General Information on the VATT

     Optical System             : aplanatic Gregorian, f/9
     Focal Length               : 16.48 m
     Primary Mirror             : f/1.0, Diameter 1.83 meters
     Secondary Mirror           : f/0.9, Diameter 0.38 meters
     Back Focal Distance        : 50.80 mm (effective)
     Vignetting-Free Field      : 72 mm diameter (15 arcmin)
     Image Scale                : 12.52 arcsec/mm
     Image quality              : 0.1 arcsec throughout 6.8 arcmin
                                     diameter flat FOV
     Mount                      : altitude-azimuth with derotator


Geographical Location of VATT

     Latitude  : 32 42' 04.69" N         
     Longitude : 109 53' 31.25" W
     Altitude  : 3191 meters
     Driving time from Tucson  :  3.5 hours in good conditions

     IAU Observatory Code number :  290
	 
	 
	 
Sky Conditions at VATT
	 
	 The sky surface brightness for low-airmass (sec z < 1.2) observations
	 averaged 22.00, 22.53, 21.49, and 20.88 mag arcsec2 in U, B, V, and R,
	 respectively.  These were measured during relatively high solar activity.
	 The darkest run achieved 21.72 in V, close to theoretical minimum of
	 22.0 mag arcsec2.
	 
	 The FWHM seeing for median R-band focus images per run ranged from 0.97"
	 to 2.15", with values occasionally as low as 0.65".  While this is very
	 good, please note that the VATT's height and location do not give the best
	 seeing achievable at MGIO.
	 
	 (These values were determined by Violet Taylor, ASU)
     


Computer Systems at VATT

     Sun SparcUltra Workstation
         with 320 MB RAM and 9 GB hard disk
         DAT (dds-1) tape drive
         TCP/IP link to the Steward Obs. network via DS3
            microwave connection

     Linux Box for TCS interface, Xephem utility, and autoguider control

     VME instrument computer running VxWorks

     IRAF reduction software and ICE data aquisition software

     PCs
       Pentium II PC with Linux and NT