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[AZ-Observing] Photometric Night Definition
- From: edwin hubble <hubble_edwin@xxxxxxxxx>
- To: azObserving <az-observing@xxxxxxxxxxxxx>, hubble_edwin@xxxxxxxxx, isac_81@xxxxxxxxxxx, keith@xxxxxxxxxxxxxxxxx
- Date: Mon, 12 Feb 2007 09:47:05 -0800 (PST)
In response to Keith Schlottman's question, two days
ago, I can contribute the following:
As I understand it, the Sloan Digital Sky Survey
standard for a photometric night is as follows:
During the night, the repeated measurements of
brightness of an object, very carefully calibrated
with all sky photometric reference stars, should have
a root mean square deviation from the mean of less
than 0.02 magnitude.
They use a dedicated 50 cm photometric calibration
instrument to do this, next to the 2.5 meter survey
telescope.
Their photometric calibration stars have been observed
by the Naval Observatory in Flagstaff.
A specification much tighter than 0.02 would give too
few nights to be practical.
Victor Herrero
hubble_edwin@xxxxxxxxx
http://hubbleed.bravehost.com/
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