Affiliation
American Association of Variable Star Observers (AAVSO)
Sat, 01/26/2013 - 05:20
Hello everyone,
I am a new user here and just trying to get everything to work correctly. I was able to upload some images, but it turns out that I did not capture the variable star I intended (R PER). However, when I was examining the images, I noticed a "moving star" that assume may be a comet or asteroid. I searched NASA's Small body identification system (http://ssd.jpl.nasa.gov/sbfind.cgi) but nothing was showing up nearby. Can someone please help me figure out what I'm looking at here?
Thanks,
Blake
Hi Blake,
It is rare for the normal amateur to discover a new asteroid or comet with a small telescope, as most of the ones brighter than about 20th are well-known. My guess is that: you didn't set your constraints properly, such as using too bright a magnitude limit (the magnitudes are really unknown; it is easier to set the limit to 30.0 or something just to see everything in your field); you were seeing a satellite, such as a geosynchronous bird; or your coordinates/time are off.
That said, seeing a new wandering object in your field is always fun. I've seen them often in the autoguider images at USNO-Flagstaff (where the entire field is shown, not just a cutout around the guide star), along with meteors.
Arne
I know that
Thanks, Arne.
I know that the possibility of it being a new object are quite slim. I just was curious if/how I could determine what it actually is. A simple google search led me to NASA's small body database. I hadn't considered satellites; are those included in the database also? Also, is that the "best" database to use?
I have observed geostat satellites several times in the southern sky, as seen from my home here at 39N. They will appear as stars at around mag 8 or so, perhaps as a glint off the satellite, and I'm sure they are visible all the time at much dimmer mags. Generally they are spotted around the declination of Leo or Virgo and a gold color is apparent. Even if they are not drifting at all they would trail as the Earth turns! I have never been able to identify one due to the large number of them and the fact that you'd have to get it down to a fraction of a degree to really be able to sort it out. GW
Another possibility is a Molniya satellite. See:
http://en.wikipedia.org/wiki/Molniya_orbit
I don't do satellite-tracking myself, so I can't point you to modern resources to figure out if this is what you found or not, but I know that such resources exist.
Why not post an image?
Cheers,
Doug
I'm away from my home computer right now, so I don't have access to all of the images. However, I did log on to VPhot and take a screen shot of this image that I uploaded which is a stack of 10, 10 second exposures. I highlighted the object in question. It did appear as a distinct sphere in each individual image.
Thanks,
Blake
If the highlight is near the top of the frame, what I see is a row of hot pixels caused by the stacking of the frames with slight offsets between them. The single hot pixel in that area shows up as a string because the stacking aligns on the stars. There are similar rows elsewhere in the frame.
Maybe I'm not looking at the correct objects?
...Tim (HTY)
Here is another link for finding whether a known minor planet is crossing your field of view:
http://www.rotse.net/temp/CheckMP2.html
The one I used to access all of the time, which was on the Harvard CBAT site, seems to be gone these days. However, the one that you used at the NASA Small Bodies site, and this one with the ROTSE group, look equivalent.
I must be missing something, Blake, as the png you uploaded does not have anything highlighted on my screen. I also don't quite know what you mean about the object appearing spherical. What is the field of view of your image, and what direction is north and east?
Arne
Yes, you are looking at the right thing. I get it now. When I was looking at the original images, those other hot pixels were very faint and I didn't notice them, but that one at top left was much bigger and brighter. Thanks for your help; I'm learning this slowly.
You should never let something go when it isn't right for you. I always try to figure out any little transient. Too bad, I usually can't positively identify these little lights, and I have to resort to "satellites," which is most likely correct, of course. But it is good to never let some anomalous thing drop until you have resolved it to your own satisfaction. You just never know for sure what you might turn up. With a little practice, most artifacts will become more apparent to you but little objects will still show up from time to time. I remember one time in 2009 when I saw three of the golden stars, apparently geostationary satellites, glint at me within 15 minutes and within a few degrees of each other, while I was visually observing variables in Leo with a 10" telescope. It's really pretty strange when you spot something that doesn't belong, only to have it fade before your eyes, and apparently reappear a few minutes later in a new spot. GW