A discovery at long last?

User avatar
Pete
Astro Day Coordinator
Posts: 3819
Joined: Fri Jun 13, 2003 9:03 pm

A discovery at long last?

Unread post by Pete »

Monday, 22 Oct 2012

It’s been beautiful weather today and although the Clear Sky Chart hasn’t updated since 03:00 all forecasts suggest a cloudless sky with decent transparency. An ASSNE observing invitation was issued early in the morning in anticipation of a good night out, and the MPC downloads are processed and planning started before noon. Air temp at start of imaging is 57°F

329338 is a 1.0 km sized Apollo now 10 million miles out and 17.3 magnitude. Ephemeris uncertainty level is 1, RMS residual is 0.51. Asteroid was last observed 10 May 2012, and this is on the MPC critical object list just a check to see if there’s been a change due to gravitational perturbation. Imaged from 18:47 – 19:01 hrs at 30 sec exposure, 2X2 binning, -19°C cooling. Got it cleanly in single frames. Frames 1, 7 &11 show dRA = -0.1’ and dDEC = +1.5’ Yikes! That’s a pretty major variation.

138893 is a 1.7 km Apollo now .43 AU distant and 19.0 magnitude. Imaged starting at 19:23 hrs, movement is a fast 6.8’/hr and attempting to stack 30 second images doesn’t work – perhaps because the asteroid is relatively low and this far down the sky stars are “mushy” even after refocus. Gave it up at 19:43 when even stacking 7 deep doesn’t work.

163732 is a 5.5 km sized Apollo now 1 AU distant and 17.5 mag. Uncertainty is 1 and motion is 2.6’/hr. Imaged from 19:57 – 20:14 hrs. Frames 1-3, 4-6 & 7-9 show dRA = -.1’ and dDEC = 0.

2012 UU27 is a 1.6 km sized asteroid discovered only 4 days ago. It’s .7 AU distant and a dim 19.4 magnitude. Uncertainty level is 8 out of a possible 9, and motion is 3.1’/hr Imaged from 21:18 – 21:44 hrs at 2 min, 2X2, -20C, 2 Hz. Frames 1-3, 4-6 & 7-9 show dRA = +0.2’ and dDEC = +0.1’.

Air temp is down to 51F. There’s been very little dew and the sky is transparent – almost as good as winter.

162911 is a 1.0 km sized Apollo now 18.1 magnitude and .25 AU distant. Uncertainty level is 2 and RMS residual is 0.47 Imaged from 20:21 – 21:00 hrs at 2 min, 2X2, -20C, 2 Hz. This one’s high and the image is much sharper. The asteroid appears nice and bright in single frames. Frames 1, 7 & 14 show dRA = +0.3’ and dDEC = +0.4’


2012 TY79 is a 690 meter sized 19.6 magnitude asteroid discovered 13 days ago. It’s .43AU distant, apparent motion is 2.1’/hr, uncertainty level is 6. This is intended to be my challenge object tonight. Imaging started at 21:53 hrs at 2 min, 2X2, -20C, 2 Hz. Short stacks don’t seem to be very good so eventually, playing with stacking as more and more images collect, frames 1-5, 6-10 & 11-15 show dRA = +0.5’ and dDEC = +0.1’ Half an hour total exposure is still very fast for something this faint. S/N and FWHM are 3.9/6.2, 6.0/5.2 & 5.5/4.3 respectively.

2001 OG83 is an 18.8 mag asteroid in the frames used for 2012 TY79. It’s moving at a slow .53’/hr and I’ve collected more frames while working on TY79. Stacking, frames 1-5, 8-12 & 16-20 show dRA = +0.1 and dDEC = 0. OG83 isn’t on the critical list but if ya got it ya work it.

2008 ON12 also shows up on the Guide 9 software as being in the 2012 TY79 frame. And ON12 is also listed as being 19.6 magnitude, 1.7 km in size & .9 AU distant. Movement is a slow .5509’/hr at position angle 253.0 Since the camera keeps recording until I’ve fully worked a FOV, I’ve collected a lot of images since 21:53 hrs. And with blinking 5 frame stacks I can see what appears to be an asteroid moving quite slowly and out of position. Only after looking more closely at my Guide 9 software data printout do I discover that 2008 ON12 appears to have been lost! It was discovered in Aug 2008 and observed for only 5 days, so now the uncertainty level isn’t even documented. What am I viewing? I’m running track & stack using the motion predicted for 2008 OG83, but Astrometrica suggests that this could also be 2010 OW55 – another lost asteroid. Or, since both are around 7 arc-minutes out of position, this could be my first discovery. I keep going for 2 hours in an attempt to get a handle on the ephemeris should it be a discovery. I’m now in the SE, so this object will be up all night, but no way can I stay up or even get up to catch it near dawn. To qualify as a discovery, one must get 2 separate nights of observations in, and tomorrow night’s forecast to be cloudy. Here’s the results of the observations with deviations from 2008 ON12’s position:
Stack dRA dDEC S/N FWHM red magnitude
1-9 +5.9’ -1.7’ 6.8 4.0 20.2
18-24 +5.9’ -1.7’ 6.0 4.3 19.9
43-55 +5.9’ -1.6’ 4.1 3.1 20.7
56-64 +5.9’ -1.6’ 6.0 3.8 20.4
THIS IS EITHER A REAQUISITION OFA LOST ASTEROID OR A DISCOVERY OF A NEW ASTEROID.

This is the latest I’ve been out in the past 2 years. Tired. In at 00:20 hrs after pausing outside the dome to admire Jupiter and the Pleiades. Not knowing what to do with it, and knowing the limitations of it being a “one nighter”, I simply emailed MPC the data at 00:30 hrs with the 18 other observations for the night, only without identifying the asteroid. Hopefully they’ll figure it out.

I’ve really got to figure out how to better handle discovery procedure at the MPC.

hgp logged 20:30 hrs, 23 Oct 2012 Haven’t even documented my observations from Saturday night (Oct 20) yet, but want to get this all down while it’s clear in my mind.
Pete P.
User avatar
BobSikes
15+ Years Member
Posts: 426
Joined: Sat Jun 14, 2003 12:57 pm

Re: A discovery at long last?

Unread post by BobSikes »

Good going Pete,

Hope you will be able to get another data point and bag a new one

BobS
User avatar
Pete
Astro Day Coordinator
Posts: 3819
Joined: Fri Jun 13, 2003 9:03 pm

Re: A discovery at long last?

Unread post by Pete »

Thanks Bob,

I was out this morning a bit after midnight after it had clered, and the cloud rolled in as I was doing the fine focus. Out again at 04:30, started imaging at 5, and the area where 2008 ON12 should be was too low to work well, with the seeing falling apart severely over an hour & twenty minutes of imaging. Again no joy. If it's new I've undoubtedly lost it by now as my 2-hour track was very short. And if it's a recovery there's no glory there. Now that I'm completely wiped from little sleep tonight's forecast is for a great sky :evil:

What a hobby!

Pete
Pete P.
User avatar
AndyG
Network Admin
Posts: 1160
Joined: Wed Nov 30, 2011 10:18 pm

Re: A discovery at long last?

Unread post by AndyG »

So, Pete, did you get a chance to confirm it tonight? The seeing tonight is by far the best I have seen in many months.
Andy
User avatar
Mark G
15+ Years Member
Posts: 3069
Joined: Fri Jun 13, 2003 6:57 pm

Re: A discovery at long last?

Unread post by Mark G »

Any more news Pete :?:
Clear skies,

Mark

iOptron CEM25P w/ Tri-pier
CGEM DX
LXD750 w/ CDS #1697
LXD75 w/ #497 autostar Hypertuned
Antares 8" f/5 Newt
Antares 4" f/15 "Vixen Spec" long focus refractor
Orion 4" f/7 ED refractor
Astro-Tech 65mm Quad APO
and so much more
User avatar
Pete
Astro Day Coordinator
Posts: 3819
Joined: Fri Jun 13, 2003 9:03 pm

Re: A discovery at long last?

Unread post by Pete »

Guess I lost it. Never got a response to my query to the MPC. And at 20th magnitude this was very much at the edge of my capability with excellent conditions.

P
Pete P.
Locked