OF THE ROGER N. CLARK

VISUAL ASTRONOMY OF THE DEEP SKY
Table F.S (cont. )
APPENDIX F: OPTIMUM DETECTION MAGNIFICATIONS FOR DEEP-SKY OBJECTS
Table F.S (cont. )
write (crtout , 102) size1 , size2, sb, mb , sbp , sbm
102 format (' Ob ject size: ' ,f8 .2,· by ' ,f8 .2,' arc minutes' ,/,
1 ' surface brightness (magnitudes / sq . arc-sec.):',/,
2 5x,'object with no telescope : ',f7.1,/,
3 5x,'reduction due to ODM : ',f7. 1,/,
4 5x,'object in telescope at ODM : ',f7.1,/,
5 5x,'background in tele scope at ODM: ' ,f7.1,
6 /)
wr ite (crtout ,104) odm
104 format (. ODM: ' ,i6, 'x' ,/)
wr ite (crtout , 106) cl, xc
106 format (' Log object contrast : ',f5.1,/,
1 ' Log threshold cont ra st : ' , f 5 .1)
if (cl .It. xc) then
write (crtout , 115)
115 format (' The CONTRAST IS TOO LOW TO DETECT '
1 'the object ',/)
else
write (crtout , 120)
120 format (' The object is detectable ' ,/)
endif
2000
go to 1
stop
end
c---------------------------------------------------
c
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c
real*4 function thrcon (angle,sb)
implicit integer*4 (i-n)
this function computes the contrast threshold for a given angle
by two dimensional interpolation.
angle = angle in arc-minutes
sb = surface "brightness
angx = log10 angles (arc-min) data for 7 values of contrast
sbx = log base 10 cont rast for angx va lues for each surface
brightness ranging from 4 to 27 mag/arc-sec
angx and sbx are used to interpolate to the thrcon given
by ang .
real*4 angx(7) , sbx(7,24) , angle, sb
real*4 sbx1 (7), sbx2(7) , sbx3(7), sbx4(7) , sbx5( 7), sbx6(7)
real*4 sbx7(7), sbx8(7) , sbx9(7), sbx10(7), sbx1 1(7), sbx12( 7)
real*4 sbx13(7), sbx14(7) , sbx15(7), sbx16(7), sbx17(7)
real*4 sbx18(7) , sbx19(7) , sbx20(7) , sbx21(7), sbx22 (7)
real*4 sbx23(7) , sbx24(7)
equivalence (sbx1(1),sbx(1,1»
_ equivalence (sbx2( 1),sbx( 1,2»
equivalence (sbx3( 1),sbx( 1,3»
equivalence (sbx4( 1),sbx( 1,4»
equivalence (sbx5( 1),sbx( 1,5»
equivalence (sbx6(1),sbx( 1,6»
equivalence (sbx7( 1),sbx( 1,7»
equivalence (sbx8( 1),sbx( 1,8»
equivalence (sbx9(1),sbx(1,9»
equivalence (sbxlO(l),sbx( l,lO»
equivalence (sbxll(l),sbx (l ,ll»
equivalence (sbxI2(1),sbx(I,12»
equivalence (sbxI3(1),sbx(I,13»
equivalence (sbxI4(1),sbx( I,14»
equivalence (sbx15(1),sbx ( 1,15»
equivalence (sbx16(1),sbx(1,16»
equivalence (sbx17( 1),sbx(1,17»
equivalence (sbx18( 1),sbx( 1,18»
equivalence (sbx19( 1),sbx (1,19»
equivalence (sbx20( 1),sbx (1,20»
equivalence (sbx21 (1),sbx( 1,21»
equivalence (sbx22(1),sbx (1,22»
equivalence (sbx23( 1),sbx(1,23»
equivalence (sbx24(1),sbx (I,24»
data angx /-0 .2255,0.5563,0.9859 ,1.260 1 ,1.7419,2.0828 ,2.5563/
c: ::::: : : : : : :::
c mag/arc-sec =4
c : : : : : : : : : : : : : :
data sbxl/ -0.37691 1, - 1.806444 , -2 .336825,-2 .4 60093 ,
1 - 2.546943,-2 .560968, - 2.565971/
c: ::::: :::: ::: :
c mag/arc-sec =5
c: :: :: :: : : : : : : :
data sbx2/ -0.331451, - 1.7 74717,-2.333688,-2.460781 ,
1 - 2.546521,-2.560729 , -2.565756/
c: ::::: ::: : ::::
c ma g/arc-sec =6
c: :::: :: ::: :: : :
data sbx3/ -0 .268183 ,-1 . 734482 , -2.331011,-2 .460521 ,
- 2.546681 ,-2.560819 ,-2.565837/
c: :: : : : : : : : : : ::
c mag/a rc-sec =7
c: :: : : : : : : : :: : :
data sbx4/-0.198177 ,-1 .685101,-2.3139 51 , -2 .457228 ,
-2.548051 , -2 .561 529 , -2 .566460/
c: :: : : : : : : : : : : :
c mag /arc-sec =8
c: :: :: :: :: : : : : :
data sbx5/ -0 .1238 15,- 1.6 25192 , -2.2791 19,-2.446245,
- 2.546321 ,-2.559690 ,-2.564570/
342
343