February 24, 2009: Carretera de la Cabra

The night of February 24, 2009 the comet Lulin was in its nearest distance from Earth and so it was visible to the naked eye in dark sky places.

We decided to make a short observation session and to try to take some photos from it. In fact, Javier Algarra (member of the S.A.G.) had called us in the afternoon confirming that he would be there taking some photos (he has been taking photos of the comet for the last days). For us was quite complicated to go to the observation place because we had previous engagements and we could not leave until 10:30pm.

In the last minute, Luis (a friend of Antonio) joined us and we finally arrived to the observation place around 11:00pm. Then, we discovered that we had forgotten the telescope rings. Antonio decided to return to Granada to pick them up and return in order to obtain some photos of the comet and to avoid loosing the night.

45 minutes later Antonio came back and we could mount the telescope. We make very fast (and imprecise) initial alignment but we discovered the the auto-guiding make a quite good job. After some problems with the camera batteries (the cold drained them quite fast) we took 13 photos of 3 minutes each of the comet Lulin.

After a preliminar processing of the images we have obtained the following images. Studying the isophotes we can notice the shape of the coma and we can glimpse some of its frontal tails (we probably need more exposition time to properly differentiate them). The greenish tone of the comet is due to part of its composition (cyanogen and diatomic carbon).

Photograph information:

• Camera: Canon EOS 400D. No mods and no filters. Primary focus
• Telescope: Sky-Watcher ED80
• Autoguiding: PHD Guiding y autoguiding solution from Lunático (EZG60 + Luna QHY-5 Mono)
• Mount: EQ6 Pro
• Exposure: 13x180s = 39m
• Adjustments: 2x180s
• Processing: IRIS and GIMP.