Instrument Host Overview
  ========================
  The 'LOWELL' instrument host is used when it is not possible to
  determine which of the various available telescopes at Lowell
  Observatory were used in making the observations associated with
  a data set.
 
  The following table gives the specifications of the various Lowell
  Observatory telescopes.
 
            Perkins   Hall 42in  Hall 42in
              72in      F/16        F/8      31in        21in
           =========  =========  =========  =========  ==========
 
 Longitude  111d 32'  111d 32'   111d 32'    111d 32'    111d 39'
             09.3in     07.9in     07.9in    09.0in      59.2in
 
 Latitude   +35d 05'  +35d 05'   +35d 05'    +35d 05'    +35d 12'
             48.6in     48.3in     48.3in   54.6in      10.4in
 
 Altitude   7236ft.    7236ft.    7236ft.   7243ft.     7260ft.
            (2206m)    (2206m)    (2206m)   (2208m)     (2213m)
 
    Dp     72in(1.8m)42in(1.1m) 42in(1.1m)  31/29.5in    20.78
                                           (0.79/0.75m)  (0.53m)
   F/#        17.5      16.0        8.0      15.7        15.9
 
    EFI     1256.5in    669in      334in      464in      332.5in
           (31.93cm)  (16.99cm)  (8.48cm)   (11.78cm)    (8.44cm)
   Scale
  (in/mm)      6.45      12.1       24.3        17.5        24.3
 
   BFI       51.5in      25in       25in       25in        20in
            (1.30cm)  (0.63cm)   (0.63cm)   (0.63cm)    (0.51cm)
   Fp/#       4.18       4.0        4.0        5.0         3.4
 
    FLp      300.6in    168in      168in      155in      70.0in
           (7.635cm)  (4.267cm)  (4.267cm)   (3.94cm)   (1.77cm)
 
   Dsa       16.3in     9.7in      16.2in     9.0in        4.6in
            (0.41m)    (0.25m)    (0.41m)    (0.22m)      (0.12m)
 
    Is       284.1in   154.3in    128.4in      134.9in     72.7in
            (7.22m)    (3.92m)    (3.26m)     (3.43m)     (1.85m)
 
    Os       68.0in     38.7in     64.6in      45.1in       15.3in
            (1.72m)    (0.98m)    (1.64m)     (1.14cm)     (0.39m)
 
    Ms       232.6in   129.3in    103.4in      109.9in     54.7in
            (5.91m)    (3.28m)    (2.63m)     (2.79m)     (1.39m)
    mag       4.2        4.0        2.0        3.0         4.7
    K1        -1.0      -2.32      -2.32       -1.00       -1.00
    K2       -3.65      -5.96     -16.84       -5.01       -3.35
 
  Notes:
 
   1) Longitude and latitude are good to about +/- 0.2.
   2) The altitudes are good to about +/- 1 meter.
   3) The Hall F/16 is not a true Cassegrain telescope since the primary
      is a hyperboloid.
   4) The Hall F/8 is a Ritchey-Chretien telescope.
   5) The 31 inch primary is F/5. However, it is stopped down to 29.5
      inches.
   6) Only the Hall F/8 has a known optimum back focal distance.
   7) The conic constant is defined such that 0 is a circle and -1 is a
      parabola.
   8) DSA is the diameter of the axial cone at the secondary. The diameter
      of the secondary is 1 to 2 inches larger than DSA.
 
 
  Lowell Observatory currently maintains an informational World Wide Web
  site at http://www.lowell.edu/.