David's Astronomy Pages
CCD Image Notes - Session 92
(2005-08-14)

 Previous Notes
Notes
(S91) 		  Notes (main listing)
Notes
(Main) 		 
Home
Page		   Next Notes
Notes
(S93) 		 
Notes from CCD Session 92 (S00092)
 
Sky Condition Graph
Sky Brightness Survey
Master Flat
 
>

Goto Images from 2005-08-14

Sky Condition Graph

Sky Condition Graphs for Observing Session 92

Notice 
1) Noticeable sky darkening between 21:00 and 22:00h UT
2) Variation in airmass as targets at different altitudes were acquired
3) Rapid deterioration in sky quality at 22:45h UT as shown by smaller Mag Zero Point values
(gap in FWHM / ZP data at 21:30-21:45h UT is due to failure of certain Globular Cluster images to image link)

See explanation of these graphs

Back to Top

Sky Brightness Survey

 

Back to Top

Master Flat

Master Flat
(Dusk Sky Flats near Zenith, with TeeShirt)
 
11 x 20s (average combine), clear filter, -15 deg C 
2005-08-14 (#92001-11) 
 
Master Flat
(TeeShirt Flats against illuminated board in Observatory)
Noise levels are much lower in this Master Flat Attempt (due to brighter 
incident light and higher number of frames used), however lighting is considered 
to non-uniform, leading to the bright spot being more off-centre.  
The possible impact of mirror flop can not be ruled out .
 
20 x 20s (average combine), clear filter, - 5 deg C
2005-08-14 (#90114-33) 

Back to Top

This Web Page: CCD Image Notes - (2005-08-14)
Last Updated : 2006-01-20
Site Owner : David Richards
Home Page : David's Astronomy Web Site