SpeX Parallactic Angle Calculator

SpeX PARALLACTIC ANGLE CALCULATOR


This form can be used to estimate the parallactic angle and differential atmospheric refraction for observations with SpeX. The output is in degrees from North through East.

Questions about SpeX and its expected performance should be directed to John Rayner (rayner@irtf.ifa.hawaii.edu).



Input Observing Parameters

Select an Observatory:

Give the Hour Angle of the Object (hours min sec):
(include neg sign with first non-zero entry)

Give the Declination of the Object (degrees min sec):
(include neg sign with first non-zero entry)

Give the Barometric Pressure (in mm Hg):

Give the Water Vapor Pressure (in mm Hg):

Give the Temperature (in degrees C):



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