PPM Catalog Binary Header Format

The first 28 bytes of both PPM and PPMra contain the following information:
Integer*4 STAR0=0	Subtract from star number to get sequence number
Integer*4 STAR1=1	First star number in file
Integer*4 STARN=378910	Number of stars in file
Integer*4 STNUM=1	0 if no star i.d. numbers are present
			1 if star i.d. numbers are in catalog file
			2 if star i.d. numbers are  in file
Logical*4 MPROP=t	True if proper motion is included
			False if no proper motion is included
Integer*4 NMAG=1	Number of magnitudes present
Integer*4 NBENT=28	Number of bytes per star entry (PPM)
*Integer*4 NBENT=32	Number of bytes per star entry (PPMra)