Star pattern for TML test with light pollution
Posted 22 April 2013 - 03:59 PM
Posted 28 April 2013 - 06:51 AM
140mm > 11.8 but less than 12.1 (11.9 and 12mag stars are mising in M67 and the 12.1 stars were not resolvable) - I assume 11.9
The smaller apertures below 60mm are somewhat difficult, as the star pattern changes due to the "loss" of the fainter stars so I will next time make a star chart with only the stars below +11mag.
This result seems very plausible and means that I have so far overestimated the magnitude loss due to light pollution by about 0.5mag for 140mm aperture. Interestingly also that the magnitude loss is clearly going down with aperture as was to be expected.
Posted 13 May 2013 - 04:09 PM
Next good targets will be NGC6823 in Vul and NGC6910/NGC7031 in Cyg in September (Cotts: Thank you for suggesting these). I will prepare star maps with hopefully existing AAVSO magnitude values for these open clusters.
Posted 15 May 2013 - 02:11 AM