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.

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