Published December 15, 2009
Volume 17, Number 12

Tri-Valley Stargazers Are Always Looking Up

Chuck Grant had his telescope out on October 9th, hoping to observe the crash-landing of the satellite designed to detect water on the moon. Like many other amateur astronomers in Northern California, Grant, the president of the local astronomy club Tri-Valley Stargazers (TVS), found his efforts stymied by a heavily clouded sky.

The viewing is often better from H2O, Hidden Hill Observatory, the club’s dark site. Reserved for the exclusive use of members, H2O is tucked away on leased property in a remote area south of Livermore. The site is about 2,400 feet up a hill overlooking a large, dark valley, with an excellent low southern horizon, the preferred orientation for deep-sky observing from the northern hemisphere, Grant points out.

While not as dark as the Sierra Nevada mountains, H2O is less affected by light pollution than Lick Observatory, the UC facility atop Mount Hamilton about 10 miles to the west, he continues. When it comes to “steady air,” essentially smooth, uniform-temperature wind with no distorting swirls, an important characteristic for high-precision observation, the UC observatory wins out.  “An interesting bit of local trivia is that Mount Hamilton is one of the best places in the world for steady air, which is why the observatory was built there,” Grant relates. “Our site is a better darkness-wise, but the air is not as steady.”

New moon weekends are the most popular viewing times at the dark site, but those who have a specific mission, for example making photographic sequences of various objects, venture out more often. Spending the time to photograph so carefully can be a rather solitary experience, Grant admits, but that is not the only type of activity the club offers.

Every year several members and their families make a longer trip to Yosemite for a weekend of observation at Glacier Point, more than 3,000 feet above Yosemite Valley. The excursion is often timed to coincide with the Perseid meteor shower, visible by telescope in the late-summer sky. “The meteors seen in showers are all probably about the size of a grain of sand, but they have so much energy they burn up quickly in a bright flash,” he explains. Other galaxies show up as faint fuzzy smears which, even though not clear visually, still startle with the realization that they represent hundreds of billions of stars, he adds.

The club meets regularly on the third Friday of the month, at the Unitarian Universalist Church in Livermore. Amateurs and professionals are welcome at the meetings, which often feature speakers from organizations such as NASA, Lockheed, UC Berkeley, and Lawrence Livermore National Laboratory.  TVS also conducts public outreach and astronomy education through presentations and star parties for area schools and local parks. The next meeting, on December 18, will be the Holiday Potluck. For more information, visit www.trivalleystargazers.org


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