1.3-m Photometric Standards

1.3m Observations of General-Purpose Photometric Standards and Reports of Calculated Measurements

General-purpose photometric standards are observed every photometric night on the 1.3m telescope.

The procedure is as follows:

Each photometric night, 1 Landolt field is observed ONCE in all optical filters. In addition, 2 IR standards (one blue and one red) are observed ONCE in all IR filters. Because extinction coefficients cannot be calculated on such nights, "default" values (see below)are used for calculations of zeropoints and color terms.

Periodically, more thorough observations of the same standards are performed, observing each of the 3 standard fields (1 Landolt, 2 IR fields) at 3 different airmasses in order to calculate extinction coefficients. The medians of these values, taken over many months, are the "default" extinction coefficients mentioned above.

Standard star images are available to all users and are not charged against their allocation. We do our best to choose those Landolt fields with at least 3 standard stars available in the field of view. If your program requires additional standard observations, please include them in your PhaseII submission. Additional observations are charged against your allocation.