Reservations for the free annual open house at Allegheny Observatory will be taken by phone beginning at 9 a.m. today.
Open house at the historic observatory in the city's Riverview Park will be held from 7 to 10 p.m. Friday, Oct. 11. Groups will be permitted to enter the building every half hour.
During open house, visitors see and look though the 30-inch Thaw Refractor, the observatory's primary research instrument. The 13-inch Fitz-Clark also will show off the night sky.
Members of the Amateur Astronomers Association of Pittsburgh will set up portable telescopes on the lawn for public viewing.
Participants will enter the observatory every half-hour and will begin the self-guided tour with an introductory talk in the lecture hall.
Space is limited and registration is a must. Call 412-321-2400.