term% cat index.txt ASTRO(7) Miscellaneous Information Manual ASTRO(7)
NAME
astro - print astronomical information
SYNOPSIS
astro [ -dlpsatokm ] [ -c n ] [ -C d ] [ -e obj1 obj2 ]
DESCRIPTION
Astro reports upcoming celestial events, by default for 24 hours start‐
ing now. The options are:
d Read the starting date. A prompt gives the input format.
l Read the north latitude, west longitude, and elevation of the
observation point. A prompt gives the input format. If l is
missing, the initial position is read from the file
/lib/sky/here.
c Report for n (default 1) successive days.
C Used with -c, set the interval to d days (or fractions of days).
e Report distance between the centers of objects, in arc seconds,
during eclipses or occultations involving obj1 and obj2.
p Print the positions of objects at the given time rather than
searching for interesting conjunctions. For each, the name is
followed by the right ascension (hours, minutes, seconds), dec‐
lination (degrees, minutes, seconds), azimuth (degrees), eleva‐
tion (degrees), and semidiameter (arc seconds). For the sun and
moon, the magnitude is also printed. The first line of output
presents the date and time, sidereal time, and the latitude,
longitude, and elevation.
s Print output in English words suitable for speech synthesizers.
a Include a list of artificial earth satellites for interesting
events. (There are no orbital elements for the satellites, so
this option is not usable.)
t Read ÎT from standard input. ÎT is the difference between
ephemeris and universal time (seconds) due to the slowing of the
earth's rotation. ÎT is normally calculated from an empirical
formula. This option is needed only for very accurate timing of
occultations, eclipses, etc.
o Search for stellar occultations.
k Print times in local time (‘kitchen clock') as described in the
timezone environment variable.
m Includes a single comet in the list of objects. This is modi‐
fied (in the source) to refer to an approaching comet but in
steady state usually refers to the last interesting comet (cur‐
rently Hale-Bopp, C/1995 O1).
FILES
/lib/sky/estartab
ecliptic star data
/lib/sky/here
default latitude (N), longitude (W), and elevation (meters)
SOURCE
/sys/src/cmd/astro
SEE ALSO
scat(7)
BUGS
The k option reverts to GMT outside of 1970-2036.
ASTRO(7)