
TY  - JOUR
A1  - Sung, Hwankyung 
A1  - Bessell, Michael S. 
T1  - Standard stars: CCD photometry, transformations and comparisons
JF  - Publications of the Astronomical Society of Australia
JO  - Publ. Astron. Soc.  Aust.
Y1  - 2001
VL  - 17
IS  - 3
SP  - 244
EP  - 254
KW  - 
UR  - https://doi.org/10.1071/AS00041 
N2  - We discuss variations of the atmospheric extinction coefficients and transformation equations to the standard UBVRI system based on observations of standard stars during 1996–1997 at Siding Spring Observatory using a thinned SITe CCD and coloured glass filters. In the transformation from the initial natural system to the Landolt version of the standard system, a large nonlinear term related to the Balmer discontinuity was required for the U transformation. We then modified the U filter, and the subsequent transformation to the SAAO version of the standard UBVRI system had only small nonlinear correction terms for U, B, and I. The correction terms relating to U and B are evidently due to the Balmer discontinuity, while that relating to I seems to be due to the Paschen discontinuity at ? ? 8200 Å. We also compared the results with Landolt’s observations, and confirmed the difference between the two sets of standard stars (SAAO and Landolt). 
ER  -

