Observing Report Comet C/2007 N3 (Lulin) 2009-1-31 12:45UT (1-31 05:45 MST)
I tried to find Coment Lulin from the Salt Lake City valley floor at 12UT (5MST). Light pollution backscatter into valley smog prevented acquisition. I drove to Little Mtn. Pass, arriving at 12:45UT (5:45MST). Temperatures were are around -3C; ZLM was about 4.6 (del CrB); NELM near target area in Libra was 4.5 (psi Oph) with noticeably lower transparency. On the eastern horizon at 20 deg alt, the Milky Way was visible from Cass in the northeast through Aql in the east east south. It was the end of astronomical twilight. The first hints of nautical twilight could be seen on the southeast horizon. Because of the weather, 8x35 (3 deg TFOV) and 20x70 binoculars (1 deg TFOV) were used. Comet Lulin is a fast moving object. On this night, it was located by traversing from Zuben Elakrab (38 Gam, 4v), the southeastern star of the Libra square to a chevron of three prominent stars. zet4 35 Lib (5v), zet3 34 Lib (6v) and zet1 32 Lib (5.6v). The comet was easily acquired 6 degs north west west of this chevron in the 8x35 binos. After dark adaptation, it was possible to more directly navigate to the target by direct acquisition of iot1 24 Lib (4.5v). 1.5 degrees north east of iot1 Lib is a triangular asterism consisting of HD135208 (a double est 6.5v combined), HD134812 (6.8v) and HD135230 (6.2v). Above the eastern side of that triangle were two fainter stars, HD135152 (SAO159115, 8.5v) and HD135125 (SAO159113, 9v), separated by 10 arcmins. These two stars where within a 1 deg TFOV of Comet Lulin. Lulin itself was very pleasing. It was about 8 arcmins in diameter with a slight central coma definition - DC2. No tail was apparent, but I understand imagers have captured one. It was reminiscent of the Dumbbell Nebula, M27. Using the in-out method, I estimated it around 7.7 mags +-0.5mags. It was brighter than HD134812 (6.8v) and dimmer than HD135152 (8.5v). Mars was bright and directly at the zenith and 2 magnitudes brighter than Spica. (Mars was not positioned for binocular observing.) Saturn was well positioned about 35 degs off the south western horizon and was 0.5 mags brighter than Spica. By 13:15UT (6:15am), nautical twilight was clearly taking the eastern horizon; cold chill started to penetrate my parka; the session was ended. Lulin's apparent motion currently takes it along the ecliptic in a retrograde path along a line between alf Lib (Zubenelgenubi) and alf Virgo (Spica). This means it is traveling outbound from the Sun at a low inclination to the solar system's plane. Overall, this was worth the drive after a couple of weeks of cloud out in the valley. A nice early morning treat. If driving out of the city, I would recommend leaving about one-half hour earlier than I did and arrive at 5:15am. Plan to stay until 5:45am. Tomorrow morning (2-1-2009 12:15UT; 5:15MST), Comet Lulin will be a degree north of the HD135208-HD134812-HD135230 triangle and will still be easily found from a semi-rural sky using 8x35 binos. Clear Skies - Kurt
Two items, neither of which takes up much room in the car: Folding camp chair, and a parallelogram. The zenith is suddenly prime binocular territory. If your tripod is tall enough, you can dispense with the chair. Great report, thanks! On Sat, Jan 31, 2009 at 6:08 PM, Canopus56 <canopus56@yahoo.com> wrote:
Mars was bright and directly at the zenith and 2 magnitudes brighter than Spica. (Mars was not positioned for binocular observing.)
participants (2)
-
Canopus56 -
Chuck Hards