Welcome to the SBO

Astrophysical & Planetary Sciences


Coordinates of 24in Telescope

Latitude +40 deg 00' 13.4" (40.00372 degrees North)

Longitude +105 deg 15' 45.0" (105.2635 degrees West)

Altitude 1653 meters (5423 feet ASL)

Geographic Latitude - The telescope is slightly over 1/4 mile (1,357 feet) north of the Earth's 40th Parallel of Latitude (the street named Baseline which runs east-west through the southern portion of the city of Boulder).

Observatory Code - Sommers-Bausch Observatory is now listed with the IAU and MPC with an Observatory Code of 463. SBO users who file a report with the International Astronomical Union or its Minor Planet Center should include the code for identification.

Sidereal Time - The Observatory lies 7 hours, 1 minute, 3.24 seconds of time west of the Prime Meridian, hence our Local Sidereal Time trails that of Greenwich England by 7h 1m 3s.

Mean Solar Time - Our Local Mean Solar Time lags behind Mountain Standard Time (mean time at the 105th meridian) by 63 seconds. Subtract 1 minute and 3 seconds from the civil timezone MST to obtain the Local Mean Solar Time at SBO.

Local Apparent Solar Time Or "sundial time", is the true solar time at our location equal to the hour angle of the Sun (plus 12 hours since LAST begins at midnight rather than noontime). From your adjustment for Mean Solar Time, subtract the appropriate value from the Equation of Time chart to obtain the SBO Local Apparent Solar Time.


Astronomy Day 2016

Saturday April, 23

Sommers-Bausch Observatory and Fiske Planetarium have will opened their doors to the public for a FREE, day-long CU Astronomy Day celebration.

Activities at the Observatory include explorations of the electromagnetic spectrum, general astronomy activities and demonstrations, and hands-on astronomical observations. During daylight hours, members of the Boulder Astronomy and Space Society help budding young astronomers learn about amateur astronomy and what kind of telescope to buy. After dark, there is stargazing (weather permitting) with both the BASS and Observatory telescopes.

Fiske Planetarium offers a variety of displays, activities and demonstrations including rocket launches, live talks, starshow mini-presentations, Science on a Sphere explorations of the Earth and the solar system, and concludes each year with a special evening planetarium presentation. Local amateur and professional astronomy vendors, as well as a food court, are also present.