Viewing lots of asteroids but no turkeys airborn

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Viewing lots of asteroids but no turkeys airborn

Unread post by Pete » Fri Nov 29, 2013 1:57 pm

Thanksgiving eve sky starts out a little bit hazy but quickly clears for excellent viewing. Tired after the turkey and not intending to do much. And it’s cold. 27F.

251346 is a 2.7 km sized Apollo now .25 AU distant and a bright 15.9 magnitude. Uncertainty level is 1. Starting at 18:31, imaged at 3 min, 2X2, -30C, 2 Hz. The long exposures certainly aren’t necessary for this bright an object but it’s for sure that no new discoveries will be made blinking shallow 1 minute exposures. Frames 1, 6 &8 show dRA & dDEC = 0.0’

The chip’s frosting up at -30°C  There are a dozen small areas around the image edge that are blackened. I may be able to continue if it doesn’t get worse.

3200 Phaeton is a 7.9 km sized 16.8 mag Apollo now .9 AU distant. RMS residual is 0.50” Imaged from 19:26 – 19:42 hrs at 90 sec, 2X2, -30C, 5 Hz. The initial exposure is washed out. The dew shield’s mounted so it’s not reflections. I’d forgotten to shroud the camera against light leaks and this was quickly corrected. Frames 1, 4 & 7 show dRA and dDEC = 0.0’ and magnitude to measure 16.4 red.

Midway thru the Phaeton exposures I’d stepped into the house and ran the observatory using Windows Remote while warming up and putting on heavier clothing. The chip icing isn’t getting any worse and the night is getting better. Not feeling so tired now that things are going well and I’m warmed up. Scrap original plan to catch 2 asteroids and call it a night.

2006 HU30 is a 792 meter sized Apollo now .4 AU distant and a relatively dim 19.3 magnitude. Uncertainty level is 1. Ambient now down to 26°C. Imaged from 19:56 – 20:25 hrs at 3 min, 2X2, -30C, 2 Hz. The star images are very sharp. There’s no wind and I’m now seeing 5th magnitude sky. Temperature is holding steady and consequently so is focus. Individual 3 minute frames are usable but weak. Stacking 2X gives me a much better S/N of around 11. Frames 1-2, 4-5 & 6-7 show dRA & dDEC = 0.0’

2013 TB89 is a 2.1 km sized Amor now 17.7 mag and .4 AU distant. Discovered 31 days ago, uncertainty level is still 5. Imaged from 20:36 – 20:51 at 90 sec 2X2 -30C. Frames 1, 3 & 5 show dRA & dDEC = 0.0’ Object FWHM is a very tight 3.3 – 3.6

142781 is a 4 km sized Amor now 16.0 mag and .4 AU distant. Uncertainty level is 1. Relative motion is 3.9’/hr. Imaged from 21:39 – 21:51 hrs at 1 min, 2X2, -30C, 1 Hz. Frames 1, 3 & 5 show dRA & dDEC = 0.0’ and a red filter magnitude of 15.5.

2013 VD13 is a 1.8 km sized Amor now 18.6 mag and .5 Au distant. Discovered only 9 days ago the uncertainty level is 7. Apparent motion is 2.6’/hr. Air temperature’s down to 25F now but the warmer socks & boots are holding up. Imaged from 21:06 – 21:28 hrs at 2 min, 2X2, -30C, 3 Hz. Individual images are easily visible but stacking will result in a higher S/N and increased accuracy. Frames 1-2, 3-4 & 5-6 show dRA & dDEC = 0.0’

2013 SK19 is a 1.1 km sized Amor now 18.7 mag and .5 AU distant. With an orbital arc based upon 49 days of data, uncertainty level is 3. Motion is 1.9’/hr. At 22:04 hrs started imaging at 3 min, 2X2, -30C. Frames 1, 3 & 5 show dRA & dDEC = 0.0’

16029 is in the same frame of SK19 but not on the MPC critical object list. This 26 km sized main belt asteroid is 16.7 mag and moving slowly at 30”/hr. RMS is a surprisingly high 0.53” Imaging concluded at 22:37 hrs. Frames 1, 5 & 9 show dRA & dDEC = 0.0” with a magnitude of 17.0 R

2013 UR3 is a 2.5 km sized Amor now 16.9 mag and .4 AU distant. Discovered 18 days ago the uncertainty level is 5. Apparent motion is 3.1’/hr. Clouds are now racing in from the west and completion of this one is questionable. Imaged from 22:46 – 22:55 hrs at 90 sec, 2X2, -30C, 2 Hz. Frames 1, 2 & 4 show dRA & dDEC = 0.0’ with a magnitude of 16.2 R. Frame 5 was washed out by cloud.

That’s it. I’m cold & tired & well satiated with stargazing. Headed in at 23:00 only to catch the shutter closing cable around the scope, so when giving the cable a yank I pulled the telescope out of its parked position rather than closing the shutter. Spend another ½ hour unsuccessfully trying to realign the scope to the stars and due to complete overcast gave up the effort.

Conclusions & lessons learned:

Reminder to self: dry the camera desiccant plug.

Reminder to self: realign scope next partially cloudy night.

It was one of those rare perfect nights we get only 2 or 4 times a year :P

A record tying 27 observations were transmitted to the MPC at 23:45 hrs. Granted that most of tonight’s objects were bright, but I wanted to try for 20th magnitude and there just weren’t any interesting dim ones on the list of choices.

hgp logged 13:52 hrs, 29 Nov 13
Pete P.