Professor Emeritus George Wallerstein is celebrating the 60th anniversary of his first telescope observing run with an Echelle spectrograph observing session on the Apache Point Observatory (APO) 3.5-meter telescope. His first observing was done on the 1.5-meter telescope at Mount Wilson Observatory in January 1956, when he was a graduate student at Caltech. George notes the vast differences between observing “back then” and now.
“The Echelle spectrograph provides vastly better resolution for stellar spectra than what was available in the 1950s,” says George.
This is good news for George’s studies of chemical abundances in stars. Higher resolution means more clarity for identifying and measuring the signatures of various atoms and molecules. Another difference is that there were no computers involved in observing during the 1950s. Spectra of stars were recorded on small glass photographic plates which had non-linear responses and limited dynamic ranges. Today electronic cameras are able to record the stellar spectra over very large ranges of brightnesses and transmit the data to computers for analysis.
George’s first observing session featured standing outside in the dome in the chilly February night, whereas today he is able to sit in his warm office in Seattle, control the APO telescope in New Mexico remotely and transmit the data back to UW over the internet.