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.
The Latest News & Upcoming Events
Dr. Lum will give part two of his talk The Evolution of the Reflecting Telescope
. Watch this
space for details; and read below for information on part one of his talk, which was given at the
The reflecting astronomical telescope, making use of mirrors, was invented by Sir Isaac Newton in 1668 as a solution
to the problem of chromatic aberration in refracting telescopes, which use lenses. Initial versions of reflectors
suffered from unreliable mirror making technologies based on metal mirrors and lagged behind the technology of
refractors after the invention of the achromatic lens in the mid 18th Century. This changed dramatically in the late
19th Century with the coming of the ability to apply high efficiency reflective coatings to glass mirrors, better ways
to test the accuracy of their surfaces, and improved mechanical telescope mountings. Dr. Lum will discuss at length about
the early history of the people who were most responsible for this change to the dominant telescope technologies used
Dr. Kenneth Lum is 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.
H2O Open House
Our next open house is scheduled for Saturday, August 27th at the club's dark sky site,
Hidden Hill Observatory
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 6:00 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 to
see what you are doing, 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.
Upcoming star parties
We have planned the following star parties:
- August 27th, H2O Open House
- August 30th - September 4th, Barcroft outing with EAS
- September 2nd - Muslim Community Center in Pleasanton
- September 24th, Tesla Winery club star party
- October 7th, Pleasanton RADD outreach star party at the Senior Center
for further information.
The H2O Open Houses will be open to all club members and
the public. The Tesla Winery club Parties will be open to club
members and their guests. Start and end times for the parties
will be announced later, but we usually plan to arrive at
the observing site about 30 minutes before sunset and wrap
up around midnight. Mark your calendars now!
Each of our Tesla club star parties will have a theme, which will be
announced in advance. Possible topics include a mini-Messier
marathon, lunar features, a planetary night, star cluster
obseving, beginner's night, and constellation identification.
The theme for our September meeting will be "star clusters and
binocular highlights". This will be our last Tesla club star
party for the year.
TVS Crystal Wine Glasses For Sale
TVS is offering elegant crystal wine glasses for sale to club
members. You don't have to drink wine to enjoy the beautiful
TVS logo-etched stemware. Use them for your favorite beverage,
or they can be used as a beautiful container for small
plants. They are the perfect gifts for loved ones or friends.
Look for them at club meetings, where they will be sold for
$10/each. Don't drink alone, buy two! Support TVS. Thanks to
who got these wonderful glasses.
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
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
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.