Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 12/08/2011 - 14:07
K35 has now been used in about a dozen nights for photometric calibration, and so we have a pretty good handle on the transformation coefficients. They are:
Tv [B-V] = -0.008 +/- 0.010
Tbv = 0.983 +/- 0.016
Tvr = 1.024 +/- 0.023
Tri = 1.001 +/- 0.022
Tvi = 1.028 +/- 0.018
The mean extinction coefficients are:
Kv = 0.140 +/- 0.015
Kbv = 0.138 +/- 0.016
Kvr = 0.041 +/- 0.009
Kri = 0.035 +/- 0.008
Kvi = 0.076 +/- 0.009
These numbers are fairly typical of the Astrodon interference filters plus an STL-1001E camera.
Note: The Astrodon B filter has a red leak; you should not take data of objects that are redder than (B-I) = 5 without corrections.
Where can I find the UBV transformation coefficients for the SRO50 system. The SRO50 web page has lots of good information, but no information on the transformation coefficients. That would be a good place to list them.
Hi Jeff,
We just finished acquiring new data for calculating the coefficients. As we have been busy with the annual meeting, there hasn't been time to perform the analysis. I'll try to do so before I leave for the solar eclipse, so that you will be able to report the recent AZ Cas observations that SRO50 has been taking for you.
Arne