The following is the normal schedule for evening use of Chamberlin Observatory:

SUNDAYS -- Director's night/DU classes
MONDAYS -- DU astronomy classes
TUESDAYS -- DAS Public Night
WEDNESDAYS -- DU astronomy classes
THURSDAYS -- DAS Public Night
FRIDAYS -- [first quarter moon] Monthly DU alumni night FRIDAYS -- [full moon] Monthly DAS 'after-meeting'
SATURDAYS -- [first quarter moon] DU-DAS Open House event

Link to latest attendance figures

Click here to reserve upcoming, available Tues or Thurs Public Nights
Note for school groups**: The best approach would be to reserve an upcoming Tues or Thurs public night: search on keywords Denver Astro Public Night Reservations. Ideally, groups should be smaller than 2 dozen to avoid long waits for a look in the eyepiece, and probably best if the students are at least ten years old, especially as it doesn't get dark til after 9pm during spring and summer [earlier during fall/winter/MST]. Our helpers offer a slide show in case of clouds, but normally don't start that til after 8pm during daylight saving time part of the year [730pm MST part of the year].

OTHER Special events may be requested, especially for open Fri-Sat evenings AT LEAST TWO WEEKS IN ADVANCE by emailing the Director ( calling 303-871-5172. . Observatory rental starts at $1,000 per night, plus extras**. Research proposals for telescope time are welcome anytime.

The observatory is not well designed for social events**, so we limit events to those with an astronomical focus. Alcohol is not permitted on site.

Daytime access to the observatory can be arranged**, depending on the proposed use [see notes, below]. General info or comments: 303-871-5172.

Thank you for cooperating on these scheduling policies that are intended to help avoid double booking, unsafe conditions, and ensure longevity of the facility and telescope. 

**More notes for external groups, added 10-30-2017: The historic 1890 observatory building was not designed to be a public facility, so limitations exist - including no ADA accommodations, only one rest room, and fire code limits on group sizes to no more than 24 including chaperones. As such, we do not host parties, weddings, photo-shoots etc.  To improve the odds for a successful visit by your group, please answer the following:  (1) what is your goal for visiting DU's historic Chamberlin Observatory, and why this cannot be met during one of our regular evening programs?  (2) what is your group size, including chaperones?  what typical ages are involved?  (3) we normally require at least 2 weeks notice prior to a group visit, to insure availability of space and helpers - what is the span of dates you are considering?  (4) we have no budget for extra programs beyond DAS public nights and DU classes -- what reasonable amount would you consider in terms of paying DU for the privilege of access outside of those normal hours?  Please email your reply to Prof. Stencel at robert.stencel AT or phone 303-871-5172.

More policy detail, 5/5/03:
Because of a recent occurance, it is time to spell out the assumptions
once more: Chamberlin Observatory scheduling procedures exist to prevent
double booking and chaos.

Keyholding is a privilege, not a right. We extend keyholding privileges
to DAS members who take lead roles in providing the DAS Public Night and
Open House functions -- specifically for those purposes.

I value our relationship with the DAS because it provides 8 to 10 monthly
astronomy events for the public that might not otherwise exist.  Note, DAS
is the only non-DU group to have this level of access.

In return, we ask the DAS to observe a set of safety and training
procedures, to carry liability insurance, to ensure the
continuation of the relationship and future of the observatory
facility.  Each keyholder represents DAS and is therefore covered by the
DAS liability insurance.

Whereas DAS volunteers deserve perks, if DAS keyholders schedule private
groups outside of the regular DAS program, DU still views these as DAS
functions subject to the same rules and liabilities, with the E-BOARD/DAS
ULTIMATELY RESPONSIBLE AND LIABLE in the event of injury claims or damage.

Henceforth, failure to SCHEDULE special events other than regular DAS
Public Nights, monthly Friday after-meeting or Saturday Open House, may
result in loss of privileges. THESE REQUESTS MUST BE MADE *AT LEAST TWO
Observatory. There areseveral Friday and Saturday evenings open each month 
for such purposes.

Your cooperation is appreciated and will help avoid double booking
problems.  I ask for notice so as to
check calendars, etc.  After hours, please observe decorum [limit the
noise for neighbors] and be aware of the 11 pm park curfew - police can
ask you to leave IF you are wandering around outside the building.  To
minimize intrusion by "park people" please keep the doors locked.  

Prof. Robert Stencel, Director of Chamberlin Observatory
updated 3/9/2005