Newsletter of the Big Bend Astronomical Society, Inc. November, 1998 Jim Walker, Editor

Dr. Matthew Shetrone, Resident Astronomer with the HET at McDonald Observatory, gave a presentation at our December 9th meeting on the discovery of planets outside our solar system.  He characterized the search for these planets as a story of strong wills, misconceptions, false starts, dedication, and postprediction.

The ancient Greeks considered the possibility that such planets might exist.  Epicurus argued that because there are nearly as infinite number of atoms, there must be planets outside our own solar system.  Aristotle thought otherwise, arguing that the earth was the center of a rather restricted universe.

The modern search for ESPs (extra-solar planets) so far relies on spectroscopy, observations of the wavelength of starlight.  As a planet orbits a star, both the star and the planet move around their common barycenter, essentially their center of gravity.  The star moves through a small orbit with the same period as the planet.  An observer on the earth will see a periodic shift in the wavelength of the starlight, shorter wavelengths as the star moves toward the observer and longer wavelengths as it moves away.  The velocity of these motions toward and away from the observer can be calculated, and the size of the planet can then be estimated.

The first "discovery" of an ESP was announced in 1991.  By a strange coincidence, the supposed ESP had a period of exactly 6 months.  Unfortunately, the discoverer had failed to take the orbital motion of the earth properly into account.

A bit later, Geoffrey Marcy and Paul Butler at San Francisco State University made the first accepted discovery of an ESP, an object several times the size of Jupiter closely orbiting 51
Pegasi.  Swiss astronomers soon made similar discoveries around other stars.  So far, all of the ESPs are several times the size of Jupiter, and are closely orbiting their parent stars at distances as small as the orbit of Mercury in our own solar system.  To date, 300 stars have been examined for ESPs, and 16 such planets have been found.  As yet, no ESP has been directly observed visually, with the possible exception of a planet being ejected from a binary star system, seen by the Hubble Space Telescope.

The search for ESPs farther away from their parent stars will require more sensitive spectroscopy, for closer velocity determinations, and longer observation times.  For example,
Jupiter has an orbital period of nearly 12 years, so finding a Jupiter-like ESP at a comparable distance from its star would require many years of very precise observations.

The HET at McDonald is designed exclusively for spectroscopy.  When this telescope becomes fully operational, it will play an important role in the search for ESPs.

Dr. Shetrone's presentation generated a great many questions and much interaction, bringing us a little closer to understanding our place in the universe.

Jim Walker reported that Yvonne Newman has donated Murray's 12"  Meade LX200 telescope to the BBAS.  The scope is fully computerized.  When it is set up and aligned, it will
automatically slew to any of more than 64,000 objects in its data base.  Stan Billotte, Jim Sage, and Jim Walker brought the scope to Walker's house, where it will be set up for star parties.  We hope to have it operating at our forthcoming star party (see below).

Fran Sage moved and Bernie Zelazny seconded that the Society send Yvonne a letter of appreciation for this fine telescope.  The motion carried unanimously.
 

Treasurer Betty Grimm presented the following report: Bank balance 10/31/98           $708.12 November Activity  Receipts                                      50.00 Disbursements                                .00 Balance 10/31/98                      758.12 Less Newman Fund                 160.00 Less Lighting Fund                    100.00 Working balance 11/31/98       498.12

First National Bank in Alpine Savings Account Opened 09/95/98 09/25/98 Deposit                   1,200.00 09/30/98 Interest Earned               .46 Balance 10/31/98                  1,200.46

Murray Newman Fund CD  2,904.57 Interest Earned 11/18/98          34.98 Fund CD Balance                 2,939.55

Bernie Zelazny, BBAS Webmaster, has installed a counter on our website.  Since November 15, our site recorded 92 visitors.

If you have Internet access, it would be good to check our website before a star party for a late notice on the weather.  We'll try to post a message in time for you to know whether we're still on or not.  If you're not on the Internet, we'll try to phone you if there's a change in plans.

Bernie adds new links from time to time, so check our web page ever once in a while:

The Newsletter, among many other things, is now available online.  If you have Internet access, Bernie will let you know when the Newsletter is available.  You can then read it online and print anything you wish, including our monthly star chart.  Bernie is now archiving back issues of the Newsletter, which you can also read online.

Since the Newsletter has been on line, several members have indicated they no longer wish to receive a paper copy, thereby saving postage, printing costs, and paper - all of which represent substantial expenses. PLEASE LET BERNIE ZELAZNY OR JIM WALKER KNOW if you no longer wish to receive a paper copy of the Newsletter.  Several members have already done so, saving our society postage, printing costs, and paper - none of which are trivial expenses.   However, if you want to continue receiving a paper copy, that's OK too.  None of us members of the cyber elite will consider you a second-class citizen!

A dozen people gathered at the Walkers' on Monday evening, November 16, to watch the Leonid meteor shower.  There was little activity before 2:00 AM, so most people left by midnight. However, Bill Baker and I made a night of it.

The radiant in the Sickle of Leo rose about midnight.  We could readily trace the meteors back to the radiant.  While the radiant was low in the sky, we saw several meteors moving horizontally, parallel to the southern horizon.  As the morning wore on, we saw Leonids all over the sky, at a maximum rate of possibly 300 per hour.

We also saw a number of Taurids, much slower and dimmer than the Leonids, clearly radiating from Taurus.  Once we saw a Leonid cross the path of a Taurid.

As we were facing eastward a little after 2:00 AM, a meteor lit up the sky behind us, passing westward over our heads.  It was bright enough to light up the house and to cast shadows on the ground.  When we turned around, the meteor was gone, but it left a glowing trail for 5 or 6 minutes.  I believe this was the brightest meteor I have ever seen.  Bill was talking on the radio to Loyd Overcash at Limpia Crossing as this meteor came over.  Loyd saw it too.  We saw a couple of other meteors that lit up the ground, but nothing as bright as this one.

We took a lot of 10-15 minute time exposures with wide angle lenses and 800-speed film.  We got as many as four meteors on some exposures, but we missed all the really bright ones.  Your camera can't be everywhere in the sky at once!

All in all, we had a good night of meteor watching - no moon, and not too cold.  Let's try the Leonids again next year!  We won't be far from the 33.25-year peak, so we could have another good show.

The room in the ACR Building has a center aisle, which we think makes it a little more comfortable than the room in Lawrence Hall where we have been meeting most recently.

If you're new to the area and don't know where the ACR building is located on the Sul Ross State University campus, you can click here to go to an SRSU campus map or here to see a photo of the ACR building.

Please call or e-mail Jim Walker at 364-2467, or Bernie Zelazny at 837-1717 if you need further information.