Gecko23 wrote:I really liked this one. Andromeda is an absolutely beautiful galaxy, and it was nice to be able to compare it in visible and ultraviolet. You can see so many details in UV!
Here's something that I found on the UV image that didn't appear in the visible. The image I cropped below includes the bright star at the lower right of the image. What could these three circles be?
^^^^^^^^
My first inclination was to think them photographic artifacts, eg lens flares.
I too had noticed that region, actually, while wondering about something else -- what appears to be flare around the brighter object nearby is unsettlingly off-center of what one might expect. After your post, I decided to take a closer look.
First, in SkyTools I identified the bright central object as star HD 3914 / HIP 3293. After taking an angular measure to the nearest stars to it for alignment & ID purposes, I pulled up a 4' plot around HD 3914 in SIMBAD.
After orienting my chart with the APOD images via those 4 very faint stars in the region (roughly) SW of HD 3914, I determined they were (from north-to-south) Pul -3 50211, & 2MASS #s J00421007+4040086, J00420301+4039430, & J00420303+4038418. Pulling up a 4' plot in SIMBAD, the
only thing between those 4 stars & HD 3914 - the position of your 3 'circles' - was a
single object: Bol 65, a Globular Cluster, at coords 00 42 01.91 +40 40 13.0 [J2K].
A single object : 3 'circles'. Hmmmm. Unless SIMBAD's plot doesn't include all actual objects in that area, intriguing indeed.
Anybody got anything more conclusive?
+++
The whole UV Andromeda is astonishing in what it reveals. I have literally sat here for hours 'flipping' back & forth between the two images. So MANY items of interest, especially in seeing how objects so very bright in the visible spectrum seem to almost disappear in UV, & vice versa - as well as how bright they are in UV while so exceedingly dim & barely detectable in visible light. And
also vice versa! You might expect most of the brighter objects to proportionatly emit more UV light - same in
either spectrum for that matter, but that's clearly not the case as a trend.
Another thing I find fascinating is how much structure shows up in UV that appears almost completely absent in visible. One would expect a far more even disbursement of UV sources - plenty of them, sure, but more evenly spread, randomly across the image. Making me wonder, why so much 'clumping' of UV sources? What makes one particular region so conducive to 'hosting' a heavy majority of UV emitting objects, than another? Or more basically, what 'put' them there, to start with? I can't see it as being just chance alignment.
Truly wondering,
~S*H
[quote="Gecko23"]I really liked this one. Andromeda is an absolutely beautiful galaxy, and it was nice to be able to compare it in visible and ultraviolet. You can see so many details in UV!
Here's something that I found on the UV image that didn't appear in the visible. The image I cropped below includes the bright star at the lower right of the image. What could these three circles be?
[url=http://imagesocket.com/view/Swift_M31_large_UV70pdc4.png][img]http://content.imagesocket.com/images/Swift_M31_large_UV70pdc4.png[/img][/url][/quote]
^^^^^^^^
My first inclination was to think them photographic artifacts, eg lens flares.
I too had noticed that region, actually, while wondering about something else -- what appears to be flare around the brighter object nearby is unsettlingly off-center of what one might expect. After your post, I decided to take a closer look.
First, in SkyTools I identified the bright central object as star HD 3914 / HIP 3293. After taking an angular measure to the nearest stars to it for alignment & ID purposes, I pulled up a 4' plot around HD 3914 in SIMBAD.
After orienting my chart with the APOD images via those 4 very faint stars in the region (roughly) SW of HD 3914, I determined they were (from north-to-south) Pul -3 50211, & 2MASS #s J00421007+4040086, J00420301+4039430, & J00420303+4038418. Pulling up a 4' plot in SIMBAD, the [i][u]only[/u][/i] thing between those 4 stars & HD 3914 - the position of your 3 'circles' - was a [u]single[/u] object: Bol 65, a Globular Cluster, at coords 00 42 01.91 +40 40 13.0 [J2K].
A single object : 3 'circles'. Hmmmm. Unless SIMBAD's plot doesn't include all actual objects in that area, intriguing indeed.
Anybody got anything more conclusive?
+++
The whole UV Andromeda is astonishing in what it reveals. I have literally sat here for hours 'flipping' back & forth between the two images. So MANY items of interest, especially in seeing how objects so very bright in the visible spectrum seem to almost disappear in UV, & vice versa - as well as how bright they are in UV while so exceedingly dim & barely detectable in visible light. And [i]also[/i] vice versa! You might expect most of the brighter objects to proportionatly emit more UV light - same in [i]either[/i] spectrum for that matter, but that's clearly not the case as a trend.
Another thing I find fascinating is how much structure shows up in UV that appears almost completely absent in visible. One would expect a far more even disbursement of UV sources - plenty of them, sure, but more evenly spread, randomly across the image. Making me wonder, why so much 'clumping' of UV sources? What makes one particular region so conducive to 'hosting' a heavy majority of UV emitting objects, than another? Or more basically, what 'put' them there, to start with? I can't see it as being just chance alignment.
Truly wondering,
~S*H