Another clear night in Leo

by Randy Muller

It was clear again on Friday, March 3, and I observed once again from my backyard. My strong preference was to observe from Fiddletown on Saturday night, but since the weather was predicted to be bad, I decided to go out earlier. Since I had to work until about 6pm, I decided not to head to Fiddletown in the dark.

Determined to see new galaxies from my darkness-challenged backyard, I hauled out my laptop which contains not only my sky charting software, but also my logs from previous sessions. My plan for the evening was to determine the telescopic limiting magnitude, set the appropriate limit on my computer chart, and then visually search charts for galaxies in the region of Leo. Upon finding any, I would check to see if I had observed it before, and if not, observe it. Otherwise I would move on.

I was out earlier in the week, and once again, conditions were extremely and unpleasantly damp.

Once again I performed my seeing and transparency checks on the Trapezium in M42 and M109. I could see 6 stars in the Trap, but just barely. The seeing was notably worse than Tuesday night. On the other hand, I could easily see M109, so the transparency was notably better. Also, I was out about an hour later, so that may have had a significant influence on my results: M42 was lower, and M109 was higher.

However, the stars were twinkling a lot more than they were on Tuesday night.

I began in Leo, above the hind legs. I arbitrarily set the limiting magnitude on my chart to 12, and immediately found on the chart a mag 11.9 galaxy that I had not observed before, NGC 3599. This galaxy forms yet another triple group with NGCs 3607 and 3608, which are relatively bright and were easy to see. I could not see 3599, however. I spent quite a while searching in vain for 3599, before finally giving up after about 20 or 30 minutes. This is some kind of fun!

Next, I found the very faint (mag 11.1) and diffuse galaxy NGC 3646. To the south and west lay NGC 3507. It was very faint (mag 10.9) with a very stellar center.

I gazed at Algieba (aka Gamma Leonis) for a while. It's a beautiful bright double star and both components are nearly equal in brightness and have a rich golden color. It seemed to me that one of the components was slightly dimmer, and slightly whiter than the other.

Dew was beginning to form on my laptop screen and eyepieces.

My final acquisition for the night was the NGC 3239. This galaxy has a very prominent stellar center, and if I had been viewing this field casually, I would only have seen it as a star. With much study, an extremely faint halo was barely visible around the center. The center itself was easy to see and looked exactly like a star. The magnitude of this galaxy is 11.3.

My final target for the night was the dwarf elliptical Local Group galaxy Leo I, aka UGC 5470. This lies 20 arcminutes due north of Regulus, aka the Little King, Cor Leonis, the Lion Heart, the Star Royal and a plethora of other cool-sounding Arabic-derived names.

I couldn't see any trace of it.

Although I wish I had been at a dark site, observing galaxies in Leo from my backyard on Friday night was better than sitting indoors hoping Saturday would be a good night.

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