gas..." Despite my occasional castigations, the writers of these blurbs still seem unable or unwilling consistently to write correct prose--perhaps the sign of the narrow scientist unwilling to consider humane concerns. In any case, please don't tell me language doesn't matter. It does. Please don't tell me not to care. I always will. By the way, learning to use both sides of your brain can be fun!

saberard wrote:"In the heart of monstrous Tarantula Nebula lies huge bubbles of energetic gas..." Despite my occasional castigations, the writers of these blurbs still seem unable or unwilling consistently to write correct prose--perhaps the sign of the narrow scientist unwilling to consider humane concerns. In any case, please don't tell me language doesn't matter. It does. Please don't tell me not to care. I always will. By the way, learning to use both sides of your brain can be fun!

I'm certainly a fan of using both sides of my brain! But with both hemispheres running at full tilt, I can't seem to find just what in this mildly twisted prose is inhumane.

You are of course right , Chris, that grammatical lapses cannot tell all; and perhaps in this one instance it seems that I am making a mountain out of a molehill. However, whenever I read these interesting little blurbs and find a jarring inattentiveness to very basic grammar -- such as, here, lack of agreement of subject and verb -- I wonder what the mindset can be that implies that scientific facts are important but that language does not to seem to really matter at all. It may be a left-right brain issue or something else; but I still believe that language is as worth attention as anything else, especially the attention of someone who is writing copy for something to be read by thousands of people. In many other societies language is still important, but in ours an attitude has set in that language is, at best, inconsequential and, at worst, beneath contempt. I hope my remarks can do some good.

saberard wrote:"In the heart of monstrous Tarantula Nebula lies huge bubbles of energetic gas..." Despite my occasional castigations, the writers of these blurbs still seem unable or unwilling consistently to write correct prose--perhaps the sign of the narrow scientist unwilling to consider humane concerns. In any case, please don't tell me language doesn't matter. It does. Please don't tell me not to care. I always will. By the way, learning to use both sides of your brain can be fun!

Ah, language lover, thou art true
in urging upwards language use:
But using both sides of the brain at once
can tire us who are classed dunce.
Have mercy, thou of wordage skill,
and overlook my punctuation ills.


Okay Doc, I know you weren't writing of punctuation, but of singular-plural; but I was having trouble deciding on colon-semi-colon so the 'punctuation ills' seemed to fit.

On other lines, I wonder if the gas attains supercritical levels, or reaches an as yet unclassified category?

saberard wrote:... but I still believe that language is as worth attention as anything else, especially the attention of someone who is writing copy for something to be read by thousands of people. In many other societies language is still important, but in ours an attitude has set in that language is, at best, inconsequential and, at worst, beneath contempt. ...

I agree,Doc. I was absolutely astounded that my university level Journalism student grandaughter told me she was told to drop colons and semi-colons and use commas only. I showed her some examples of how these things clarify thought in the reading process, but how can I compete with her instructor?

Jimi Hendrix? I thought that was Timothy Leary. Oh well...
This picture does make me wonder though - does anyone know what the sky would look like to someone who lived within a nebula like this one? Say you lived on a planet in the dark, swirly, reddish part just a little above and to the right of the cluster on the bottom left. What would the universe look like to you? Would that sky look different to you than ours does to us? Would you know you lived within a nebula? Would you be able to see the gassy formations, or would it be just a minor haze?
And what would the night time sky look like if you lived on a planet within a star cluster? Would there be dozens of huge stars at night, or are the distances so vast that the stars, though plentiful, would just look like Venus or Mercury does to us?

illiontor wrote:This picture does make me wonder though - does anyone know what the sky would look like to someone who lived within a nebula like this one?

The background of the entire sky would look similar to what you see when you look at the Milky Way- that is, a kind of gray sky glow. Depending on where you were, and what the nebula was like, you might see some faint structure- again, similar to what you see in the Milky Way.

And what would the night time sky look like if you lived on a planet within a star cluster? Would there be dozens of huge stars at night, or are the distances so vast that the stars, though plentiful, would just look like Venus or Mercury does to us?

You'd see a lot of very bright stars. As you suggest, similar to our brighter planets. There would be enough light that the nights would be a lot brighter than here, but still thousands of times dimmer than daylight.

illiontor wrote:Jimi Hendrix? I thought that was Timothy Leary. Oh well...

Leary played a guitar?

aristarchusinexile wrote:Leary played a guitar?

Jimi was right handed ???

Chris Peterson wrote: There would be enough light that the nights would be a lot brighter than here, but still thousands of times dimmer than daylight.

It's amazing how bright our planet's cloudless, and even moonless, nights are in natural areas where our sight can sensitize itself. No need for flashlights at all.

bystander wrote:

aristarchusinexile wrote:Leary played a guitar?

Jimi was right handed ???

So you see it too!?!? It's not my imagination?!?! Space really does rock!??! And you're absolutely right .. the player IS right handed!! I love you, Man! Where can we get tickets, or do we go over the fence?

aristarchusinexile wrote:So you see it too!?!? It's not my imagination?!?! Space really does rock!??! And you're absolutely right .. the player IS right handed!! I love you, Man! Where can we get tickets, or do we go over the fence?

Think I'll wait this one out. Not sure I'm ready to get into that concert just yet.

aristarchusinexile wrote:It's amazing how bright our planet's cloudless, and even moonless, nights are in natural areas where our sight can sensitize itself. No need for flashlights at all.

Which is all the more apparent when there are thick clouds. Then it is truly dark, and you can appreciate just how much light comes from skyglow, and to a lesser extent starlight and the Milky Way.

Chris Peterson wrote:

aristarchusinexile wrote:It's amazing how bright our planet's cloudless, and even moonless, nights are in natural areas where our sight can sensitize itself. No need for flashlights at all.

Which is all the more apparent when there are thick clouds. Then it is truly dark, and you can appreciate just how much light comes from skyglow, and to a lesser extent starlight and the Milky Way.

Truly dark - like on Prince Edward Island I couldn't see my hand held in front of my face.