AAVSO Bulletin 73 for 2010 - Note to Users

Note to Users of 2010 Bulletin

IMPORTANT NOTICE

The predicted maxima and minima dates for 2010 are less precise than usual. They were determined this year using the observed dates from 2008 instead of 2009. As a result, for some stars the predicted dates of maximum and minimum may be off by a few weeks or more, particularly for less regular stars. They should be considered approximate and used for planning purposes with caution.

IF YOU ARE USING THE BULLETIN TO PLAN SATELLITE OR MAJOR GROUND-BASED TELESCOPE OBSERVATIONS, PLEASE BE **CERTAIN** TO CONTACT AAVSO HEADQUARTERS FOR MORE PRECISE PREDICTIONS, OR CHECK THE AAVSO LIGHT CURVE GENERATOR TO SEE THE STAR'S MOST RECENT BEHAVIOR.

If you need dates of observed maxima/minima for statistical or other data- or research-related purposes, please contact AAVSO Headquarters via email at aavso@aavso.org.

Also, the disquieting trend I first noticed two years ago is continuing, although some stars are showing better coverage: For many stars that have their maximum brightness around magnitude 10 or fainter, there is a noticeable decrease in the number of observations on the falling branch (that is, from maximum to minimum) than in the past. This trend does not appear in stars that have their maximum around magnitude 8 or brighter, even when the falling branch goes to magnitude 12 or fainter. In general, seems that stars roughly magnitude 8- 12 are well covered and magnitude 10-14 are suffering.

I realize that there are a great many astronomical objects competing for your observing time, especially for users of moderate- to large-sized telescopes. However, I urge you not to neglect the AAVSO Bulletin stars!

These stars have decades - some, well over a century - of ongoing data provided by you and your colleagues, and continued continuity is essential to the researchers who will be analyzing these stars in the decades to come.

Many thanks to each of you for your valuable astronomical contributions. We look forward to continuing to receive your observations!

Good observing,
Elizabeth O. Waagen
Senior Technical Assistant