astro.1 (2428B)
1 .TH ASTRO 1 2 .SH NAME 3 astro \- print astronomical information 4 .SH SYNOPSIS 5 .B astro 6 [ 7 .B -dlpsatokm 8 ] 9 [ 10 .B -c 11 n 12 ] 13 [ 14 .B -C 15 d 16 ] 17 [ 18 .B -e 19 .I obj1 20 .I obj2 21 ] 22 .SH DESCRIPTION 23 .I Astro 24 reports upcoming celestial events, by default for 24 hours starting now. 25 The options are: 26 .TP 27 .B d 28 Read the starting date. 29 A prompt gives the input 30 format. 31 .TP 32 .B l 33 Read the north latitude, west longitude, and elevation of the observation point. 34 A prompt gives the input format. 35 If 36 .B l 37 is missing, the initial position is read from the file 38 .BR \*9/sky/here . 39 .TP 40 .B c 41 Report for 42 .I n 43 (default 1) successive days. 44 .TP 45 .B C 46 Used with 47 .BR -c , 48 set the interval to 49 .B d 50 days (or fractions of days). 51 .TP 52 .B e 53 Report distance between the centers of 54 objects, in arc seconds, during eclipses or occultations involving 55 .I obj1 56 and 57 .IR obj2 . 58 .TP 59 .B p 60 Print the positions of objects at the 61 given time rather than searching for interesting 62 conjunctions. 63 For each, the name is followed by 64 the right ascension (hours, minutes, seconds), 65 declination (degrees, minutes, seconds), 66 azimuth (degrees), 67 elevation (degrees), 68 and semidiameter (arc seconds). 69 For the sun and moon, the magnitude is also printed. 70 The first line of output presents the date and time, 71 sidereal time, and the latitude, longitude, and elevation. 72 .TP 73 .B s 74 Print output in English words suitable for speech synthesizers. 75 .TP 76 .B a 77 Include a list of artificial earth satellites for interesting events. 78 (There are no orbital elements for the satellites, so this option 79 is not usable.) 80 .TP 81 .B t 82 Read 83 ΔT 84 from standard input. 85 ΔT 86 is the difference between ephemeris and 87 universal time (seconds) due to the slowing of the earth's rotation. 88 ΔT 89 is normally calculated from an empirical formula. 90 This option is needed only for very accurate timing of 91 occultations, eclipses, etc. 92 .TP 93 .B o 94 Search for stellar occultations. 95 .TP 96 .B k 97 Print times in local time (`kitchen clock') 98 as described in the 99 .B timezone 100 environment variable. 101 .TP 102 .B m 103 Includes a single comet in the list of objects. 104 This is modified (in the source) to refer to an approaching comet 105 but in steady state 106 usually refers to the last interesting comet (currently Hale-Bopp, C/1995 O1). 107 .SH FILES 108 .TP 109 .B \*9/sky/estartab 110 ecliptic star data 111 .TP 112 .B \*9/sky/here 113 default latitude (N), longitude (W), and elevation (meters) 114 .SH SOURCE 115 .B \*9/src/cmd/astro 116 .SH SEE ALSO 117 .MR scat (1) 118 .SH BUGS 119 The 120 .B k 121 option reverts to GMT outside of 1970-2036.