CFHT, Observer Information, Alamanac.

Astronomical Sky Calculator


Based on a sky calculator programme written by John Thorstensen of Dartmouth College.


Precesses coordinates, provides sun & moon rise & set times, moon phase, LMST, Galactic coordinates, parallactic angle, an hourmass table, Julian date, moon phase and more besides. Just provide location, date, time and coordinates. CAUTION: this web interface performs only very limited validity checking, please do not try and find these limits.

Calculate for:
Date (yyyy mm dd):
Time (hh mm ss): Local Time: UT:
Coordinates: RA: Dec: Epoch:
See also:
Brian Casey provides another interface to John's programme, this time as a calculator of general phenomena for each night in a selected range of months.
Source code, Cautions and Legalities
Algorithms and Accuracy