Re: APOD: IRAS 20324: Evaporating Protostar (2013 Sep 04)
Posted: Thu Sep 05, 2013 11:36 am
It's now Sept 5 and today's APOD isn't up. I hope everyone's ok.
APOD and General Astronomy Discussion Forum
https://asterisk.apod.com/
Everything is indeed fine.nstahl wrote:It's now Sept 5 and today's APOD isn't up. I hope everyone's ok.
Clicking on the link "above image" in the description, brings up a write-up that includes this: "Spectroscopic observations of the central star within IRAS 20324+4057..." And just looking at it, the dust in the 'head' of the cloud appears to be lit up in three places.Chris Peterson wrote:How are you determining that?FLPhotoCatcher wrote:There is at least one (maybe three or four) stars inside the right side of the cloud.
Which could be caused by a single source of illumination, no?FLPhotoCatcher wrote:Clicking on the link "above image" in the description, brings up a write-up that includes this: "Spectroscopic observations of the central star within IRAS 20324+4057..." And just looking at it, the dust in the 'head' of the cloud appears to be lit up in three places.Chris Peterson wrote:How are you determining that?FLPhotoCatcher wrote:There is at least one (maybe three or four) stars inside the right side of the cloud.
I'd call that weak evidence for the location of other stars.FLPhotoCatcher wrote:Clicking on the link "above image" in the description, brings up a write-up that includes this: "Spectroscopic observations of the central star within IRAS 20324+4057..." And just looking at it, the dust in the 'head' of the cloud appears to be lit up in three places.Chris Peterson wrote:How are you determining that?FLPhotoCatcher wrote:There is at least one (maybe three or four) stars inside the right side of the cloud.
I was looking at it the other day after reading the posts in this thread. The red channel for the image uses the F814W filter which should see through some of the dust but it's still pretty hard to tell what is going on. To me it looks like the brightest clump in the lower left might be the protostar while the two lesser ones up and to the right of it just reflecting the light from the protostar. The do like three separate areas of coalescence, though.Chris Peterson wrote: I'd call that weak evidence for the location of other stars.
It is extremely difficult in most cases to determine where stars are actually located in a single optical image. Those stars may be inside the dust, or they may be in front of it or behind it. Spectroscopy might be able to answer that question, but I don't think this image alone can.