'******************************************************
'*    This program caculates the absolute stellar     *
'*     based on relative magintude and distance       *
'* -------------------------------------------------- *
'* SAMPLE RUN:                                        *
'*                                                    *
'* To calculate absolute stellar magnitude:           *
'* Give relative mag. and distance in parsecs: 10, 3  *
'*                                                    *
'* A star with relative magnitude  10                 *
'* at a distance of  3  parsecs                       *
'* has an absolute magnitude of  12.61                *
'*                                                    *
'* -------------------------------------------------- *
'* Ref.: "Problem Solving with Fortran 90 By David R. *
'*        Brooks, Springer-Verlag New York, 1997".    *
'*                                                    *
'*               Basic Release By J-P Moreau, Paris.  *
'*                        (www.jpmoreau.fr)           *
'******************************************************
' Explanations;
' ------------
'   The absolute magnitude M of a star is related to its
' relative magnitude m and and the distance to a star r,
' measured in parsecs, where 1 parsec = 3.26 light years,
' by the equation:
'
'                  M = m + 5 - 5 log10(r)
'
'   According to this equation, a star with a relative
' magnitude of +1 at a distance of 10 parsecs has an
' absolute magnitude of +1. The larger the magnitude, the
' dimmer the star. Sirius is a very bright star with a
' relative magnitude of -1.58. Stars visible to the naked
' eye range mostly from about +1 to +6 in relative magni-
' tude.
'   The dimmest star that can be seen with the 200-inch
' Hale telescope has a magnitude of about +23.
'-------------------------------------------------------- 
  CLS
  PRINT
  PRINT " To calculate absolute stellar magnitude:"
  INPUT " Give relative mag. and distance in parsecs: ", relmag, parsecs
  
  absmag = relmag + 5! - 5! * LOG(parsecs) / 2.302585

  F$ = "###.##"

  PRINT
  PRINT " A star with relative magnitude "; relmag
  PRINT " at a distance of "; parsecs; " parsecs"
  PRINT " has an absolute magnitude of ";
  PRINT USING F$; absmag
  PRINT


END

'end of file starmag.bas