Telescopes I've Used - Lick Observatory

Lick Observatory (University of California), Mount Hamilton, California

Moonset over San Jose from Mt. HamiltonLick Observatory, long the primary astronomical facility for the entire University of California system, is where I did my graduate training, and much of my dissertation research. Given its modest altitude of only about 4200 feet, the mountaintop views are unusually spectacular, including San Francisco Bay as far north as Mt. Tamalpais, Monterey Bay, and on a clear day looking across the Central Valley, the Sierra Nevada from near Mt. Whitney to well north of Yosemite (that's Half Dome in the picture below). Of course, I was most taken with the night-time views, especially when San Jose was covered with fog. In the night-time view of the main building with the 36-inch dome, that illumination isn't moonlight - it's named after a newspaper, San Jose Mercury (the picture having been taken in about 1980, just as the switch to low-pressure sodium lighting was beginning). The sunset picture with crescent Moon is pretty spectacular, but the city lights in foreground can be alarming if you're trying to look deep into the Universe.





Lick Observatory Lick dome by night Yosemite from Mt. Hamilton

The overall view includes the main building with the original 36" refractor and 1m Nickel reflector at far right, the 3m dome in the center, and (in the distance) the Crossley dome to its left. The former home of the 60-cm Boller and Chivens reflector (now occupied by the Katzman Automatic Imaging Telescope) is at extreme left, much closer than the others in this view from the east. The Carnegie astrograph is hidden from this vantage point.

There is a USGS aerial image available from Terraserver. The coordinate assignment is a bit off, so it takes some fishing to find this for the first time. Possibly more useful is the location on a satellite image from Google maps. Many of the same features are seen in the following view from the window of an American Airlines Boeing 727 (the relevance being that 727s didn't have the engine exhaust blurring the view behind each wing at low altitude). This is a view looking to the northwest in early morning, including one of the frequent fogs that settle below the summit of Mt. Hamilton. The domes of the original 36" refractor (left, in the main building) and 120" Shane reflector (right) are most prominent, with the Crossley telescope on the ridge to the lower left of the main building and the double astrograph to the immediate left of the Shane telescope.

Aerial view of Lick Observatory

Mt. Hamilton is a popular tourist destinction, especially for sunset watching. I couldn't resist this slightly impressionistic picture of some viewers and their transportation in front of the Lick main building one evening in the summer of 1980:


36-inch (0.9m) Crossley telescope

36-inch Crossley telescope Crossley dome
Telescopes sure can last. The Crossley was moved to Mount Hamilton from England before 1895, and its "new" mounting dates to 1919. Still, I can't recall any observing in which I took greater pleasure than direct photography at the Crossley. The camera is at the f/5 prime focus with a guiding eyepiece at the top of the tube, fed by a prism. You're right out there at the top of the telescope on a platform in the middle of the open dome slit, with half the sky (and all too frequently, all of San Francisco Bay) spread out before you. Of course, in winter when it gets below freezing even near San Jose, I can't recall any more miserable observing either.

Intrepid observer using the Crossley prime-focus scanner One major program I did at the Crossley was photographic monitoring of variations in the lensed double QSO 0957+561 over the couple of years after its discovery - which led to my first solo paper in the Astrophysical Journal, fittingly enough in the April 1, 1982 issue. I also did lots of galaxy photography, for such purposes as astrometry to register optical and radio structures (which was a bigger deal before the Digitized Sky Survey became available, and each field had to be individually measured and a separate plate solution computed for every time the plate went on and off the measuring machine). The early photographic archive (going back to 1895) allowed an unusual project, comparing pictures of QSOs seen close to nearby galaxies with much older pictures to look for the long-term variations in QSO brightness that some gravitational lensing models would predict. Here are a few blue-light Crossley photographs of galaxies, vintage 1980-1982, plus an art shot of M17 in red light to fill the time as the summer Milky Way interrupted the galaxy list. Exposures for the galaxies were 20-30 minutes on 103a-O plates, while M17 was an hour on 103a-F red-sensitive emulsion.








Crossley photo of double quasar Crossley photo of galaxy NGC 4192 Crossley photo of galaxy Arp 220 Crossley photo of galaxy NGC 4800 Crossley photo of Omega Nebula, M17
Double quasar NGC 4192 Arp 220 NGC 4800 M17

Crossley near-IR spectrum of NGC 1068 For a few special purposes, the original Wampler single-channel spectrum scanner was around, which was one of the few instruments at the time which could measure spectra just longward of one micron. As an example, here are some spectral features of NGC 1068 in this region, including reddening-sensitive [S II] emission lines.





40-inch (1.0m) Anna Nickel telescope

Control room of 1-m Nickel telescope at work Moon over 1-m Nickel telescope I arrived at UCSC just in time to follow the construction of the Nickel telescope, from being part of a grad course which made some minor changes to the design (if you've been there, the elbows in the northern yoke supports were our contribution), through preliminary mechanical assembly in the shops on campus, to pointing tests, and jumped right in to be the first full-fledged Ph.D. project done on the telescope. This telescope was based on an f/5 primary mirror originally planned as a replacement for the Crossley's mirror, but ended up in its own instrument, completely built in the Lick shops at UCSC and pushed financially upon a bequest by Anna Nickel. In all, I measured something like 700 spectra of about 200 galaxies, plus a library of giant and main-sequence stars for spectral synthesis. The 1-m telescope was installed in the dome formerly occupied by the first permanent telescope at Lick, the original 12-inch Clark refractor, at the north end of the same building best known for the 36-inch refractor. By the time I left UCSC in 1982, I had used about 10% of the dark time ever allocated on this telescope (something I'm unlikely ever to manage again on an instrument that I didn't pay for). I did make a point of patting the mirror cell goodbye that final morning. This plot compares the spectrum of galactic nucleus with a synthetic spectrum composed of nearby stellar a examples, and the difference shows weak emission lines that are nearly lost in the fine structure of the ordinary starlight spectrum.

Dome of Lick 40-inch reflector Lick 40-inch assembled in machine shop NGC 5866 seen on 40-inch acquisition TV

120-inch (3m) Shane telescope

Shane 3-meter telescope Dome of Shane telescope in snow This telescope, starting from a glass blank used in testing the 200" Palomar primary mirror, kept the University of California competitive in optical and infrared astronomy with their neighbors to the south up until the design of what became the Keck telescopes. As far as I know, this is the smallest instrument in which observers routinely worked in a prime-focus cage. Okay, so the official UC policy at the time was that no grad students could be listed on the 120" schedule as the observers. I did manage a half-night in the prime focus cage during the first checkout of a CCD spectrograph. The [O III] emission lines really are an unearthly green, as I found when finishing the night with a calibration spectrum of NGC 7027 and telling the operator that I wasn't quite ready to move the telescope until Nebula Appreciation class was over. That very dim blob through the acquisition eyepiece really was Cygnus A, as we could tell when the spectrum came in. Ski Antonucci and I did end up with a night of our very own - which was snowed in, as photographically documented here.

Dome of Shane telescope in more suitable weather Eager grad student in prime-focus cage of Shane telescope

Carnegie 0.5-m (20-inch) twin astrograph
Carnegie astrograph dome Carnegie double astrograph

The Carnegie double astrograph was built for a single dedicated project - a long-term astrometric study of vast numbers of stars, using distant, faint galaxies as an inertial reference frame. This would yield newly accurate information on galactic rotation and stellar populations. The two objective lenses are best corrected for blue and yellow light, so that both wavelengths can be observed simultaneously. The first epoch of the survey began about 1947, with the second epoch of identical exposures completed in the 1980s. The blue lens has an image structure which grows rapidly to brighter magnitudes, which allows quite accurate photometry, while the yellow lens gives very sharp Schmidt-like star images. The survey observations used a wire grating over each objective, giving a short set of diffracted spectral images to the north and south of bright stars. This means that the positions of bright stars could be measured precisely by averaging the diffracted images, instead of finding the center of a huge overexposed blob. Since the survey exposures were long - two hours - tracking was important, so the astrometrists at Lick would re-adjust the polar axis to point at the appropriate refracted pole for each declination band being observed. Furthermore, they also had to adjust its pointing after each major earthquake in the area, to compensate for the slight rotation of Mt. Hamilton as the two sides of the San Andreas fault complex slide past each other.

As part of the graduate course on observing techniques, we each did practice plates with the astrograph. These included pictures of M31 (1 hour on 103a-O emulsion, blue astrograph - stick with the classics, we thought), and later a field around the double QSO 0957+561 including the edge-on spiral NGC 3079 (1 hour on 103a-G with the yellow lens through cirrus), showing the multiple images produced by the objective gratings. The double quasar is near the upper right corner of this excerpt, with NGC 3079 and its companion Markarian 131 near the bottom. These were scanned from contact prints made from the original 8x10" plates. Normal survey data were taken on still larger-format plates, 20 inches square and 1/4 inch thick. Only three astrometrists were allowed to handle these.

Blue-light photo of M31 Yellow-light photo of NGC 3079 and double quasar


Telescope Collection

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