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Well, it urns out that ASAS-3 magnitudes are good but they have to be taken with a lot of care specially in crowded fields (resolution is 14" per pixel and magnitudes are the results of five apertures: 2,3,4,5,6 pixels which translates to the MAG_0 to MAG_4 columns). Grzegorz Pojmanski kindly gave me a formula in order to choose the appropriate aperture: aperture = 13 - average_magnitude; if ( aperture < 0) aperture = 0; if ( aperture > 4 ) aperture = 4; Also there is a need to be careful at the faint end. At the 13-14 mag. level, the scatter is too large to be confident in finding coherent variability at a 0.3 or 0.4 mag. level. the catalogue is extremely useful between 7 and 12th magnitudes. himself spoke out about this problems and it would be not happy at all to use the doubtful data in ASAS-3 when there are plenty of useful and amazing numbers to be inspected. The same goes for not too lagre amplitude supposed CV's. The data previous to JD 2452350 were taken with a different camera so from now on a noticeable improvement has taken place. It's not the same to use old or new data. However, large amplitude variables can still be studied perfectly. I think HadV100 is too faint to trust ASAS-3 data and this supports Kolya's decission. Best regards, Sebastian. > Date: Tue, 13 May 2003 11:28:16 +0400 (MSD) > From: "Nikolai N. Samus" <samus@lnfm1.sai.msu.ru> > Subject: Re: [vsnet-campaign-unknown 200] HadV100 is an unknown variable star > > Dear Dr. Kato, > > Had V100 has been selected for the next Name-List, to appear within a > month, as a reliable Mira-type variable. Upon your message, I have studied > the case again. Just two images in red light available in Aladin, plus the > bright 2MASS magnitudes, are quite sufficient for me to believe this is a > genuine large-amplitude Mira. Note also its VERY faint blue magnitude in > the USNO A2.0 catalog. > > Best regards > Kolya > > On Tue, 13 May 2003, Taichi Kato wrote: > > > According ASAS-3 data, the variation of HadV100 looks > > short-periodic. This may have possibly been a result > > of the faintness of this object, but it would be possible > > the variable may be a short-period variable with a range > > 13.7-14.5 V. The impression of the light curves are > > different between Haseda's and ASAS-3. > > > > Regards, > > Taichi Kato > > > >
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