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Earthshine blog

"Earthshine blog"

A blog about a telescopic system at the Mauna Loa Observatory on Hawaii to determine terrestrial albedo by earthshine observations. Feasible thanks to sheer determination.


Observing log Posted on Jan 13, 2012 17:37

T fell to -3 degrees C outside. Inside the dome it was as low as 2.7 degrees C. About 30% of images were all right. RH very low. Wind near 8m/s.

Hit kill switch again at Alt 75 degrees near meridian. Mount calibration may be lost now – but seems to be less than a few pixels.

Target drift

Mechanical design Posted on Jan 13, 2012 17:35

In a sequence of observations of Mars (using Sidereal tracking) we sought to learn if there is a periodic error in the tracking. We plot the pixel coordinates of Mars in the session covering several hours:

What is most evident is that Mars drifted relative to the frame – but this may be the actual motion of Mars, although it seems a lot (Mars moves in RA mostly, not DEC – i.e. Y). This can be checked against the position of the stars in the frame – more later.