November 2015

Free Panel Discussion at 5 p.m. following Silent Sky at Main Street Theater - Rice Village

All are invited to the free 5 p.m. post-show panel discussion of Silent Sky hosted by the Houston Astronomical Society at the Main Street Theater - Rice Village location

Don't miss this special opportunity.

Panel members are:

  • Carolyn Sumners, Ph.D., VP of Astronomy & Physical Sciences at the Houston Museum of Natural Science;
  • Thomas R. Williams, Ph.D., Historian of the American Association of Variable Star Observers & Visiting Scholar in the Rice University History Department,
  • Bonnie J. Dunbar, Ph.D., NAE FRSE (corr), former NASA astronaut, UH Cullen College of Engineering, M.D. Anderson Professor of Mechanical Engineering, Director, UH STEM Center (Science Engineering Fair Houston (SEFH)), Director, Aerospace Engineering Graduate Program and SICSA Space Architecture, University of Houston.

 

Novice Presentation: How We Know What We Know

Original article appears in GuideStar November, 2015.

by Debbie Moran, Novice Chair

Henrietta Swan Leavitt

For November, we have had to postpone the proposed variable star talk to accommodate a conflict, so I will do a fun talk that I hope will bring you guys out for elections called “How We Know What We Know.”  How do we know how far away stars and galaxies are?  How do we know what stars and planets are made of?  Why do we think the universe began with a bang?  How do we know black holes exist if we can’t see them?

Come see how the new play “Silent Sky” opening November 7th at Main Street Theater has everything to do with this topic.  It's the story of Henrietta Leavitt, a Massachusetts pastor's daughter who leaves her home for a job at Harvard University's Observatory. There she catalogs stars from photographic plates and meets Peter Shaw, the head astronomer's apprentice, who makes her re-think her vow never to marry. Despite her lowly position and limited access to scientific equipment, Henrietta makes an amazing discovery. But will she get the credit? Will her health give out before she gets the answers she’s seeking? Hope to see you all there!

The HAS Dark Site: The Most Popular Member Benefit

Original article appears in GuideStar November, 2015.

by Amelia Goldberg

HAS Dark Site

Steve and I attended the picnic on Saturday, October 3rd. There was quite a turnout. It was good to see so many new people out there. As we walked out onto the field after dinner, it hit me that finally, after more than 30 years; the dark site is being fully utilized. There were people set up on the concrete pads. Seven of the loaner scopes were being used. The three telescopes in the main observatory building were being used to show our members some interesting objects, even Pluto. Members were in their private observatories. The private pads were in use. Members were tent camping. The bunkhouse was full and almost all the RV spots were being used.  This has been the vision for the dark site since conception.  It was a real pleasure to see that the dream has become a reality.

Some of the newer members might not have too much insight into how all this came about.  Back in the late 1970s and early 1980s, this site became the dream of the HAS.  The short story - the property was acquired and the building began.  The observatory, with its three telescopes was for use by all trained members.  A process for reserving a scope was set in place.  The original concrete pads were for all members on a first come first served basis. When the second set of pads was built, two of them were made larger than the others.  These two large pads are for 18” or larger scopes or for handicapped members.  The bunkhouse was a donation by one of our members.  It is also first come first served.  Just put your pillow or bunk roll on a bed to hold it.  It is really nice to be able to get a little sleep in a bed,   after a long night of observing. That’s one reason that there are RVs out there.  Some of us, me included, just can’t handle tent camping or trying to sleep in the car.  We’ve done both.  I was really happy when our name finally made it to the top of the waiting list and an RV spot opened up. 

After we started having picnics at the site, it was easy to see that we needed some tables and benches. Those were built by our members.  Grills were also installed under a cover.  This really makes it easy to hold picnics out there.

During Bob Rogers’ reign as Observatory Chairman, there was discussion at some of the Board meetings about the site not being used.  They wanted to find a way to make our members use it more often. It became evident that members would use the site more if they didn’t have to set up and take down every time.  Private observatories were the answer.  The provision for members to build their own private observatory at the site was part of the original design of the site.  The Dallas club had done this for years. Bob commissioned a couple of Observatory Committee members to look into this and come up with a proposal. Soon plots were laid out and members began building.  Now, there are members out at the site as much during the week as on weekends.

Word Cloud

All of this didn’t just happen.  It took a lot of dedicated people and a lot of hard work to accomplish.  I just thought that a reminder of how fortunate we are to have this special place was in order.

Amelia is an Astronomical League (AL) master observer, the author of the AL Universe Sampler Program, the winner of the Texas Star Party 1991 Omega Centauri award and the 1999 Lone Star Gazer award.

Observation's of the Editor

Original article appears in GuideStar November, 2015.

Finder chart

by Bill Pellerin, GuideStar editor

The Play, ‘Silent Sky’ at Main Street Theater

If you are going to the Main Street Theater to see the ‘Silent Sky’ play (about Henreitta Swan Leavitt, the discoverer of the period /luminosity relationship in Cepheid variable stars), you may wish to read up on her and her work before you go.

The book Miss Leavitt's Stars: The Untold Story of the Woman Who Discovered How to Measure the Universe (Great Discoveries), by George Johnson is available from many sources (including Amazon). I read the book some years ago, but in preparation for seeing the play I read it again, this time on my Kindle (because I can’t find my hardback copy). It’s a short book, and an easy read, so you can get through it well ahead of attending the play.

There’s lots of other information on her on the Internet, including an article on Wikipedia. Find it here:

https://en.wikipedia.org/wiki/Henrietta_Swan_Leavitt

Dr. Frank Bash at HAS meeting

I’m excited to hear from Dr. Frank Bash, the former director of the McDonald Observatory (1989-2003). He was a guest speaker at one of our HAS banquets, long ago, when we had those events. I’ve been fortunate to meet with Dr. Bash several times at the McDonald Board of Visitors meeting. Dr. Bash is best known, perhaps, for being the director when the Hobby-Eberly telescope was designed and built at the observatory site near Fort Davis. It’s a great telescope in many ways, and it was a bargain. When similar sized telescopes were costing $100 million to build the HET was built for $13.5 million.

The HET is now being outfitted to be the instrument used in the Dark Energy Experiment, which will characterize dark energy (the name for the unknown force that is causing an acceleration in the expansion of the universe) in the universe. This research could be groundbreaking in developing the understanding of this phenomenon.

Object of the Month: V473 Lyr—A Fast Changing Cepheid

Original article appears in GuideStar November, 2015.

V473 Lyr

by Bill Pellerin, GuideStar editor

Object:  V473 Lyr, (SAO 87008)
Class:  Classic Cepheid Variable
Constallation:  Lyra
Magnitude:  5.99—6.35
Period: 1.49078  days
R.A.:    19 h 15 m 59.5 s (2000 coordinates)
Dec:    27 deg 55 min 34.7 sec
Size/Spectral:  F6
Distance:   1,681 ly
Optics needed: Small telescope

Many HAS members will be attending the Silent Sky play at the Main Street Theater this month. The play is about Henrietta Swan Leavitt who identified the luminosity (intrinsic brightness) / period relationship in Cepheid variable stars. The prototype star is Delta Cep, which was the object of the month way back in September, 2006.

Eta Aql, another Cepheid is the object of the month in the June, 2015 GuideStar. Generally speaking, Cepheid stars are short period, low amplitude variables. Their light doesn’t change much, and the cycle of variability is short. V473 Lyr’s period is only about 1.5 days. The period and the amplitude of variation is, itself, variable so any results you obtain through your own observations may, well, vary.

The AAVSO has limited data on this star, and you can print a finder chart by visiting AAVSO.org. If you print a chart, make sure the orientation of the stars in the chart match the orientation of stars you’d see in your eyepiece. Join the AAVSO and submit your observations at AAVSO.org.

So, how did Miss Leavitt discover this relationship? She was tasked with getting data from photographic plates of the Large Magellanic Cloud. The stars in the cloud are approximately the same distance from us so the brightness of these stars could be compared. In her report she wrote, “It is worthy of notice (that) the brighter variables have longer periods” (From the book Miss Leavitt’s Stars.) Needless to say this was a great understatement of her discovery, but she was a cautious person and only had a limited number of examples of variable stars to work with.

The problem came to be the ‘calibration’ of the Cepheid variable stars. Once the distance to any one Cepheid star could be determined, the distance to all others could be determined using the inverse square law, which simply says that stars that are farther away are dimmer.

By the time Edwin Hubble discovered a Cepheid variable in the Andromeda Galaxy the ‘calibration’ was not very good. This resulted in his estimate of distance to the Andromeda Galaxy of 1,000,000 light years. As astronomers established better information on the Cepheid variables, the distance estimate changed to the better value of 2.1 million light years.

President's Message

Original article appears in GuideStar November, 2015.

by Rene Gedaly

Presidents of Regional Clubs

All Clubs Meeting: The Gang Was All There

Due to the inclement weather, Astronomy Day was rained out—did you get your RainedOut alert? But it was a big turnout for the All Clubs meeting and many HAS members were there. Dr. Patricia Reiff, Professor of Physics and Astronomy at Rice University, gave a great talk—if you missed it and you’re a member of HAS you can watch it from the website. Log in to astronomyhouston.org and click Recorded HAS Presentations from the Member Features menu along the right-side banner. Thanks again to our videographer Rob Morehead for making this such a special benefit of membership.

Justin McCollum, All Clubs

  I also had the privilege of meeting student member Clay Parenti at the All Clubs meeting along with his parents and younger sister. Clay and dad were sporting shirt patches from the Astronomical League Convention in Las Cruces, NM that they attended this past July. Mom is on the Board of Visitors of the MacDonald Observatory and Sis is also into astronomy. What a great experience to meet this family who are all active in astronomy.

HAS at Main Street Theater for 'Silent Sky’

HAS members will be at the sold out matinee performance Nov 8 of Silent Sky at the Main Street Theater in the Rice Village. Silent Sky is the story about Henrietta Swan Leavitt and the real women computers working at Harvard Observatory at the dawn of modern astronomy.

There will be a post-show panel hosted by the Houston Astronomical Society with Dr. Carolyn Sumners, VP of Astronomy & Physical Sciences at the Houston Museum of Natural Science; Dr. Thomas R. Williams, Historian of the American Association of Variable Star Observers & Visiting Scholar in the Rice University History Department, & Bonnie J. Dunbar, Ph.D. NAE FRSE (corr), former NASA astronaut, UH Cullen College of Engineering, M.D. Anderson Professor of Mechanical Engineering, Director, UH STEM Center (Science Engineering Fair Houston (SEFH)), Director, Aerospace Engineering Graduate Program and SICSA Space Architecture, University of Houston

All are invited at the 5 p.m. discussion, even if you have tickets for a different performance. Watch for further notices from Education & Outreach or contact Bram Weisman for more info.

 Shout out to Amelia

Amelia Goldberg has written the first of a three part series on what it is to be a member of HAS: how we got here, how to preserve what we have, and what plans we can make for the future. Don’t miss it.

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