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[vsnet-obs 4093] Re: vis.obs. (fwd)

 
 My comments on the note "my too bright" observations (vsnet-obs 4088) by 
 observer LTO :
 When four observers with large telescopes observe that a variable is faint
 and one who observes with a relatively small instrument sees it several (!) 
 magnitudes brighter, I have the suspicion that the latter has misidentified  
 the variable. To state that "and there are no other stars near [SS Cas or RR
 Per] with the brightness I have seen" is in many cases absolutely untrue, for
 the stars R Cas, Y Cas and RR Per for instance. It is one of the strangest 
 criteria for the identification of variable stars I have ever met. When stars
 are very faint in the instrument, an AAVSO e-type chart should be taken,
 especially in crowded star fields.
 The observer LTO has misidentified more variables like R,UW And, R,Y,SS Cas
 RR Per, R UMa after my opinion. How to identify the variable carefully is 
 described very clearly in "Manual for Observing Variable Stars" by Margaret W.
 Mayall, revised edition, (1957), chapter 5 : Identifying the Variable.
 The observer LTO is also overobserving stars, like T Cas. These stars with
 relatively long periods should not be observed more frequent than once a week
 to avoid biasing.Further the Annual Predictions of the AAVSO or the Previsions
 
 des Maximums et des Minimums .... of the AFOEV are useful for planning the
 observations. For most variables that are regularly under observation they are
 reliable.
 -- 
 Georg Comello                           | Tel.  : (31)-50-3634050
 Kapteyn Laboratorium                    | Fax   : (31)-50-3636100
 University of Groningen                 | E-mail: comello@astro.rug.nl
 P.O. Box 800,  9700 AV Groningen        |
 The Netherlands                         |
 
 
 
                                         Georg Comello        tel. 4050
 


-- 
Georg Comello                           | Tel.  : (31)-50-3634050
Kapteyn Laboratorium                    | Fax   : (31)-50-3636100
University of Groningen                 | E-mail: comello@astro.rug.nl
P.O. Box 800,  9700 AV Groningen        |
The Netherlands                         |