AAVSO Bulletin 74 for 2011- Letter to Observers

Letter to Users of 2011 Bulletin

                                                                                                                                     February 2011

Dear Observers,

There are several changes to the AAVSO Bulletin this year in content, format, and methods of access. These changes are exciting, providing a more flexible Bulletin that you can customize to serve your observing and research needs. The number of stars has been reduced partly in order to help focus the observing energies of you, our observers, on those long period variables we feel very strongly must continue to be observed on a regular basis.

The dates in last year's AAVSO Bulletin (Number 73 for 2010) were less precise than usual because observed dates for 2009 were not determined. I am happy to say that for AAVSO Bulletin 74 for 2011, we resumed the previous method of determining the most recent observed maxima and minima dates before generating the predicted dates for 2011. Thus, the dates in AAVSO Bulletin 74 have the same level of precision as in years prior to 2010.

In Bulletin 74, only those stars with an AAVSO mean curve have been included; the stars in previous Bulletins indicated with an asterisk (*) as having no mean curve have not been included this year. Some of these stars will be added back to the Bulletin as mean curves are determined for them. Also, some stars that are in this year's Bulletin will likely be discontinued in the future due to persistent severe difficulties in observing them.

I realize that there are a great many astronomical objects competing for your observing time, especially for users of moderate- to large-sized telescopes and CCDs. However, I urge you not to neglect the AAVSO Bulletin stars! There are still numerous stars in need of better coverage, particularly around minimum - even stars whose behavior at minimum no-one has ever seen. If we are to determine dates of minimum accurately, we need to know how these light curves look around minimum. When you browse through the light curves (use the Light Curve Generator link in the new Bulletin table), look for ones with sparse or no coverage and choose one or two of these to follow through minimum for a few cycles if you can. You will be going where no-one has gone before!

The Bulletin 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. Take a look at the table of AAVSO maxima and minima dates from 1900 to 2008 (use the link in the new Bulletin table) and see the unique history you can be part of. 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