Calendars and Calculators
The tools and information linked from this page will be useful for all the aspects of observations that are related to the position of the target: their visibility, sun- and moon-rise and -set, ephemerides for Solar System minor bodies, etc.
Ephemerides
- Calculation of Site Sky Ephemerides
This tool produces a nightime calendar of phenomena for a single site. - Solar System Ephemerides: IMCCE service hosted through ESO Moving Targets Procedures page
The IMCCE service provides the same data in PAF format that needs to be used for ESO Observing Blocks preparation. - Object Observability
This tool provides object observability tables based on site, object coordinates and observing period. - Daily Almanac
This tool produces almanac data for a single site and for a single date. Provided by courtesy of J. Thorstensen and B. Casey.
Position, Airmass, Extinction
- Object Visibility - STARALT (ING)
draw the airmass curves for a list of objects, for a given night - Extinction coefficients for La Silla (old Danish 1.54m page)
- Differential atmospheric refraction table for the La Silla and Paranal sites.
The differential atmospheric refraction is calculated in arcseconds, at an altitude of 2 km, as function of wavelength and airmass. A new calculator is being worked on and will go into the infrared.
ETCs and Units Conversion
- Exposure Time Calculators
- ESO's SkyCalc (the Sky Model calculator, that also includes an Almanac)
- Magnitude/Flux Density Converter (from NASA/IPAC Infrared Science Archive)