SKY(7) (bowell) SKY(7) NAME sky - astronomical ephemeris SYNOPSIS sky [ -l ] DESCRIPTION Sky predicts the apparent locations of the sun, moon, visi- ble planets, and stars brighter than magnitude 2.5. It reads one line from the standard input to obtain the desired time expressed as five numbers: year, month, day, hour, and minute in GMT. An empty line means now. Each object is printed with astronomical coordinates, azimuth-elevation coordinates relative to Murray Hill, NJ, and magnitude. For variable stars the maximum magnitude is printed with `*'. Option -l causes sky to prompt for another viewing location. Standard astronomical effects are accounted for: nutation and precession of the equinox, annual aberration, diurnal parallax, and proper motion. Atmospheric effects (extinc- tion and refraction) are not calculated, nor is perturbation of the earth by other bodies. In ephemeris (slighly different from civil) time, the pro- gram yields positions of sun, moon, and stars good to a few tenths of an arc-second. Planets are good to a few seconds. FILES SEE ALSO scat(7) American Ephemeris and Nautical Almanac and Explanatory Sup- plement to the American Ephemeris and Nautical Almanac