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SkyProbe Photometric Data Query Help


General Description

This form can be used by registered CFHTLS users to browse the catalog of SkyProbe photometric data. SkyProbe is a small camera mounted on CFHT to provide a continuous stream of atmospheric attenuation measurements during observations. The sky transparency is obtained by measuring the flux of 100 - 400 stars in the Tycho photometric catalog and comparing the results to past observations. Since other systematic terms are calibrated, apparent variations in the image zero point are due to presence of clouds or haze attenuating the observed brightness of the stars in the field. Queries can be executed based upon time and filter constraints.

Search Constraints

Field Name Description
Date and Time Date and time (Universal Time) of SkyProbe measurements. Format example: Jul 25 2004 13:30:00. Example of a search for a range of dates: Jul 01 2004..Jul 25 2004.
Filter Name Name of filter used for SkyProbe measurements.


SkyProbe Query Tabular Output

Field Name Description
Zeropoint Attenuation in magnitude measured by SkyProbe.
Zeropoint Error 1-sigma error on attenuation.
RA Right Ascension (J2000.0) of SkyProbe image.
DEC Declination (J2000.0) of SkyProbe image.
Airmass Airmass of SkyProbe image.
Median Sky Flux Median sky flux in counts in SkyProbe image.
Number of Stars Number of stars used for attenuation measurement in SkyProbe image.