Red Barn Observatory MPC/IAU H68

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Discovery of Asteroid 2008 UM91

Date: 20081026

Tonight while imaging a normal search area - in hopes to pick up asteroid C1926 I noticed another very faint object in the field that was not identified by using the "known object overlay" in Astrometrica.  C1926 was found near the edge of the field and luckily the unknown object was nearly "dead center" - making it easy to measure.  This was the last field of the night, so I went ahead and measured C1926 and the unknown object which I assigned a temporary designation RBO0001.  Shortly after measuring the two, I submitted the observations to the MPC - in which RBO0001 was submitted as a "one nighter".  I knew that the MPC requires unknown objects to be measured at least two nights to be considered real, but I also knew that the survey telescopes were working in this same area.  In hopes to beat them to this potentially new object, I went ahead and submitted the positions.  See the discovery field and measurements below.

Later on that day, I sent John Sachs http://www.fotozz.com/ the data on the object and shortly later he gave me a call on the telephone.  I was still unsure if this was a new object or not, but he was determined it was.  We talked for a while and decided that a second night would be needed to be sure.

COD H68
CON S. Farmer Jr., 865 WB Parks Road Ty Ty, Georgia USA 31795 [sefarmer@cometary.net]
OBS S. Farmer Jr.
MEA S. Farmer Jr.
TEL 0.30-m f/5 Cassegrain + CCD
ACK MPCReport file updated 2008.10.26 06:26:28
AC2 sefarmer@cometary.net
NET USNO-B1.0
RBO0001    C2008 10 26.34095 02 38 50.80 +04 42 49.8          20.3 V      H68
RBO0001    C2008 10 26.34842 02 38 50.43 +04 42 46.7          20.2 V      H68
RBO0001    C2008 10 26.36327 02 38 49.66 +04 42 38.4          20.0 V      H68
RBO0001    C2008 10 26.37070 02 38 49.25 +04 42 33.7          20.2 V      H68
CK08S030  C2008 10 26.39169 04 30 29.18 +18 16 32.6                            H68
CK08S030  C2008 10 26.39749 04 30 28.91 +18 16 32.8                            H68
CK08S030  C2008 10 26.40333 04 30 28.66 +18 16 31.6                            H68
0C1926        C2008 10 26.34095 02 38 25.98 +04 43 25.3          19.8 V      H68
0C1926        C2008 10 26.35583 02 38 25.33 +04 43 22.5          20.2 V      H68
0C1926        C2008 10 26.37070 02 38 24.57 +04 43 18.1          20.0 V      H68
----- end -----
 

Date: 20081028

My goal for tonight was to follow-up on the unknown object that I detected on the 26th.  Using Find_Orb, I was able to generate an ephemeris of the object.  After powering up the scope and camera, I slewed the scope to the predicted area and began taking pictures.  I wanted to get at least an hour on this object, so using CCDSoft, I set it to take 60 - 1 minute exposures of the area.  After about 15 minutes, I used Astrometrica to begin searching the field to see if the target was in the field of view.  I created three images each composed of five - one minute exposures - stacked accordingly to the predicted motion and P.A. of the object.  Once I completed the stacking, I used the blinking option in Astrometrica - and there it was.  It wasn't dead center in the field, but it was in the field good enough to get a second night of observations on it.  Since it was about 2 hours before daylight and I had to go to work in about three hours, I decided to go ahead and measure the object and get a couple hours sleep.  To link the positions from tonight with the positions from the 26th, I labeled the object RBO0001.  See the follow-up image and positions below.

COD H68
CON S. Farmer Jr., 865 WB Parks Road Ty Ty, Georgia USA 31795
OBS S. Farmer Jr.
MEA S. Farmer Jr.
TEL 0.30-m f/5 Cassegrain + CCD
ACK MPCReport file updated 2008.10.28 05:02:21
NET USNO-B1.0
     RBO0001  C2008 10 28.32725 02 37 07.38 +04 26 45.9          19.8 V      H68
     RBO0001  C2008 10 28.33552 02 37 06.97 +04 26 42.3          19.4 V      H68
     RBO0001  C2008 10 28.34380 02 37 06.48 +04 26 38.3          19.1 V      H68
     RBO0001  C2008 10 28.36871 02 37 05.27 +04 26 28.8                           H68
----- end -----
 

Date: 20081029

After submitting the second set of data on the 28th, all I could do then was wait for a designation from the Minor Planet Center.  On 20081029, I received an e-mail that only contained RBO0001 K08UM91.  I knew that meant that it was a new asteroid but I wasn't sure whether or not I was the discoverer.  Later on, I found out that if it were a known object, it would have appeared as (K08UM91 - noting the * ( *.  Apparently, I was the first to submit observations of this object.  Using the Minor Planet Center Ephemeris Service, I wanted to see if it would generate a list of all observations that have been submitted of this object.  Due to the fact that only a few observations had been submitted, it did not list them and a third night would be needed.

Date: 20081104

Several days went by and I was unable to follow-up and image this object on a third night due to clouds and poor sky conditions.  Meanwhile, I had been in contact with Juergen Linder (Corner Observatory B50) - a fellow asteroid and comet hunter in Germany http://www.cometmillenium.de/  His sky conditions were also poor at the time but he was able to contact Rolf Apitzsch (Observatory Wildberg 198) - who also lives in Germany - http://www.astro-wildberg.de/ in hopes that he could produce a third nights observations on this object.  Using a remote observatory in New Mexico (Tzec Maun Observatory H10) Rolf was able to find 2008 UM91 and successfully produce a third night of observations.

Date: 20081105

Rolf submitted his observations to the MPC on 20081105 and now all we could do was wait for the data to be processed through the Minor Planet Centers computers.  We would know something once the next MPEC was issued.  Rolf's observations are below.

Date: 20081106

Checking the latest MPEC this morning, it had K08U91M listed as a new discovery.  http://www.cfa.harvard.edu/mpec/K08/K08V32.html  Rolf's additional observations provided enough data to generate an orbit - adding this object to the list of new asteroids discovered.  When I checked the Minor Planet Ephemeris Service again, it provided orbital elements as well as a list of all observations that had been submitted on this object.  I also noted that Mt. Lemmon Survey also picked this object up on the same night I produced the second set of observations.  Luckily enough, I beat them to it by two nights!  See Minor Planet Ephemeris Service information below.

2008 UM91

Display all designations for this object

Epoch 2008 Oct. 21.0 TT = JDT 2454760.5                 MPC
M 355.23586              (2000.0)            P               Q
n   0.26069098     Peri.  228.51313     +0.75897111     -0.65082350             T = 2454778.77506 JDT
a   2.4269009      Node   172.01975     +0.63178154     +0.72873144             q =     2.2447930
e   0.0750372      Incl.    8.19499     +0.15752756     +0.21302409
P   3.78           H   17.0           G   0.15
From 15 observations 2008 Oct. 26-Nov. 4.
  
Residuals
20081026 *H68  1.0+  2.4+    20081028  G96  0.7-  1.0-    20081104  H10  0.1+  0.1+
20081026  H68  1.5+  3.0+    20081028  H68  0.7-  0.5-    20081104  H10  0.3+  0.0+
20081026  H68  1.9+  2.0+    20081028  G96  0.4-  1.0-    20081104  H10  0.2+  0.2+
20081026  H68  1.6+  0.9+    20081028  H68  1.3-  0.5-    20081104  H10  0.1+  0.2+
20081028  H68  1.3-  0.8-    20081028  G96  0.5-  0.9-    20081104  H10  0.2+  0.2+
20081028  G96  0.6-  1.0-    20081028  H68  0.9+  1.9+

Rolf was able to send me some images he took using the remote observatory in New Mexico and I have one of those listed below showing 2008 UM91.

It was nice working with people all over the world - chasing this somewhat small asteroid through the sky - but that is what we do.  Thanks to the Internet, we are able to contact each other when we need help with follow-up observations or other informative help - and many are more than willing to take the time to provide whatever help is needed. 

It's hard for amateur astronomers to discover new asteroids and comets with the competition from the funded programs, but it is not possible for the amateur astronomers to produce the huge amount of data (and protection) from Near Earth Objects and other Potentially Hazardous Objects that the funded programs produce.  But we can try...

I've listed a couple links where help can be found if needed.

 http://de.groups.yahoo.com/group/SBSS-comets/

 http://tech.groups.yahoo.com/group/Asteroid_Hunters/

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Copyright © 2008 The Cometary Space Web of Steve E. Farmer Jr.

Last modified 08/31/2010 02:35 PM -0700

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