Michigan State UniversityObservatory

For Astronomers

Sky Conditions

Dark sky forecast

CCD specifications

  • Camera: Apogee Alta U47
  • Array Size: 1024 × 1024 pixels
  • Pixel Size: 13 × 13 μm
  • Read Noise: 9 e-
  • Cooling: Thermoelectric system with forced air
  • Dark Current: ≈0.1–0.2 e-/pix/s; depends on CCD temperature

Telescope Specifications

  • Coordinates: 42° 42’ 23” North, 05h 37m 56s West
  • Elevation site/telescope: 866 ft/896 ft above sea level
  • Telescope Manufacturer: Boller and Chivens Division, Perkin-Elmer Corporation
  • Guide telescope:
    • Aperture: 6"
    • Focal Ratio: f/15
    • Focal length: 90 in
    • Faintest Visible Magnitude: 12.7
    12 mm eyepiece24 mm eyepiece
    Magnification190×95×
    Field of view13’26’
  • Primary Mirror
    • Aperture: 24” (clear aperture)
    • Focal Ratio: f/3.0 paraboloid
    • Optical Material: Cer-Vit
    • Focal length: 72 in
    • Faintest Visible Magnitude: 15.7
  • Seconday Mirror: f/8.0 Cassegrain
    • Effective focal length: 192”
    • Field diameter: 60.0’
    • Approx. magn. with Erfle eyepiece: 175×
    • Approx. FOV with Erfle eyepiece: 28’
    • Field Flattener: Yes
    • 2nd Mirror Aperture: 9.14”
    • 2nd Mirror Focal Length: -39.91”
    • Plate scale: 42.3 ”/mm
  • Focusing: Electronic drive at secondary mirror
  • Optical quality: 80% of the light from an on-axis pt. source images within a circle .5” dia. at any of three foci
  • Mirror coating: Aluminized with a magnesium fluoride overcoat
  • Optical configurations: f/8 Cassegrain
  • Type of Mount: Equatorial off-axis
  • Telescope weight: 6000 pounds
  • Slew drive rate: 4° per second
  • Guide and set drive rate: Servo controlled variable
  • Tracking drive gear: 3 in diameter, 360 teeth
  • Tracking accuracy: 2” per 5 min; 5” per hr
  • Position setting accuracy: RA: .01m; Dec: .1’
  • Other secondary mirrors:
    f/13.5 Cassegrainf/34.6 Coude
    Effective focal length324”830”
    Field diameter31.8’24.9’
    Approx. magn. with Erfle eyepiece295×
    Approx. FOV with Erfle eyepiece17’
    Field FlattenerNoNo
    2nd Mirror Aperture6.07”8.50”
    2nd Mirror Focal Length-21.39”27.32”
    Plate scale25.1 ”/mm09.8 ”/mm