40.384 N, 74.659 W
(40°23' 02" N, 74°39' 32" W)
UTC-5 EST, UTC-4 EDT
The department of Astrophysical Sciences at Princeton University holds monthly informal open houses for the purpose of observing the night sky. Weather permitting, we can usually look at planets, nebulae, open clusters, globular clusters, and galaxies through a 12” Schmidt-Cassegrain telescope. We (being the students and postdoctoral fellows in the department) are also quite happy to answer any astronomy-related questions you might have.
It is an open house, so come anytime during the above interval and stay as long as you like until closing. We will update the above calendar in the afternoon the day of scheduled public observing to indicate whether it is on or canceled due to weather, but there is no guarantee, of course, that the weather will not change between then and the start of the session, so please check the "Status" (above) on this website before you set off. For a last-minute check please look outside before leaving your house; if you can’t see any stars, neither can we!
IMPORTANT: Peyton Hall will be being renovated this spring and summer and there will be no public access to the building, so there will be no sessions February-September. We may be able to organize a few special sessions elsewhere on campus during this period, so check this page occasionally.
WHERE: Peyton Hall, Ivy Lane, Princeton University. From the street entrance, come in and turn right down the hall. Find the stairs on your left just before the end of the hall and go upstairs to the telescope room.
WHEN: Open houses this year will *usually* be on the second or third Wednesday (sometimes Tuesday) of each month (in the event of cloudy skies, bumped *usually* to a week later), at 8:00 PM (9:00 PM when daylight saving time is effective, 9:30 in May). Sometimes these days/times will be moved because of competing campus events or the availability of people to run the open houses, or particularly favorable or unfavorable phases of the moon, so watch this website. We will try to give as much advance notice of changes as possible.
For more information, contact Prof. Jim Gunn
Note: We usually decide whether the weather will be good enough to hold our observing session by about 3:00 PM on the day in question. Please check this site after that time to make sure that we’re going ahead, and please check it again immediately before you come! Sometimes we make mistakes, and we cancel when the weather is clear, or are forced to cancel at the last moment because of unexpectedly bad weather. Apologies in advance for all such mistakes. If you’re really interested, check the Clear Sky Chart tab (the same astronomy weather info we use to make such determinations).