StanCam colour term
The transformation equations are in the form:
B-b=zp+ct*(B-V)-k*X-k'*X*(B-V)
Where B is the catalogue magnitude, b instrumental magnitude,
zp magnitude zero point, ct colour term,
(B-V) colour index,
k extinction, X airmass and k' 2nd-order extinction.
| Band |
Colour index |
Colour term |
Error |
Second order extinction |
| U |
U-B |
0.0869 |
0.0099 |
-0.03 |
| B |
B-V |
-0.0023 |
0.0009 |
-0.03 |
| V |
B-V |
-0.0636 |
0.0012 |
0.0 |
| R |
V-R |
-0.1149 |
0.0026 |
0.0 |
| I |
V-I |
-0.0586 |
0.0057 |
0.0 |
| V |
V-R |
-0.1147 |
0.0021 |
0.0 |
| R |
R-I |
-0.1108 |
0.0025 |
0.0 |
| I |
R-I |
-0.1175 |
0.0114 |
0.0 |
Note that for U and B bands second-order extinction of
-0.03 was always assumed.
This was computed with synthetic photometry.
U,B and I colour-terms were
computed with much less observations than V and R. The colour-terms are very
similar to ALFOSC, except maybe V and I.
These results were kindly provided by Vallery Stanishev.
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