Astro 28 - Field Astronomy in the Sierra and a Grazing Occultation of Aldebaren

June 1998

Astro 28 last Spring was a big success, and I decided to offer it regularly. The astronomical highlight for this second installment was a spectacular northern limit graze of the brightest star that can be occulted by the moon - Aldebaren - on a slender cresent moon at sunrise. The graze path passed over the Nevada border near Grover Hot Springs and Markleville - a great spot for summer camping. Our site was at Indian Springs Reservoir a few miles north of Markleville - a perfect blend of sparse pines for shade and wide open dark skies for enjoying the beauty of the summer Milky Way. During the day we explored the little town of Markleville, drove out to the hot springs (a bit too commercialized for most of us, alas), and swam in the lake next to camp. Saturday afternoon Karl, Tom and I used a tape measure and layed out a dozen stations and marked them for easy identification for student observers. The star is so bright and the moon so small that it was even going to be do-able by naked eye, and certainly easy in binoculars. Sunday morning early we all got up and caravanned out to just over the border. Walt Morgan and a smaller team from the east Bay also joined us to augment our massive effort. Skies were clear.... until just before the start of the graze when a cloud appeared, grew large enough to cover the moon for all stations, and squatted there during the graze. Ruined. ARgh!

Here's some of our graze team after the unsuccessful attempt. Bob Cisowski, Tom, Karl, and Pam Reynolds all appear here. A great team!