New Displays at the Observatory

Back in December I posted about The Known Universe, a new video from the American Museum of Natural History. It is part of a series of videos produced as a part of their Science Bulletins which are now on display in HD on a 50-inch monitor in the Palomar Observatory visitor center.

In case you have forgotten what The Known Universe video, here it is:

The other item that is newly on display is a Warren Sidereal Time Standard.


This is a Warren Sidereal Time Standard. It is an electromechanical device also known as a vibrating-string or -wire oscillator. It was used at the Palomar Observatory to help astronomers keep track of Sidereal Time, which is used to determine the locations of stars in the sky.

The first one was purchased and applied to the 18-inch Schmidt telescope in 1938. Shortly thereafter three more similar Warren standards were purchased and applied to the drive system of the 200—inch Hale Telescope.

The oscillating wire units were used to generate the proper sidereal frequency to drive the telescope tracking motors so as to keep up with Earth’s rotation, thereby keeping astronomical objects centered in the telescope’s field of view.

Electronic oscillators replaced the time standards in the early 1960's.