2012 LZ1 - a big chunk of rock
Finally on Sunday, June 17, 2012, after a long period of unstable weather, I loaded my target list of minor planet followup observations for an unattended imaging run. The list contained two recently discovered NEOS: 2012 LD1 and 2012 LT7, PHA 2004 CL which was only seen for two nights in that opposition at that time, NEO 2012 BC20 deep in a crowded milkyway starfield, and numbered NEO (317685). The run was supposed to start at 21:30 UT. I was a little ahead of time. Flatfield and bias images ready, initial focus done. At 21:05 UT it was not dark enough for those faint objects. So I decided to take a shot on PHA 2012 LZ1 which was discovered on June 10 and passed the earth on June 14 in 14.5 LD (lunar distances). Only a couple of days after closest encounter this object was fairly bright with a magnitude of 15.0 but still pretty fast with an angular speed of about 30 arcseconds per minute. With an exposure time of 3-5 seconds it sould be possible to make it visible on a single exposure but preventing the object from trailing. The pointing of the telescope was a matter of a minute and a sequence of 80 images was taken from 21:15 - 21:24 UT.
First the size of 2012 LZ1 was thought to be around 500 meters according to its brightness and distance. Because of its size and proximity to the earth this object was selected as radar target for the famous Arecibo radio telescope in Puerto Rico and the results where a bit surprising: 2012 LZ1 is almost twice as big. Scientists where able to determine that this space rock was only reflecting 2-4 percent of the sunlight that hit its surface. A surface as dark as coal.
Bright summer comet 2010
C/2009 R1 McNaught is currently the brightest comet in the summer sky. After a long break due to bad weather we finally managed to catch this object in the morning dawn of June 5 in the low northeastern sky.
During this 20 minute exposure the last quarter moon was also already well above the horizon. Currently C/2009 R1 reaches magnitude 6 and is a nice object for binoculars. If predictions are true he could get as bright as magnitude 3-4 but observations with the naked eye will be difficult because of its low altitude.
The best observing conditions will arise in the following two weeks till mid June. Mc Naught reaches its closest approach to earth on June 15. After June 22 the moon will again interfere and the angular distance to the sun is further decreasing.
The image presents a nice long plasma tail and a shorter dust tail. The plasma tail is in fact much longer. Our 14" with a focal length of 2.100 mm show only a small piece of 25 x 16 arcminutes. After the image we inspected to comet visually through the 14 inch telescope. The tail was not visible but the coma bright, round and approx. 5' in diameter.
Rob McNaught discovered the comet on September 9 with the 0.5 Uppsala Schmidt Telescope of the Siding Spring Observatory at a magnitude of 18. Siding Spring is also involved in continuous asteroid surveys.
Comet C/2009 K5 (McNaught)
April 17 was a beautiful day with absolutely no clouds. The daytime sky was blue maybe a little haze was noticeable but not realy sure if that was caused by the volcanic ash coming from islandic volcano Eyjafjallajoküll.
Comet P/2010 H2
Comet P/2010 H2 is a somewhat mysterious object. It first appeared on the NEOCP on April 16 as an unusually bright 12 mag discovery with the preliminary designation 04F0011 submitted by the Crni Vrh Observatory. Soon a discussion emerged about the nature of this object on the MPML. Because it could not be found on previous images of the big surveys it was proposed that it might be a comet outburst.
Comet P/2010 H2 developing
A few days after its discovery Comet P/2010 H2 (Vales) is further developing its appearance to a "real" comet. The former asteroidal NEOCP object 04F0011 now shows a nice 2' size coma.