123 lines
2.4 KiB
Plaintext
123 lines
2.4 KiB
Plaintext
|
.TH ASTRO 7
|
||
|
|
.SH NAME
|
||
|
|
astro \- print astronomical information
|
||
|
|
.SH SYNOPSIS
|
||
|
|
.B astro
|
||
|
|
[
|
||
|
|
.B -dlpsatokm
|
||
|
|
]
|
||
|
|
[
|
||
|
|
.B -c
|
||
|
|
n
|
||
|
|
]
|
||
|
|
[
|
||
|
|
.B -C
|
||
|
|
d
|
||
|
|
]
|
||
|
|
[
|
||
|
|
.B -e
|
||
|
|
.I obj1
|
||
|
|
.I obj2
|
||
|
|
]
|
||
|
|
.SH DESCRIPTION
|
||
|
|
.I Astro
|
||
|
|
reports upcoming celestial events, by default for 24 hours starting now.
|
||
|
|
The options are:
|
||
|
|
.TP
|
||
|
|
.B d
|
||
|
|
Read the starting date.
|
||
|
|
A prompt gives the input
|
||
|
|
format.
|
||
|
|
.TP
|
||
|
|
.B l
|
||
|
|
Read the north latitude, west longitude, and elevation of the observation point.
|
||
|
|
A prompt gives the input format.
|
||
|
|
If
|
||
|
|
.B l
|
||
|
|
is missing, the initial position is read from the file
|
||
|
|
.BR /lib/sky/here .
|
||
|
|
.TP
|
||
|
|
.B c
|
||
|
|
Report for
|
||
|
|
.I n
|
||
|
|
(default 1) successive days.
|
||
|
|
.TP
|
||
|
|
.B C
|
||
|
|
Used with
|
||
|
|
.BR -c ,
|
||
|
|
set the interval to
|
||
|
|
.B d
|
||
|
|
days (or fractions of days).
|
||
|
|
.TP
|
||
|
|
.B e
|
||
|
|
Report distance between the centers of
|
||
|
|
objects, in arc seconds, during eclipses or occultations involving
|
||
|
|
.I obj1
|
||
|
|
and
|
||
|
|
.IR obj2 .
|
||
|
|
.TP
|
||
|
|
.B 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),
|
||
|
|
declination (degrees, minutes, seconds),
|
||
|
|
azimuth (degrees),
|
||
|
|
elevation (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.
|
||
|
|
.TP
|
||
|
|
.B s
|
||
|
|
Print output in English words suitable for speech synthesizers.
|
||
|
|
.TP
|
||
|
|
.B 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.)
|
||
|
|
.TP
|
||
|
|
.B t
|
||
|
|
Read
|
||
|
|
ΔT
|
||
|
|
from standard input.
|
||
|
|
ΔT
|
||
|
|
is the difference between ephemeris and
|
||
|
|
universal time (seconds) due to the slowing of the earth's rotation.
|
||
|
|
ΔT
|
||
|
|
is normally calculated from an empirical formula.
|
||
|
|
This option is needed only for very accurate timing of
|
||
|
|
occultations, eclipses, etc.
|
||
|
|
.TP
|
||
|
|
.B o
|
||
|
|
Search for stellar occultations.
|
||
|
|
.TP
|
||
|
|
.B k
|
||
|
|
Print times in local time (`kitchen clock')
|
||
|
|
as described in the
|
||
|
|
.B timezone
|
||
|
|
environment variable.
|
||
|
|
.TP
|
||
|
|
.B m
|
||
|
|
Includes a single comet in the list of objects.
|
||
|
|
This is modified (in the source) to refer to an approaching comet
|
||
|
|
but in steady state
|
||
|
|
usually refers to the last interesting comet (currently Hale-Bopp, C/1995 O1).
|
||
|
|
.SH FILES
|
||
|
|
.TF /lib/sky/estartab
|
||
|
|
.TP
|
||
|
|
.B /lib/sky/estartab
|
||
|
|
ecliptic star data
|
||
|
|
.TP
|
||
|
|
.B /lib/sky/here
|
||
|
|
default latitude (N), longitude (W), and elevation (meters)
|
||
|
|
.SH SOURCE
|
||
|
|
.B /sys/src/cmd/astro
|
||
|
|
.SH SEE ALSO
|
||
|
|
.IR scat (7)
|
||
|
|
.SH BUGS
|
||
|
|
The
|
||
|
|
.B k
|
||
|
|
option reverts to GMT outside of 1970-2036.
|