Thread: Ngc 7793
View Single Post
  #39  
Old 06-11-2014, 12:58 PM
SamD's Avatar
SamD (Sam)
Registered User

SamD is offline
 
Join Date: Jan 2014
Location: Brisbane SW
Posts: 71
Quote:
Originally Posted by RickS View Post
PI annotation script and it noted PGC687110 but not PGC3169353
Not sure about the PI annotation script, I thought it would have grabbed all the galaxies from the PGC. Maybe the smaller galaxy is not displayed because it's so close to the much brighter PGC687110, or maybe there's a magnitude threshold ?

If you use your image RA and Dec bounds and query the PGC directly you get about 120 galaxies in total:
http://leda.univ-lyon1.fr/leda/fullsql.html

select * where al2000 > 23.93833 and al2000 < 23.99278 and de2000 < -32.2967 and de2000 > -32.9361 and objtype='G'

Also the fairly dark sites match my recent calculations on CCD Limiting Magnitude. When I put your equipment and exposure times into my spreadsheet I get a stellar VMag limit of about 22.4 (with 21 VMags/arcsecs2 skies), vs 21.9 (with 20 VMags/arcsec2), and 22.9 with 22 VMags/arcsec2.
Reply With Quote