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. Gregory Brennecka
Evidence for Supernova Injection Into the Solar Nebula

Friday, April 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, April 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

April's meeting

A scenario of late supernova injection into the protoplanetary disk is consistent with formation of our Solar System in an active star-forming region of the galaxy. Slight differences between the non-radiogenic isotope compositions of the first solids in the Solar System (calcium-aluminum-rich inclusions, or CAIs) and terrestrial rocks are pervasive. Dr. Brennecka's work shows that the isotopic compositions of elements spanning a large mass range in CAIs, are uniform, and yet distinct from the average Solar System composition. Relative to younger objects in the Solar System, CAIs contain positive r-process anomalies in isotopes A < 140 and negative r-process anomalies in isotopes A > 140. This fundamental difference in the isotopic character of CAIs around mass 140 necessitates (i) the existence of multiple sources for r-process nucleosynthesis and (ii) the injection of supernova material into a reservoir untapped by CAIs. These distinct nucleosynthetic differences between CAIs and terrestrial rocks provide the isotopic character of the last significant supernova to input material into the Solar System. Further details of this work can be found here and here.

Dr. Gregory Brennecka received a PhD from Arizona State University in Isotope Geochemisty in 2011 with a thesis focused on documenting and understanding the natural variation in uranium isotopes in terrestrial and meteoritic samples. Much of his academic research and interest is now dedicated to determining isotopic characteristics of the first solids to form in the Solar System and what these characteristics can tell us about Solar System formation and early evolution. Dr. Brennecka is particularly interested in understanding short-lived radioisotopes and the role that supernova input had on the protostellar nebula and the early protostellar disk.

H2O Open House

Our next open house is scheduled for Friday May 23 at the club's dark sky site, Hidden Hill Observatory, aka H2O. The Friday date coincides with a potential new meteor shower that is expected to result from debris from Comet 209P/LINEAR (see p.30 of the May issue of S&T). This comet is making an extremely close pass by Earth on May 26 and it is possible that a meteor storm could result as Earth passes through debris from its tail.

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.

Another open house is planned for Saturday, August 16.

Gert Gottschalk took some nice photos at our last open house.

Yosemite Star Party

David Feindel will be coordinating this year's TVS star party at Glacier Point, Yosemite National Park. We were lucky in drawing the new Moon weekend of June 27-28. Tri-Valley members who bring telescopes for public observing will receive free camping at the Bridalveil campgrounds. On these dates sunset occurs at about 8:35pm with sunrise at about 5:50am. Contact for more information.

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.