bruce@ssc-vax.UUCP (Bruce Stock) (03/03/85)
This file contains a description of a reduce version of the YALE Catalog of Bright Stars. It is a computer readable list of data for some 9000 stars. The original catalog contained a very large amount of data for each star, so much so that the data file was almost 3 megabytes! The original data has been filtered (data was removed) so that the reduced catalog occupies only about 270k. The original catalog contained a 200 byte entry for each star. This has been reduced to a 29 byte entry for each star by eliminating many of the references to other catalog numbers for each star and other data. The data on each star is: epoch 2000 Right Asen. (6 digits), Declination (sign plus 4 digits), Magnitude (4 digits), Color ( 4 digits), Proper Motion in R.A. (5 digits), and Proper Motion in Dec. The following program extracts data from one of the data files and plots it on a Z100 monochrome screen in appropriate intensity levels. (Note: for this program the data was broken into 9 subfiles of approx equal length. A complete program would automatically determine the proper subfile.) 10 REM Use the following data values for input on your first try: 11 REM 3,6 12 REM -15,15 13 REM This should show a star field with constellation Orion at left side 14 REM of the screen. 50 CLS 60 INPUT "Minimum and Maximum Right Ascension "; RAMIN,RAMAX 70 INPUT "Minimum and Maximum Declination "; DECMIN, DECMAX 80 DECMIN=DECMIN+90 : DECMAX= DECMAX +90 100 CLS 130 OPEN "I",#1,"B:STAR2" 132 INPUT #1,A$ 134 A = VAL(A$) 136 REM 640x225 represents Z100 screen width, height 138 KRA= 640/(RAMAX - RAMIN): KDEC= 225/(DECMAX - DECMIN) 150 FOR I = 1 TO A 260 INPUT #1,A$ 300 RA= VAL(MID$(A$,1,2)) + VAL(MID$(A$,3,2))/60 + VAL(MID$(A$,5,2))/3600 310 DEC = VAL(MID$(A$,8,2)) + VAL(MID$(A$,10,2))/60 315 MAG = VAL(MID$(A$,12,4))/100 320 IF MID$(A$,7,1) = "-" THEN DEC = 90-DEC ELSE DEC = 90+DEC 330 IF (RA < RAMIN ) THEN 380 340 IF (DEC < DECMIN) OR (DEC > DECMAX) THEN 380 350 X=640- (RA-RAMIN)*KRA 360 Y=225- (DEC-DECMIN)*KDEC 361 IF MAG >6.5 THEN PSET(X,Y),1 362 IF (MAG =>5.5) AND (MAG=<6.5) THEN PSET(X,Y),4 363 IF (MAG =>4.5) AND (MAG=<5.5) THEN PSET(X,Y),2 364 IF (MAG =>3.5) AND (MAG=<4.5) THEN PSET(X,Y),6 365 IF (MAG =>2.5) AND (MAG=<3.5) THEN PSET(X,Y),7 366 IF (MAG =>1.5) AND (MAG=<2.5) THEN CIRCLE(X,Y),1,,,,.7 :PSET(X,Y),7 367 IF (MAG =>.5) AND (MAG=<1.5) THEN CIRCLE(X,Y),2,,,,.4 : PAINT(X,Y),7,7 370 IF MAG <.5 THEN CIRCLE(X,Y),3,,,,.5 : PAINT(X,Y),7,7 375 IF RA>RAMAX THEN 900 380 NEXT 900 CLOSE 950 BEEP 1000 GOTO 1000 The YALE CATALOGUE OF BRIGHT STARS is in the public domain. ***************************************************************** A byte-by-byte description of the contents of the catalogue is given below. The information in the "Description" column is derived mainly from the published version of the catalogue whenever possible. The "Suggested Format" column is for FORTRAN-formatted reads. ***** Right Ascension (epoch 2000.0) ***** Hours I2 Minutes I2 Seconds I2 ***** Declination (epoch 2000.0) ***** Sign A1 Degrees I2 Minutes I2 ***** Visual Magnitude ***** Sign A1 (if minus (-) magnitude) Visual Magnitude I3 (unit = 0.01 magnitude) ***** Color ***** Sign A1 B-V in UBV System I3 (unit = 0.01 magnitude) ***** Annual Proper Motion in Right Asen. ***** Sign A1 Value I4 (unit = 10^-3 arcsec) ***** Annual Proper Motion in Declination ***** Sign A1 Value I4 (unit = 10^-3 arcsec)