MegaPrime Elixir Nightly Photometric Solution Query Help
This form can be used by registered CFHTLS users to browse the catalog of Elixir nightly photometric solutions. These solutions are computed using all standard star observations taken during the nights for which they apply. The basic relevant photometric equations are:
where
m is the instrumental magnitude in the internal photometric system,
DN are counts in digital units,
EXPTIME is the exposure time in seconds,
M is the calibrated magnitude in the target photometric system,
Zp_obs is the observed zeropoint,
C_airmass is the airmass term,
C_color is the color term,
FILTER1 is the magnitude measured in the filter specified by FILTER1, and
FILTER2 is the magnitude measured in the filter specified by FILTER2.
Queries are executed based upon time constraints. The time span of a nightly photometric solution must be between Start and Stop (below) time in order to be returned by the query.
| Field Name |
Description |
| Start Time |
Start time of search period.
|
| Stop Time |
Stop time of search period.
|
| Field Name |
Description |
| Zp_obs |
Observed zeropoint for nightly photometric solution.
|
| Zp_ref |
Reference zeropoint for nightly photometric solution.
|
| Zp_err |
Zeropoint error for nightly photometric solution.
|
| C_airmass |
Airmass term for nightly photometric solution.
|
| C_color |
Color term for nightly photometric solution.
|
| Filter1 |
Name of first filter used for color term in nightly photometric solution.
|
| Filter2 |
Name of second filter used for color term in nightly photometric solution.
|
| Int_Phot_Sys |
Name of internal (i.e., instrumental) photometric system.
|
| Ref_Phot_Sys |
Name of target photometric system.
|
| NStars |
Number of stars used in computing nightly photometric solution.
|
| NTimes |
Number of observations used in computing nightly photometric solution.
|
The Canadian Astronomy Data Centre
