Welcome to the Tri-Valley Stargazers Astronomy Club's web site. There is a lot of information here on the many activities of the Tri-Valley Stargazers (TVS). Learn why you should join the club to get the most out of your amateur astronomy hobby in the east San Francisco Bay Area.


Next Public Meeting

Speaker: Dr. Kenneth Lum
Historical Innovations in Telescope Technology in England in the 17th and 18th Century - A Tour with the Antique Telescope Society

Friday, July 18, 2014
Doors open at 7:00 p.m.
Lecture at 7:30 p.m.
Show and Tell follows

Unitarian Universalist Church
1893 N. Vasco Rd., Livermore

Next Board Meeting

Monday, July 21, 2014, 7:30 p.m.
Round Table Pizza
1024 E. Stanley Blvd, Livermore

Members are always welcome at board meetings. Pizza is optional.

The Latest News & Upcoming Events

July's meeting

Following the invention and initial improvement of the telescope in the Netherlands in early 17th Century, most of the innovation in telescope technology passed into England in the late 17th Century with important contributions mainly by the Germans. Most notable of these were the invention of the reflecting telescope by Isaac Newton in 1668 and the achromatic lens beginning around the 1730s by Chester Moore Hall and John Dolland in England, and Samuel Klingenstierna in Sweden. These innovations improved the most pressing defects of telescopes at the time which were chromatic aberration and spherical aberration. They allowed telescopes to be built with shorter and more manageable lengths while giving better images. Improvements in metal working technology driven by the Industrial Revolution in England and glass making technology in Germany allowed larger and more mechanically precise telescopes to be made by the 18th and early 19th Centuries. Dr. Lum will give a travelogue of some of the places where some of these innovations took place along with visits to other important places in the history of astronomy in England during a 1996 Antique Telescope Society visit. Among the places he visited was the house in Bath, England where William Herschel and his sister, Caroline lived and discovered the planet, Uranus, in 1781, and the Royal Greenwich Observatory where efforts were made to determine longitude at sea.

Dr. Kenneth Lum is recently retired from the practice of Emergency Medicine. Since high school, he has also been an enthusiastic amateur astronomer, having built two telescopes at the Adler Planetarium in Chicago and a large Newtonian reflector when he reentered amateur astronomy in 1986. He pursued an interest in astronomical photography during the 1990s and continues to study the history of astronomy and astronomical instrumentation. Dr. Lum is currently interested in ways to enhance the performance of small telescopes with the use of a photomultiplier eyepiece and astronomical video cameras. Since 1994, he has been traveling with the Antique Telescope Society almost annually visiting different historical astronomical observatories.

Barcroft High-Altitude Star Party

This year's White Mountain star party will be held from Sunday September 21st through Friday September 26th. This joint venture with the Eastbay Astronomical Society is held at the University of California's White Mountain Research Center. The fee for attending is $65 per person per night. The location of the site plus its altitude of 12,450 feet assures exceptional viewing conditions. But it also offers some interesting challenges for people who are not accustomed to the high altitude. Please visit EAS's web page for a detailed description of this year's party. To sign up, contact .

H2O Open House

Our next open house is scheduled for Saturday, August 16 at the club's dark sky site, Hidden Hill Observatory, aka H2O.

Anyone can come to our open houses, not just club members; but you cannot go there without an escort. We will meet at the corner of Mines and Tesla Roads at 6:30 PM, then caravan to the site on a drive that takes about 50 minutes. The admission is $3/car; please bring the exact amount. There is no gas on the way, so be sure to gas up before leaving. The site is essentially in the wilderness, so there is no electricity and water, and there are only a couple of pit toilets. Cell-phone reception is iffy at best. While there is a picnic table there, you really should bring your own chair. If you need a flashlight, bring a red LED flashlight, not a white-light flashlight. And use masking tape over your car door and interior lights, or pull the fuse. If you don't have a scope, you can always find someone who is willing to let you look through theirs. And don't forget to bring your binoculars. Expect to stay until about midnight and get back to Livermore at around 1:00 AM.

Gert Gottschalk took some nice photos at a recent open house.

Magazine Giveaway

TVS has back issues of S&T and Astronomy magazines freely available. If you are interested in being a recipient of these valuable resources of astronomical history, please make your interest known at a forthcoming club meeting. First come, first serve!

TVS Logo Wear

You may have seen some TVS members wearing shirts and jackets embroidered with the TVS logo. If you are interested in obtaining an embroidered logo item, you can do so by ordering whatever you would like through Land's End's Corporate Sales section and specifying TVS logo #0118948. You will need to set up an account, which will ask for the logo number and the TVS customer number (3452021).

TVS has also set up shop at Cafepress for members to buy non-embroidered TVS logo wear. You can have the TVS logo put on t-shirts, mugs, buttons, hats, coasters, etc. You buy through Cafepress, and Cafepress sends TVS a portion of the proceeds. Visit the web site to see all the TVS logo possibilities.