Hello all,
I have a question about the SKY2000 catalog. I am working with charts using a limiting mag of 8.1 and have found, even after installing the SKY2000 v3, that some stars are on the chart aren't visible in the binoculars and some that aren't printing are visible in the binoculars. I know this is an issue with SKY2000 and not CdC itself. Here are the details on two stars, one is showing up on a CdC chart the other is not, with the limiting magnitude set to 8.1: ** First star ** SKY2000 v3 (CdC): HD 30779; SAO 57465; BD+35 916 Visual Magnitude: 8.06 Spectral Class: A2 This star is showing up on the chart but is not visible with a binocular limiting magnitude (BLM) of close to 8.3. The magnitudes below were pulled from the online SIMBAD database: http://simbad.u-strasbg.fr/sim-fid.pl> | = mag*10/1.75 (in order to fit on screen) SIMBAD - magnitudes: Henry Draper: 8.00 photovisual ||||||||||||||||||||||||||||||||||||||||||||| Bonner Durchmusterung: 8.0 visual ||||||||||||||||||||||||||||||||||||||||||||| SAO J2000: 8.3 visual ||||||||||||||||||||||||||||||||||||||||||||||| Hubble GSC: 8.59 photgraphic ||||||||||||||||||||||||||||||||||||||||||||||||| Hipparcos Input Catalog version 2: 8.591 V magnitude ||||||||||||||||||||||||||||||||||||||||||||||||| Hipparcos Main Catalogue: 8.677 Mean VT magnitude ||||||||||||||||||||||||||||||||||||||||||||||||| AGK3 Catalog: 8.7 photographic ||||||||||||||||||||||||||||||||||||||||||||||||| Positions and Proper Motions (PPM): 8.7 mag ||||||||||||||||||||||||||||||||||||||||||||||||| Tycho-2: 8.732 VT magnitude ||||||||||||||||||||||||||||||||||||||||||||||||| ** Second star ** SKY2000 v3 (CdC): HD 30884; SAO 57477; BD+35 917 Visual Magnitude: 8.90 Spectral Class: A0 Dbl: 0.40"/ 0.60m This star is easily visible with a BLM of 8.3 even though SKY2000 v3 is showing it at mag 8.9. SIMBAD details: SIMBAD - magnitudes: SAO J2000: 7.7 visual |||||||||||||||||||||||||||||||||||||||||||| AGK3 Catalog: 8.1 photographic |||||||||||||||||||||||||||||||||||||||||||||| Positions and Proper Motions (PPM): 8.1 mag |||||||||||||||||||||||||||||||||||||||||||||| Hipparcos Main Catalogue: 8.105 Mean VT magnitude |||||||||||||||||||||||||||||||||||||||||||||| Tycho-2: 8.119 VT magnitude |||||||||||||||||||||||||||||||||||||||||||||| Hubble GSC: 8.17 photgraphic |||||||||||||||||||||||||||||||||||||||||||||| Hipparcos Input Catalog version 2: 8.37 Hp photometric ||||||||||||||||||||||||||||||||||||||||||||||| Bonner Durchmusterung: 8.3 visual ||||||||||||||||||||||||||||||||||||||||||||||| Henry Draper: 8.40 photovisual |||||||||||||||||||||||||||||||||||||||||||||||| It appears Tycho-2 is closer to the visual magnitude in both cases. I will disable the SKY2000 catalog and compare the fields with a CdC chart turning on only the Bright Star Cat. and Tycho-2 and see if this is closer to reality. Thanks for any insights you can provide concerning the SKY2000 catalog. Ben Cacace ------------------------ Yahoo! Groups Sponsor --------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/1.XolB/TM --------------------------------------------------------------------~-> To Post a message, send it to: [email protected] To Unsubscribe, send a blank message to: [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/skychart-discussion/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
