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Well, it depends on how he is reducing the data. If he uses something like the tass pipeline, iraf, etc. software, he will get the right positions. We have been getting errors of order a second of arc. What comes out is just positions and magnitudes. It is then up to the observer to attach some conventional name to the star. I will admit that this is not always so easy. If he makes use of all the stars in his images and a suitable catalog, then he will get good positions if not good magnitudes. Once you take CCD images, you might as well reduce everything in the image and use modern techniques to get it right. Then you are not dependent on someone who made a finder chart in 1936. Tom Droege At 03:08 PM 6/11/03 +1000, Mati Morel wrote: > Before Tom K. starts submitting data on V449 Lyr, I respectfully suggest >he specify exactly which star he has observed. There is some developing >confusion about the position of V449 Lyr. >Firstly, the coordinates published by Romano (and used by Guide 8) are bad. >Please disregard. >Secondly, Romano's finder chart is quite clear. His variable, no. 249, is >the middle star in a line of three running SW-NE. >See IBVS 645. This is my understanding of the identity of V449 Lyr, unless >he has published a later correction, somewhere ... >Coordinates for these stars are as follows (from B1.0), and mb from A2.0. > # (2000) mb > 1 19:07:35.66 +43:59:53.9 14.9 (GCVS id) > 2 19:07:37.07 +44:00:20.1 15.0 (Romano) > 3 19:07:38.63 +44:00:43.3 12.4 > >Star 1 is listed in the GCVS, but appears to be in error. >Star 2 is Romano's variable 249 = V449 Lyr, on his finder chart. >The rough position published in IBVS 3701 is consistent with star 2. >Perhaps the published maximum mag. for this star is a typo, or the result of >confusion with star 3. >The B1.0 magnitudes for star 2 are as follows : B1 = 15.94, B2 = 18.20, R1 >= 14.43, R2 = 15.58, I =14.04. > >Regards, >Mati > >----- Original Message ----- >From: "Brian Skiff" <Brian.Skiff@lowell.edu> >To: <dhkaiser@sprynet.com> >Cc: <aavso-discussion@informer2.cis.McMaster.CA> >Sent: Wednesday, June 11, 2003 7:25 AM >Subject: Re: [AAVSO-DIS] V449 Lyr - does AAVSO want my data? > > > > It is worth noting that there is indeed _no_ published study of > > this star, and only recently have the GCVS group given a precise > > position for the star. The current 'best' position is from 2MASS: > > > > V449 Lyr 19 07 35.68 +43 59 53.0 (J2000) > > > > SIMBAD shows only the discovery paper, which has no lightcurve >information, > > and Mati Morel's IBVS flyer with a somewhat improved position (the on-line > > GCVS is better still, and the 2MASS position more-or-less definitive). > > The star is fairly faint on all Schmidt plate scans, so (as Mati >suggested) > > the nominal maximum magnitude could be too bright. > > I note that the 2MASS J-K color is about 0.6, which is the color of > > an unreddened K0 giant. Thus instead of an Algol- or W UMa-type eclipser, > > it could be an RS CVn type---assuming the classification as an ecliper > > is correct at all. > > > > \Brian > > _______________________________________________ > > aavso-discussion mailing list > > aavso-discussion@mailman.McMaster.CA > > http://mailman.McMaster.CA/mailman/listinfo/aavso-discussion > >_______________________________________________ >aavso-discussion mailing list >aavso-discussion@mailman.McMaster.CA >http://mailman.McMaster.CA/mailman/listinfo/aavso-discussion
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