Return to Home Page
Dear Taichi, > The main difficulty of PIXY would be that the software tries to make > catalog correlations with a single catalog (e.g. GCVS) at one time. > To the "eye" of the correlation software, the sky would look "filled with > variable stars only". If the software would incorporate multiple catalog > correlation (e.g. combination of GCVS and GSC/USNO), confusions with > "bright nearby stars" would be more efficiently removed. It would be > even adequate not to report anything when there is a bright cataloged > nearby star. I do not think so. Actually, what you wrote is the way I used using the old version of the PIXY System (PIXY 1). But finally, I judged it was useless function, and I deleted it from the new version (PIXY 2). Your solution can remark some stars whose magnitude data to be deleted. But it will not be perfect, due to the incompleteness of catalogs. So I had to check all stars by eye anyway, even using the function. No time was reduced. That is why I judged it is useless. There are some other remarkable problems in the GCVS catalog. One is that it contains many stars whose position is inaccurate. Another is that it does not contain a proper magnitude. Actually, it contains a variable range, but it is extremely unreliable. For example, a 19B mag star can be detected from unfiltered CCD images around 11 mag or so! From the viewpoints of them, I recommend to create a proper catalog too, which only contains stars with accurate position, and which contains proper magnitude or only stars which can be detected on your images. > This problem needs to be fixed from the both sides: PIXY and Maciej. > It may simply be a result of bad CCD response (non-linearity etc.), > or the combination of problems in PIXY and Maciej's method. Once Maciej I imagine the Maciej's style, not trailing stars because the camera is on the fixed mount, can be a reason. But still I do not know. I hope Maciej send me some sets of images of the same field on the same night for investigation. Best regards, -- Seiichi Yoshida comet@aerith.net http://www.aerith.net/
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
