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MBK Team's Extinction Calculator

When comets are observed at high zenithal distances (low in the sky) the absorption of light of objects (comparison stars and the comet) is different if they are seen at different elevations. A differencial extinction correction must then be applied.
This tool calculates the atmospheric extinction. You must supply your site's altitude and the object's elevation. After you press "Calculate" you get three results for the atmospheric extinction. You use "Winter extinction" if you observed in dry, winter-like conditions, "Summer extinction" if you observed in humid, summer-like conditions or "Average extinction" if you observed in average conditions.

Enter your site's altitude (meters):
Enter object's elevation (degrees; zenith = 90):
Winter extinction
Average extinction
Summer extinction

Calculations are based on the paper by Green DWE: Magnitude Corrections for Atmospheric Extinction. ICQ 14 (1992): 55-9, available at http://cfa-www.harvard.edu/icq/ICQExtinct.html.

If you have any comments please write to MBK Team.

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