Messier Marathon

    - FOCAL LENGTH (Smaller fields of view are rewarded.) The logarithm to the base 10, LOG not LN on your calculator, of your focal length in millimeters.  For binoculars, assume a focal ratio of f/4 in determining the focal length if you do not know the real ratio.  For example, a 50mm camera lens gets 1.69 points; whereas, a 10 inch f/10 SCT snags 3.4 points.

12. TELESCOPES

    All types of telescopes are allowed for this Messier Marathon. However, each instrument used must permit for verification by a witness.  Hand-held binoculars, therefore,  are not allowed. Mounted binoculars that allow the witness to see the same field of view as the observer are allowed. You may not switch instruments during your observing run.  If you want to try a different instrument, you must make another observing run.  You may submit only one of the observing runs, for any given date.

13. ADDITIONAL AWARD OPPORTUNITIES

    While this contest is scored on your rate of observing Messier Objects, to level the playing field for those observers who can not observe all night, TVS offers additional opportunities. A member who observes many of the Messier Objects during his or her observing run may submit a log to the club for TVS Messier Award consideration, if the observing run meets the requirements for those awards.  Obtain a copy of the TVS Messier Award fact sheet at the next general meeting, for all the facts.  Typically, the TVS Messier Awards prohibit the use of digital setting circles and you must keep a log of descriptions or sketches.

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    - SETTING CIRCLES (Star hopping is rewarded.)
Observing without setting circles of any kind, earns five (5) points.  Mechanical setting circles, if used, net three (3) points.  Digital setting circles, if used, get two (2) points.  Computerized setting circles that automatically slew to an object, if used,  receive one (1) point. Your whole observing run receives the same value.  For example, if you use digital setting circles for one observation, then all observations earn only two (2) points,  never more.

    - LIGHT POLLUTION (Light-polluted skies are rewarded.) The square of the difference between 6.0 magnitude and the unaided eye limit for your observing run.  If the unaided eye limit is better than 6.0 magnitude, no points are given. If the Moon rises or sets during your observing run, you may  use only two different point scores, depending on whether the observation was made before or after Moon rise or Moon set. For example, the limiting magnitude from Livermore on the night of the observing run was 4.3, because the faintest star seen was Theta Cassiopeia; therefore, you have 2.89 points.

    - DETECTOR (Use of non-visual detectors is rewarded.) Using the human eye gets one (1) point. A CCD camera provides three (3) points. Photographic emulsion merits five (5) points.

    - SITE (Remote observing is rewarded.)  Those who observe in their backyards are awarded one (1) point; whereas,  those who must drive away from home to observe benefit from two (2) points.

Book Report by Chris Cody

   This new column will give you monthly information about our latest acquisitions, and any other information pertinent to the library. Watch future Prime Focus editions for expanded library news coverage. The library is now stored on two rolling carts, similar to the AV cart. Jim Brown completed the carts on February 27. Thanks Jim! This allows us to begin placing spine labels printed with Library of Congress call numbers. Labeling makes it easier to group and keep books together by topic.

   Several books have been checked out for longer than six months. So, check under your bed, in the laundry hamper, or in the cat's basket. (I have been known to put a book I was reading on my desk, only to have it covered in an avalanche of mail, magazines, and projects.) At the next general meeting, please check the list of borrowed books. If you have an overdue book, please locate and return it so that we can all enjoy it.

   The little laptop that could, just can't any more and has gone to digital Nirvana. I am looking for a replacement, priced below $500. We need a 486 or faster processor, 4MB RAM, 500 megs memory and a 3.5 inch drive. If you have any leads, or can supply a good used computer, let me know at 707/747-6550.

Page 9         Prime Focus   April 1999