FourStar Exposure Time Calculator

v1.02

Enter the sky conditions, source magnitude and desired signal to noise. A default observing strategy will be output.

Values should update as changed (press Enter) or click "Calculate"

Gain:

Filter:

Seeing(arcsec):

Phot radius(arcsec):

Moon Distance (degrees):

Moon Phase (0-1):

Airmass (1-3):

Ambient Temp (degrees C):

Magnitude*:

Desired S/N:

*Total Magnitude. Calculations take into account the seeing and photometric radius assuming a gaussian profile. The optimal Phot radius should be approximately equal to the seeing.

Enter or modify observing strategy here to update totals at bottom.



Guider:
Pattern		Number
Loops:
ExpTime (s):		Custom value:

Estimated Background* (ADU):
Estimated Peak Counts* (ADU):
Final S/N
Total Exptime(s)
Total Obstime(s)		Total Obstime(hr)
Efficiency


*Estimated counts in one pixel for each frame of the set.