Standard headers

The standard names and types (which can be generated by hfix ) are as follows: (C=CHARACTER,D=DOUBLE PRECISION,I=INTEGER,R=REAL) 
  R Dwell         -- Exposure time in seconds.
  I Night         -- Night number of observing run
  I Record        -- Record or run number of exposure
  I Day           -- Day of month
  I Month         -- Month
  I Year          -- Year
  D UTC           -- UT at centre of exposure
  D HJD           -- Heliocentric Julian date at centre of exposure
  D RJD           -- Julian date at centre of exposure (I don't know why theres an "R")
  D Delay         -- RJD-HJD (heliocentric correction) in days
  D Sidereal time -- Sidereal time of observation in hours.
  D Hour angle    -- Hour angle of observation in hours
  D Airmass       -- Airmass at centre of observation.
  D RA            -- Right ascension of object (decimal hours)
  D Dec           -- declination of object (decimal degrees)
  D Equinox       -- Equinox of coordinates
  D Gal longitude -- Galactic longitude
  D Gal latitude  -- Galactic latitude
  D Airmass       -- Airmass at mid-point of observation.
  C Object        -- Object name
  D Longitude     -- Longitude of observing site (degrees)
  D Latitude      -- Latitude of observing site  (degrees)
  D Height        -- height of site in metres
  C Site          -- Name of site
  D Vearth        -- Vtrue = Vobs - Vearth (km/s)
In addition several phases can be specified. The orbital phase may be set by hfix if an ephemeris is available, otherwise use the command PHASE. All of the phases are treated in the same manner, but for convenience there are several specific names (spin, beat and hump) which can be associated with phases required for CV studies. You can invent your own name for a phase but it will not necessarily be averaged correctly when combining spectra. Three non-specific names (phase1, phase2 and phase3) are treated correctly. The command 'PHASE' will also store the ephemeris used to define the phase as Zero?, Period?, Pdot? where ? = O,S,B,H,1,2, or 3. 
  D Orbital phase -- Orbital phase of a binary 
  D Spin phase    -- Spin phase (e.g. for intermediate polars) 
  D Beat phase    -- Beat phase again for intermediate polars 
  D Hump phase    -- Superhump phase for SU UMa stars
  D Phase1        -- User defined phases which are correctly
  D Phase2        -- treated by routines such as the average 
  D Phase3        -- and phase bin commands.
Tom Marsh, Warwick.