2024-05-02, 09:39 PM
Yes you are correct, the vast majority of these stars are too faint, so yesterday I did another cut using the Gaia phot_mean_g_mag parameter. For the high velocity stars, there are eight that are between 11 and 13 magnitude. But I also have an 18-inch telescope that many have told me is unsuitable for spectroscopy, but it seems to work just fine. For the low velocity stars there are several dozen stars bright enough for my 8-inch telescope. I use a difraction grating for my low resolution spectroscopy, so I can go a bit deeper than it is possible with a slit spectrometer.
Yesterday, I tried feeding my lists to the CDS X-match service. The WISE and 2MASS calatogs seemed to give the most matches. I also matched my lists against the GAIA DR3 catalog just to check that all the ID's and locations were valid and that there aren't some other problems with my lists. The GAIA DR3 matched perfectly, as it should since that is where the list originated. The eight stars from the high velocity list I tried to match individually. I first entered the GAIA source_id into the CDS Portal, then checked all of the alternative ID's given in SIMBAD. Then I tried those ID's in ST4. Some matched and some did not. I also tried entering coordinates to see if ST4 has a star within a few arcsecs. I'm still working on this.
Anyway, if you want to shorten the lists I sent, cut off the phot_mean_g_mag at about 12 or 13. In any case, for now it is the matching that is a challenge. I can work out specific targets later. I just need a more effective method for matching GAIA DR3 source_id's with other catologs and with ST4.
Thanks again,
Antone
Yesterday, I tried feeding my lists to the CDS X-match service. The WISE and 2MASS calatogs seemed to give the most matches. I also matched my lists against the GAIA DR3 catalog just to check that all the ID's and locations were valid and that there aren't some other problems with my lists. The GAIA DR3 matched perfectly, as it should since that is where the list originated. The eight stars from the high velocity list I tried to match individually. I first entered the GAIA source_id into the CDS Portal, then checked all of the alternative ID's given in SIMBAD. Then I tried those ID's in ST4. Some matched and some did not. I also tried entering coordinates to see if ST4 has a star within a few arcsecs. I'm still working on this.
Anyway, if you want to shorten the lists I sent, cut off the phot_mean_g_mag at about 12 or 13. In any case, for now it is the matching that is a challenge. I can work out specific targets later. I just need a more effective method for matching GAIA DR3 source_id's with other catologs and with ST4.
Thanks again,
Antone