Software and calculators
Software and calculators
The following software tools and calculators may be of assistance when planning observations or reducing data.
Astrometry
If you have astronomical imaging of the sky with celestial coordinates you do not know—or do not trust—then Astrometry.net is for you. Input an image and they’ll give you back astrometric calibration meta-data, plus lists of known objects falling inside the field of view.
They have built this astr...
Astrotime
Astrotime by Bob Nelson, is a small downloadable application that produces a wealth of time-related outputs from input data including your location, time, star RA and Dec. Outputs are RA/Dec conversion to another epoch, JD, HJD correction, local sidereal time, alt/az coordinates, airmass, hour angle...
Bob Nelson’s EB Min
Bob Nelson’s EB Min program for downloading (freeware) generates predictions of EB minima for your date, location and local horizon. It comes with a very extensive Excel database with elements of some 6000 eclipsing binaries. Along with each set of elements is the source, date of the last time of mi...
C-Munipack
C-Munipack is a software package which offers the complete solution for reduction of images carried out by CCD camera, intended on a observation of variable stars.
Each step of reduction process can be run from the command line or via simple and intuitive graphical user interface.
Calculate ToM for EBs
Spreadsheet for calculating & displaying tables of times of primary and secondary minima for eclipsing binaries. Enter period and epoch and start date, and the calculator does the rest. Pull down the last row to get dates/times further into the future.
Convert multiple UT-JD datetimes
Spreadsheet for converting multiple UT dates/times to JD and vice versa
Ephemerides
Ephemerides is a computer program which computes times of minima of eclipsing binary stars. The data of variable stars are read from several catalogue files. It is intended to be used off-line, no internet connection is required at run-time. The current version works in the MS Windows 98 SE, 2000, X...
Julian date calculator & calendar (AAVSO)
Variable star observations reported to the AAVSO must be expressed either in terms of Universal Time (UT) or Julian Day (JD) and the decimal part of the day given in Greenwich Mean Astronomical Time (GMAT).
JD is the standard unit of time used by astronomers because it is convenient and unambiguou...
Lew Cook’s HJD calculator
Enter the RA and Dec of the target star (J2000), and the date and time UT. It outputs the Julian Date, heliocentric correction, and Heliocentric Julian Date. Note for nearly all purposes you can take the heliocentric correction for a given star, on a given night, as constant. Just find it for the mi...
Local apparent sidereal time
USNO publish Michael Richmond’s calculator for local apparent sidereal time.
Sidereal time is the hour angle of the vernal equinox, the ascending node of the ecliptic on the celestial equator. The daily motion of this point provides a measure of the rotation of the Earth with respect to the stars,...