Sunday, August 16, 2009

Hot Jupiter!

Saturday, August 15 was a Public Night at Stephens Memorial Observatory. It was hot, hazy, and humid and, though viewing was set to begin at 9:30, folks began arriving just a little past 9:00 -- a sign it will be a busy night!

As twilight began to fade I trained the telescope on the red giant star Antares. The idea was to nudge the telescope a bit as the sky darkened and look at the neighboring star cluster M4. That didn't happen as constellation Scorpius was sinking into the trees to our south and west taking the star cluster with it.

I made an attempt to locate the beautiful star cluster M15 but could not find it. As Jupiter was rising from behind trees to our east, moved on to that planet. Lower-level air was hazy but the atmosphere was quiet and seeing steady. We were treated to some excellent views of Jupiter at low power (about 30X) and, much later, at 104X. The equatorial cloud belts were visible nearly all of the time and we occasionally saw traces of the north and south temperate cloud belts. Truly impressive.

The excellent turnout --more than 50 visitors including at least three children-- made it difficult to change magnifications and celestial objects during the course of the evening. Those who stayed late and were patient saw the higher magnification views of Jupiter plus a good look at the "faint-fuzzy" M31 -- the Andromeda Galaxy (actually looking quite bright with central brightness and extended nebulous area). A couple of satellite passes and at least one meteor (likely a late Perseid) were seen through the dome slit.

Light pollution illuminated the hazy lower atmosphere making low-elevation skies murky and bright. Stepping outside and looking directly overhead, however, we could easily see the great band of the Milky Way stretching across the sky, replete with dust lanes. The star cloud did not quite reach down far enough to the south to join constellation Sagittarius before being swallowed up in the bright Earthbound haze.

Last visitors to leave were a couple who were curious about constellations and what star cluster it was they saw the other night -- the Pleiades. We spoke for several minutes sharing meteorite experiences in the front lawn. I closed up the Observatory at about 11:30. It was a hot night but the seeing was excellent.

The telescope's R.A. tracking is pretty bad. Troubleshooting shows the clock is working well and the gear train is transmitting motion so the conclusion is the R.A. collar is slipping. I hope to address that problem within the next month.

Thursday, August 13, 2009

Perseids Meteor Watch

The 2009 Perseids Meteor Watch I worked last night (August 12) was very mixed in results. The Portage Park District set us up in a fine little park with no ground-level lights, a nice paved parking lot, and clear grassy areas. There was a wide view of the sky and a good southern horizon. A Sheriff's deputy was on hand as was the District's naturalist -- really good support, especially in case of a big turnout. Then there are the "buts"...

Admittedly we put the event together in hurried fashion. Word didn't get out to the public as broadly or with enough lead time so only a couple of families showed up.

Then there was the sky. We were very close to the city of Ravenna but I'd hoped we would be just far enough away to escape the light bubble. Not much luck there. As the Sun sank below the western horizon a funny thing happened ... twilight shifted to the south. Yeah, huge levels of light pollution rose up in the southern sky right through the heart of Sagittarius. So while the clear skies allowed us to see the Milky Way, with dust lane, directly overhead, its heart was obliterated by the "Ravenna Nebula." Too bad.

Attendees and volunteers did, however, enjoy a few very good Perseid meteors. I myself saw only about five; being busy with telescopes and chatting with visitors has its costs. The 6-inch Meade telescope worked well but was impeded for want of a really good polar alignment: it had problems centering on objects it was told to "GoTo" but tracked very well once there. The dew point was high and everything quickly became quite damp, even wet, as the night progressed. The extended AstroZap dew shield saved the objective from fogging, however, so we saw decent views of Jupiter with three moons, and very good views of the Andromeda Galaxy, and M15 (a globular star cluster in the constellation Pegasus).

I tore down after the official 11:30 close. Before getting into my car to leave, a very nice Perseid streaked across the sky leaving a trail that glowed for a second or two -- as if just for me. I headed home, a bit disappointed but recalled a few happy visitors who saw planets, stars, galaxies, and meteors!