Wednesday, June 5, 2013

Two Years at Lick Observatory

When I found out that guest blogger, Sethanne Howard, had worked at Lick Observatory in the 1960s, I immediately asked her if she would write about the experience. Such a story not only plays to my love of the history of astronomy, but also to my other love of women in history. I had been thinking that we know a lot about a few famous women astronomers, but as a community, we know very little about the careers of others. Sethanne reminds me that this story represents only two years of her career, but having read, Eye on the Sky: Lick Observatory's First Century, and James E. Keeler: Pioneer American Astrophysicist, this story was impossible to resist! -- Joan Schmelz

I spent two years at Lick Observatory – Let me share with you what Lick was like way back when. First a little geography. Lick Observatory sits atop Mount Hamilton outside San Jose, California. Mt. Hamilton is part of the Diablo range of mountains. There is a 26 mile crooked road that winds its way through the mountains to reach the summit at 4200 feet. That road is – to put it bluntly – a challenge to drive. It is full of sharp u-turns on a road about one and a half cars wide. I forget what the shortest time from ground to summit is – but it was around 25 minutes. The road is so curvy because when the Observatory was built and equipment brought from the city below to the summit, it was brought by mule train. The mules could handle only so much incline. The road follows the old mule train road.

It has a history filled with legend and astronomy. Founded in 1888 and paid for by the James Lick estate which pushed for the largest telescope in the world. That was true for a time until the Yerkes 40" refractor came online around 1897. Lick had a 36" refractor (James Lick is buried in the pier). Lick was the wealthiest man in California and his donation to the telescope in today’s dollars ($1.2 billion) is still more than modern private investments. The world’s astronomers found their way to Lick to work under the dark skies, well above the inversion layer. One could see half dome in Yosemite off in the far distance across the valley. The skies are still dark but the inversion layer has risen. When I was there the inversion layer was just beginning to creep over the mountain top.

Lick was an independent entity under the auspices of the Regents of the University of California. The staff lived on the mountain. Most of the people there worked in some way associated with astronomy. There was a one room schoolhouse, a post office, a machine shop, homes for the married staff, a dorm for visitors and single staff, and, of course the telescopes. The 120" had opened just before I arrived. Access to it was extremely limited. Very few people had keys.

I came to Lick in the summer of 1965. In those days, observatories hired recent college graduates as “astronomical assistants” (these are not night assistants). Each assistant was assigned to a staff astronomer to learn the trade and skills of astronomy. We lived in the dorm and ate in the dorm cafeteria. And once a week we would gather around the one television in the dorm to watch Mission Impossible. (We also sat on the parapet around the Main Building and rolled old tires down the mountain, but you did not hear that from me.) The tenure of an assistant was two years max. Then the person was expected to enter graduate school. I was the next to last assistant hired at Lick. There are no more astronomical assistants.

There were several staff astronomers living on the mountain when I arrived. Dr. Whitford was the Director. I was assigned to Merle Walker. He had been awarded the Trumpler Prize for his work in the ages of open cluster. Others I can remember are Joe Wampler (I did get to use the Wampler scanner), George Herbig, Tom Kinman, and Stan Vasilevskis. There were several graduate students from Berkeley and UCLA coming and going while working on their PhDs. We had telescope engineers, a night assistant for the 120", and other specialists.

There was one computer – an IBM 1620. Very few people were allowed to touch it. Because I had had a course in Fortran, I was one of the lucky few.

Merle taught me how to observe, handle photometric photometry, spectral analysis, and lab skills for handling the Lallemand Tube – an electronic camera that was extremely difficult to use. Merle was one of the few in the US to use this image tube. When Merle’s post doc left I was picked to help with it. It took 3 days to set up, one day to use, and 3 days to break down before the plates could be withdrawn and developed – a week before you knew if you had usable spectra. And even then it was a 50/50 chance that the plates would be good (or damaged in their manufacture). It was used with the 120". I can remember sitting in the Coudé Feed room in absolute darkness waiting to see if the camera would spark before use. No sparks were good. It was connected properly, and we could observe. While observing the camera had to be kept at the temperature of liquid air. So for the entire observing run we would trade off filling the Dewar with liquid air every 30 minutes, 24 hours a day.

I managed to do UBV photometry of every bright star in the Orion Nebula (pounding dry ice into shards which would cool the photometer). Photometry data were reduced by hand. Taken on a Brown Chart Recorder, the marks on the paper strip were measured with a glass engraved magnitude ruler. I reduced data for inverted P Cygni stars, and computed the rotational temperature of Jupiter during my time at Lick. Oh yes, I attempted to compute (with the IBM 1620) the masses of Seyfert galaxies using spectra taken with the Lallemand Tube. I had such trouble with the galaxy cores. They kept putting spikes in my data – of course the mass models of the day did not quite know how to treat the bright Seyfert cores, so I kept getting unusually massive galaxies.

The students and assistants had offices in the Main Building – it connected the 12" refractor to the 36" refractor. Unfortunately today the 36" is closed to observing. Earthquake damage finally was too much to ignore. When I was there, though, we enjoyed using the 36". Stan was finishing his second epoch scan of the sky. The glass plates he used were 17 inches on one side, and the camera weighed 200 pounds. That meant when the camera was removed, the telescope had to be hooked to the floor to prevent it from getting out of balance. Of course there was the person who forgot to do this. He panicked and grabbed the telescope ring as it rose up. He did not weigh 200 pounds, so the telescope kept rising. Then he panicked again and let go, falling to the floor. The lens end crashed to the floor, sending rumbles through the building. Not what one wants to hear. The astronomers in the building raced onto the observing floor, leaped over the body on the floor and ran to the lens to see if it was cracked. One has priorities after all. The young man had broken a collarbone but was otherwise all right. The lens was indeed stressed. The other young men enjoyed reversing the pier of the telescope. One could drive it safely from atop the pier, or … one could hang onto the ring and start to run, leaving the ground, hoping to come down on the other side to meet the floor with no impact. I never had the courage to try that technique.

For me, the most beautiful pictures were taken with the Crossley. It had a Newtonian mount which meant the observer had to crawl on hands and knees on a board, flashlight in mouth, out to the eyepiece, center the telescope, and back up to the stairs. Despite the danger only two people had been hurt observing. It was worth the risk, the photos were awesome. I still have framed prints.

I can still remember the end of one observing run. It had been a beautiful night. I walked down the path from the telescope to the dorm in that special time before sunrise to see Comet Ikeya-Seki stretched across the sky. This is why we are astronomers.

Politics did play a part. Lick was under the Regents of the University System. Both Berkeley and UCLA wanted to bring the place under their control. The result of the negotiations put Lick under the control of UCSC. So we moved to Santa Cruz in the summer of 1966. None of us wanted to go. To make it worse we lost our wonderful librarian on Rt. 17 in a car accident. Stan hand carried his second epoch plates down the mountain.

Apparently we were the first research scientists to appear on the young campus. I can remember sitting in my office with an open window (those long, tall, narrow windows). Once, some students went by outside whispering “look in there – that is what the desk of a scientist looks like. It is covered with papers.” I guess their professors had tidy desks.

It is a time I cherish in my memory.