Open House

Friday Night Telescope Observing
Every Clear Friday Night
When CU courses are in session

Summer 2017 Schedule

2017 Printable Schedule

General Information

Free Public Open Houses are held on Sommers-Bausch Observatory's Observing Deck on Friday evenings (weather permitting) throughout the Spring, Summer, and Fall Semesters whenever the University of Colorado is in session. Starting times are at 9:00 pm during the summer since the Sun sets so late with Daylight Savings Time in effect.

The program at the Observatory is informal: you can stop by anytime after we open and stay as long as you wish (or until we drive you out!). Sessions typically last from 1 hours to 3 hours, depending upon the weather, the quality of the night, and the enthusiasm and size of the crowd (if unsure of observing status call 303-492-2020). There is no charge for the Observatory's Open House nights ... the stars are free to everyone!

We also have tripod-mounted binoculars and the world's largest starwheel (well, at least we think it is) for identifying bright stars and constellations. Depending upon the staffing on a particular night, we may be able to offer you a chance to visit the 24-inch telescope ... that mysterious tube hiding hiding inside the dome ... as well additional smaller telescopes set up on the open deck for looking at the Moon and other bright celestial objects.

Most of our evening programs are hosted by the APS Department's graduate students, with an occasional faculty professor, researcher, local amateur astronomer, and/or undergraduate volunteer on hand as well. If you'd like to find out who will be on deck any particular night, here's the list of Open House Hosts for the current semester.

Who's Invited?

Anybody and everybody: individuals, students, families, and groups - are all welcome. Generally reservations are not required, except as noted below.

Groups of 8 or more individuals planning on attending the SBO Open House are asked to make reservations by calling 303-492-6732 at least three days in advance. That way, we can inform your hosts for the evening that a larger than average crowd may be expected, and they can plan on putting together a stargazing program that will address your group's age levels and interests.

Weather Considerations

The telescopes are outside in an unheated area - so be sure to dress appropriately and warmly!

Telescopes are not magical instruments - they can't see through clouds! If it's overcast, we won't be able to show you anything in the sky. Usually however, unless the weather is truly bad, we'll be around for at least 30 minutes after the scheduled starting time to show visitors around the Observatory and let you at least look at the telescopes, if not through them.

If you're uncertain as to whether or not we'll be open, you can call the Observing Deck at 303-492-2020 (no earlier than 30 minutes before the scheduled starting time) before making the trip to the Observatory. You may or may not get an answer, depending upon whether a host has arrived and/or whether s/he is able to take the time to get to the telephone. Please do not call the regular Observatory number Friday afternoon asking if it will be clear or not - quite frankly, we can't predict the weather any better than you can! Your best bet will be to check the local forcast, or simply stick your head outside and look up....



We're often asked by visitors if they can mount their camera and take pictures through the telescopes. Sorry, but the answer is "no". The set-up time is lengthy, and the focus and exposure procedure is quite a bit more difficult than you might expect. This would prevent other visitors from having access to the telescope for stargazing - which is the whole point of the open house! You may, however, take pictures of and around the telescopes, but only if you do not use a flash! A flashbulb will destroy the night vision of others, and cannot be permitted - see below.

Dark Adaptation

It takes about 20 minutes or more for an individual's eyes to become dark-adapted (the pupils slowly enlarge to accept more light), but it takes only a fraction of a second to lose that night vision by glancing at a white light. Consequently, if you wish to bring a flashlight (which is not necessary), be sure it is covered with a red filter. Dim red light does not significantly affect one's night vision (and in fact, you'll notice that the Observatory at night is lit only with red lighting for this very reason).

Disabled Access

The Observing Deck is accessible to the physically disabled - an elevator is available to bypass the short flight of stairs. The nearest handicapped parking spaces are available on the east side of the CDSS (Communications Disorders and Speech Science) building in Lot 408, about 150 feet east of SBO, and there are sidewalk ramps between the parking spaces and the Observatory. However, please be aware that in most cases, depending upon pointing orientation, one needs to stand on a short ladder to reach the eyepieces of the 16- and 18-inch telescopes.


Restrooms are available on the main level of the Observatory (a half-flight of stairs down from the Observing Deck) at the north end of the hallway. One has recently been upgraded to be fully ADA compliant.


Sommers-Bausch Observatory is located in the city of Boulder, Colorado, approximately 25 miles northwest of Denver. Enter here for detailed directions

Local Astrophotography