NGC 6540!

by Marsha Robinson (Hitchings)


I couldn't wait for Saturday night. It was clear and dark on 7/5, so at 9:30-10:00 pm, I took out my Dobson 10" (f 5/6) out on the driveway. Because of my neighbors inside light being 100 ft above me, I thought I'd try something novel. I went to the front of the house, away from neighbors' lights, but facing the Santa Clara Valley from 800-900 ft elevation with its brilliant yellow diamonds glowing against the house. What could I lose? (This is in East San Jose off of Mt Hamilton Rd.)

Not thinking I could see that much, I started out in Scorpius looking at the Messiers there. M4 didn't look bad! M62 was bright. It looked like a butterfly with a vertical spine and stars that fanned out on either side.

OK, onto dimmer stuff and see what gives. Two open clusters at Scorpius' stingerH16 and NGC 6400. Because H16 lies between and just a little above the two bright stinger stars, it was more of a challenge, but definitely there. Finding NGC 6400 should have been easy, but I couldn't seem to locate it by making a triangle with star x and the left stinger star. Then I realized it was in a direct line between star G (also NGC 6441) and the the stinger star. Then it was an easy kill. A bright cluster, it was fairly large and lopsided with a larger grouping of stars at one side.

Sagittarius was in full view by this time, so I fished around for the nicer open globs: M28, 22, NGC 6638. Then I tried to find the center of the galaxy. I thought it was just above the spout, according to "Black Holes" PBS program. I just wanted to know where it was exactly to stare at it and see what I wasn't suppose to see. Make sense?

After reading the NGC 6540 controversy on TAC, I decided to see what that was all about. I used a 12mm Nagler so roughly I was at 200x.

NGC 6520 was an easy find. Starting from star Alnasl 10-Y and going north, you can't miss the bright (orange) variable star "W." Following that upward path, you can't miss 6520. It is small, but very rich in bright stars (mag 9-13). Also what you can't miss is Bard 86 right next to it. It is a small patch of black matter where no stars can be seen. I think in darker skies the black stands out greater against the Milky Way, but it's clearly there last night as well. Noting the direction of B86 from 6520, I went the opposite way and slightly north. When doing that, you can't miss a formation of stars similar to a sideways "V." When you see these stars, you know you've gone too far. According to the Millennium Star Atlas, p. 1415, I knew I needed to look for some fainter stars that looked like a small Scorpius, or a tiny Ursa Major but with just the handle and the first two bowl stars. I went back slowly and found those stars. Nestled between the "bowl stars" and slightly north was an extended faint patch of bright fog--very easily detected--NGC 6540. I was surprised to see how bright it was and how easily it was detected after a lot of talk that it wasn't detectable. Bump up your power and follow the stars!

I ended the session looking up in the "Teaspoon" for Palomar 9 or NGC 6717. That was really a fun find! Going north from Nunki, I went 2/3 the way to the west star in the teaspoon, near two stars. This one was faint and small. I could barely detect the nebula.

Last night I was very pleased with what I could get with my 10" above the Santa Clara Valley. It was one of my enjoyable observing sessions...right out my front door!!!