Starship Asterisk*

IRAS 20324: Evaporating Protostar

Explanation: Will this caterpillar-shaped interstellar cloud one day evolve into a butterfly-shaped nebula? No one is sure. What is sure is that IRAS 20324+4057, on the inside, is contracting to form a new star. On the outside, however, energetic winds are blowing and energetic light is eroding away much of the gas and dust that might have been used to form the star. Therefore, no one is sure what mass the resulting star will have, and, therefore, no one knows the fate of this star. Were the winds and light to whittle the protostar down near the mass of the Sun, the outer atmosphere of this new star may one day expand into a planetary nebula, possibly even one that looks like a butterfly. Alternatively, if the stellar cocoon retains enough mass, a massive star will form that will one day explode in a supernova. The eroding protostellar nebula IRAS 20324+4057 spans about one light year and lies about 4,500 light years away toward the constellation of the Swan (Cygnus). The above image of IRAS 20324+4057 was taken with the Hubble Space Telescope in 2006 but released last week. The battle between gravity and light will likely take over 100,000 years to play out, but clever observations and deductions may yet yield telling clues well before that.

<< Previous APOD

This Day in APOD

Next APOD >>

[/b]

I am surprised to see that it is not called sperm nebula

Why do they say that "IRAS 20324+4057, on the inside, is contracting to form a new star"? There is at least one (maybe three or four) stars inside the right side of the cloud. Wouldn't these stars themselves sweep away much of the dust, thus possibly preventing any new stars from forming?

Also, why was this image released seven years after it was taken, and not sooner?

FLPhotoCatcher wrote:Also, why was this image released seven years after it was taken, and not sooner?

Hubble takes a lot of pictures. Sometimes they just get buried.

It is the "Star Child" from "2001: A Space Odyssey"

Very interesting image...HAPPY BIRTHDAY!!!! Well...someday...

:---[===] *

Why are the gases blowing in the direction they are? What is causing the wind? Is there something else going on out to the "right" of where the protostar is?

With the references to a possible Butterfly Nebula I would have thought it is the Caterpillar Nebula

bystander wrote: http://asterisk.apod.com/viewtopic.php?t=32010

That link bystander provided is fascinating too. From it I copy this:

This light-year-long knot of interstellar gas and dust resembles a caterpillar on its way to a feast. But the meat of the story is not only what this cosmic caterpillar eats for lunch, but also what's eating it. Harsh winds from extremely bright stars are blasting ultraviolet radiation at this "wanna-be" star and sculpting the gas and dust into its long shape.

The culprits are 65 of the hottest, brightest known stars, classified as O-type stars, located 15 light-years away from the knot, towards the right edge of the image. These stars, along with 500 less bright, but still highly luminous B-type stars make up what is called the Cygnus OB2 association. Collectively, the association is thought to have a mass more than 30,000 times that of our Sun.

So it’s the gang of 65 O and 500 B stars in the neighbourhood off camera to the right that are emitting the radiation that’s blowing the gas and dust away from this nebula. I found the fact that there are 65 O stars in its vicinity to be amazing, since main sequence O stars are so rare. Wikipedia says that O stars make up only 0.00003 % of all stars, which is good because they are all destined to go supernova at some point. I’m also glad that this object and more importantly the rowdy gang of 65 are 4,500 light years away!

BDanielMayfield wrote: So it’s the gang of 65 O and 500 B stars in the neighbourhood off camera to the right that are emitting the radiation that’s blowing the gas and dust away from this nebula. I found the fact that there are 65 O stars in its vicinity to be amazing, since main sequence O stars are so rare. Wikipedia says that O stars make up only 0.00003 % of all stars, which is good because they are all destined to go supernova at some point. I’m also glad that this object and more importantly the rowdy gang of 65 are 4,500 light years away!

65 destined Super Novas in the same area Geeze When they're ready, one will probably set all the others off and create one Big Supreme Nova, that will light up our night sky

FLPhotoCatcher wrote:There is at least one (maybe three or four) stars inside the right side of the cloud.

How are you determining that?

Looks to me like a Cosmic Mud Puppy

As interesting as today's APOD is, and if there are seven more years of pictures yet to be released, we've got many treats ahead. Yesterdays APOD had a variety of beautifully colored stars very prominent in the photo. I'm curious why their diffraction spikes were eight as opposed to today's stars four?

It made the picture yesterday quite striking.

Ron-Astro Pharmacist wrote:As interesting as today's APOD is, and if there are seven more years of pictures yet to be released, we've got many treats ahead. Yesterdays APOD had a variety of beautifully colored stars very prominent in the photo. I'm curious why their diffraction spikes were eight as opposed to today's stars four?

Today's image is from Hubble which always has four. Scott used a telephoto Canon lens which produces eight spikes. Different instruments, different diffraction spikes. (I like that alliteration.) Those things can be very annoying if you are photographing a bright star. They get huge and ugly rather than small and pleasing.

Ron-Astro Pharmacist wrote:Yesterdays APOD had a variety of beautifully colored stars very prominent in the photo. I'm curious why their diffraction spikes were eight as opposed to today's stars four?

Today's image was made with the HST, which has a circular aperture obstructed by a secondary mirror supported by four vanes, which create the four diffraction spikes we see. Yesterdays image was made by an unobstructed aperture that wasn't circular, but had eight sides (determined by the type of iris in the camera lens). Thus the eight diffraction spikes.

FLPhotoCatcher wrote:Also, why was this image released seven years after it was taken, and not sooner?

Sometimes there can only be a public image release after the scientific study/paper has been published. The results of the study of this "tadpole" were published earlier last year: http://arxiv.org/abs/1201.2404

Sometimes an image can be published well before the results of the study have been published. An example is this Gemini image of the planetary nebula Sh2-71: http://www.gemini.edu/node/11815

starsurfer wrote:

FLPhotoCatcher wrote:Also, why was this image released seven years after it was taken, and not sooner?

Sometimes there can only be a public image release after the scientific study/paper has been published. The results of the study of this "tadpole" were published earlier last year: http://arxiv.org/abs/1201.2404

Sometimes an image can be published well before the results of the study have been published. An example is this Gemini image of the planetary nebula Sh2-71: http://www.gemini.edu/node/11815

Oh yeah, the "proprietary data" that litters the HLA which I'm not allowed to use but can't seem to exclude it from the results. There's a radio selection button for excluding it but it is flaky.

Stunning image - looks like a tadpole to us.

The Hubble site encourages folks to dig through the huge number of images to find interesting images. There aren't enough astronomers to even scratch the surface of the gazzillion images. The famous astronomer from the University of Arizona whose images frequenty grace the APOD site does just that. Except when he finds an interesting image in the Hubble database, he can add visual data from the telescopes to which he has access on Mount Lemmon (north of Tucson). He hosts public access to one of the telescopes on a regular basis so folks can explore and take images between oh-dark-thirty to midnight. (After midnight, that telescope is tasked with hunting for them pesky asteroids that ruin things for everyone.)
Sky Nights - http://skycenter.arizona.edu/

geckzilla wrote:Oh yeah, the "proprietary data" that litters the HLA which I'm not allowed to use but can't seem to exclude it from the results. There's a radio selection button for excluding it but it is flaky.

There shouldn't be anything older than a year. The initiator of an HST image can normally request a publishing embargo for up to a year to allow time to prepare a paper, but after that period the data becomes public.

It is unlikely that today's image wasn't previously available, it was simply lost in all the other data.

Chris Peterson wrote:There shouldn't be anything older than a year. The initiator of an HST image can normally request a publishing embargo for up to a year to allow time to prepare a paper, but after that period the data becomes public.

It is unlikely that today's image wasn't previously available, it was simply lost in all the other data.

I run into unavailable data almost every time I search that's more than a year old. I just found a tantalizing set for NGC 7008 a few moments ago from 2009. It's UVIS so it is probably blobby and not suitable for aesthetic purposes but the available WFPC2 data cuts off the usual half of the object with its familiar stealth bomber shape and makes me wonder how the whole thing looks. Anyway, the details aren't important, but it is very common for me to run into them. Maybe it is possible to access the data through DADS but I've never tried it because it doesn't look like something I should be touching.

geckzilla wrote:I run into unavailable data almost every time I search that's more than a year old.

Probably just missed. Anything that is NASA funded is in the public domain after the embargo. There may be slightly different rules where ESA is involved.

Chris Peterson wrote:

geckzilla wrote:I run into unavailable data almost every time I search that's more than a year old.

Probably just missed. Anything that is NASA funded is in the public domain after the embargo. There may be slightly different rules where ESA is involved.

Looking at it closer, I realize that what I thought was proprietary isn't proprietary. But I'm still blocked from downloading it in the same way as the proprietary data. I don't understand why. This has frustrated me for a long time and I haven't found out who to ask about it. Equally frustrating is the lack of preview image. I'm not sure I would even want the data but I can't tell for sure because there's no preview.

I'm not a trekkie but is not this, the "Dooms Day Machine" from the original Star Trek Series?