Monday, April 24, 2000

Backyard Astro-Card Fun...

Last night I decided to quit work at 9 p.m. and haul out my 10" f/5.6 Dob "Pliskin" for a bit of galaxy hunting. I had put off taking it out over several nights, and finally overcame my feeling of "hassle" at carrying the scope 40 feet to the backyard. The evening had been beautifully clear and the temperature pleasant, so by 9:15 I was set up, using my 19 Panoptic (which had been relegated to the eyepiece case in favor of the 20 Nagler for months), a Telrad, Celestron 10x70 finder and sets 2 and 4 of Astro-Cards.

Across the yard, in direct line of sight, was my neighbor's kitchen window, fully illuminated and pouring enough light onto me to make dark shadows. Bummer. Behind me, the TV made the window blinds light up like a lightning storm was destroying the interior of my home. But, I decided trying was better than quitting. I am now in process of building a large "astronomy blind" that will sit atop the pool filter enclosure, between the neighbor and my observing site. I am sure the neighbor thinks I'm nuts. She may be right.

I began by looking for NGC 4361 in Corvus. This planetary nebula sits in an easy to locate position within the "sail" shape of the Crow. It seems far too elusive, until I noticed some clouds had worked their way over to cover only the part of the sky I was looking at. Drat!

I moved to Leo, hunting for NGC 3521. In the bright skies of suburbia, this portion of Leo, down south of the beast's haunches and belly, is plenty difficult to find. Fortunately, the galaxy sits close to 62-Leonis, a 6th magnitude star accompanies closely by a magnitude 7.8 star, pointing toward the galaxy. These stars were visible in my finder. The galaxy itself was quite large and bright. I estimate it at about 10'x5', with a bright core and seemingly gradual diffusion to its edges. Maybe dusty. The Astro-Card lists it as mag 8.9v, but the surface brightness of 13.2 seems deceivingly dim. Anyway, this one was a whopper, and worth coming back to visit.

I looked back at Corvus, and the clouds were moving east off of my target. I walked around the yard looking for more clouds, but none were there... only the neighbors and the city's light pollution to cope with. I began thinking of hauling the 18' out back after seeing that galaxy... all I need is more gumption!

Back to Corvus, I sighted the Telrad and landed on NGC 4361. Don't you just love it when it happens that way? In the 19mm eyepiece, the planetary had a brightish middle and seemed not quite round. It was big too... compared to many of the little planetaries I've been looking at lately. I think I recall seeing the central star, but am not 100 percent on that. I should take better notes. This object too was transfixing. I eyeballed it for a good amount of time, enjoying the 19 Panoptic. I find with the 19 that I can get my eye completely surrounded by the eyecup, and suddenly, all that exists are light years of emptiness and a distant wonder.

I popped up into the tail of Leo next. Using the finder, I kept going over the area just east of Delta-Leonis. Try as I might, NGC 3646 would not appear. Strange, since it is much smaller than NGC 3521, and although dimmer by magnitude, it is its equal in surface brightness. I spent a good amount of time failing on this one. Yet, just down below the "ain't there" sits a cluster of galaxies, containing the bright pair NGC 3626 and NGC 3607. Both shown easily in the eyepiece, and were a snap to locate. I could almost see others in the field, but ended up logging just the two bright ones and some Lumpy Darkness.

About this time, I convinced my wife, who was asleep on the couch with the TV going, to go to bed. Off went the TV, and as is by some strange coincidence, so did the neighbor's kitchen light. Everyone was asleep, and it was a lot darker out back.

I looked up at Coma Berenices. Mel 111, the open cluster we all see as the hazy triangular area of stars, was blinking in and out. My targets were the familiar NGC 4565, and a few less spectacular (but brighter) galaxies, NGC 4494 and NGC 4559. I accidentally ran into NGC 4494 first while looking for the big edge-on. 4494 was obvious. It is rather small, but that is in comparison to the bigger objects I'd been observing thus far. In fact, were it on my current observing list, I would call it large and bright. It magnitude makes it a good in-city target, listed at 9.8, and its surface brightness made it one of the brighter objects of the night. It was certainly brighter than NGC 4565, which I star-hopped to in my finder scope using the Astro-Card. 4565 was not as "big" as I'm accustomed to in the 18" Dob, but what could I expect considering the observing conditions. It was noticeably dimmer than NGC 4494. Still, it was pleasant to see this streak of light, and hints of its dust lane. Next, I worked and worked to star hop to NGC 4459. I had to use a bright chain of stars beginning just off NGC 4494 to get to a good jumping-off point. The stars, 17, 16, 14 and 15 Comae Berenices were obvious, and 15 turned me right toward the galaxy. This one was not so bright, seemed smaller than either of the other two, and was not remarkable. I know NGC 4559 is better than what I saw last night, for it is large, has a bright core, and is nicely elongated. The conditions coupled with a surface brightness of 14 made this mag 10 galaxy rather disappointing.

Finally, I thought I'd like something a bit different. I pulled out an Astro-Card for NGC 5534 in eastern Virgo. This is an area I am unfamiliar with, since when I think of Virgo, I think of the galaxy fields north of Spica, between Vindemiatrix and Denebola. This object, a small globular cluster, resides on the line between Mu-Virginis and Iota-Virginis. It is easily seen in 10" aperture, although it is grainy but unresolved. Size is 5' and its magnitude of 9.6v coupled with the smallish size makes it a good in-town target. I tried "walking" the Astro-Card over to NGC 5534, but no luck. There is an easily distinguishable asterism of stars, a parallelogram with an extra star along one major axis, and two bright pairs of one end of the figure which should have bracketted the galaxy, but mag 13.5 was just too dim for the skies, even though the object was small in size and possibly visible.

By now, the sounds of late night were evident. Even the nearby freeway failed to make much of a stir. I was tired but content. The backyard is a good place to spend a few hours unwinding. The Astro-Cards are a fun challenge. Other objects eluded me during the night. I have left them out of this report.

The scope is still sitting out back, just in case the sky cooperates tonight.

No comments: