Wednesday, October 2, 2019

My First Visit to Las Campanas!

I am a fifth year grad student at Michigan State University (MSU), and this summer, I got an amazing opportunity to run a nine night long observing run on the du Pont telescope at Las Campanas Observatory in the Vallenar region of the Atacama desert in Chile. I have had several remote observing nights through MSU on the SOAR (Southern Astrophysical Research) telescope as a grad student, but I had never been on site for observing (or even had more than one night in a row of observing). When I was asked to manage the second half of an observing run on the duPont telescope for several folks at the Carnegie Observatories, I hesitated at first. Prior to this summer, I had never been out of the US, and the prospect of flying to a remote mountain in a country where I didn’t speak much of the language was very intimidating. I definitely considered not taking this opportunity. However, I knew that this experience was too cool to pass up, and I’m so glad I did it.
The view over La Serena from the El Pino office before heading up the mountain

After about 30 hours of travel from Michigan to Las Campanas, including a bus ride, 3 flights, and two shuttles, I finally made it to the mountain just in time to meet up with Jeff Rich (from Carnegie) who would show me the ropes on the telescope for a few nights before he headed home and I took over. He also gave me a great tour of the grounds and telescopes, showed me the best spots to look out for the local wildlife, and demonstrated the “ringing rocks” out by the duPont telescope. There is something about the composition of the rocks and how they have broken that means they ring like a bell when hit just right. Since Las Campanas translates to “the bells” in English, I believe the rocks are at least part of the origin of the observatory’s name.
After a few days, I went from shadowing to running the telescope, and my nine night run began. On my first night alone, I met some wildlife companions on the road (see photo, just drive slow and they move eventually!) and I watched an amazing sunset before kicking off observations for the night. 

Burro friends on the road to du Pont!

A beautiful sunset seen from the du Pont telescope parking lot

Because winter weather is generally marginal for observing, I thought it would be unlikely that we would have good enough weather for nine nights in a row. However, we were fortunate to have only one partial night that was too cloudy to observe and a bit of time over a few nights where the wind speed was high enough that it was unsafe to open the dome. The fun part about observing for others is that I got to really see all the things that the Wide Field CCD (WFCCD) on duPont can do. I took spectra to help follow up and classify supernovae and broad band images of supernovae to help determine what was needed for follow up spectra for the All-Sky Automated Survey for Supernovae (ASAS-SN) project. Spectra are taken by passing the light through a narrow slit and spreading it out into its components (much like sunlight through a prism), and they are used to learn what elements and ions make up the object we are looking at. I also took many spectra in a row stepping one slit width across the face of a few beautiful nearby galaxies for the TYPHOON project to map the stars and gas as well as single spectra searching for tidal disruption events (when stars get close enough to a black hole that they are torn apart). The most difficult challenge of the run was mounting a custom cut slit mask to do some multi-object spectroscopy on a galaxy cluster! 

Rachel standing next to the 100 inch du Pont telescope

 On the last night, I had a few open hours of observing time, so I took some broad band  images and some spectra for two of my own galaxy clusters. Broad band images are taken using filters that block out emission at certain wavelengths, particularly those from the  atmosphere, so we can learn where different wavelengths of emission is coming from. I study the hot gas in galaxy clusters and nearby early type galaxies in the X-ray and optical wavelengths. For these two objects, I was looking in the optical wavelengths to identify the brightest, most massive galaxy in the cluster (known as the BCG) to compare to the existing X-ray data. Throughout the whole run, I had the support of the amazing telescope operators and the folks from Carnegie, and it made for a very fun and exciting observing run, though I was exhausted by the end of the run. Fortunately, the never-ending supply of espresso, tea, and delicious Chilean snacks kept me going throughout the run. While the winter nights were long and took most of my time, I did get the chance to test the gym on the mountain (it could do with a squat rack, but was still enough to keep myself on track with my powerlifting training) and enjoy dinners in the lodge. It was fun to chat with other astronomers about what we were observing and cross our fingers for clear skies.

The chefs at Las Campanas are most known for their empanadas, but they make tons of other delicious food!
This was chicken soup, stir fry, and tiramisu.

Having the opportunity to visit LCO was unforgettable and I’m so grateful for the opportunity. Getting to work on location with a telescope and balancing the needs of several different people helped me learn that I have strengths I didn’t know I had and opened my eyes to potential career paths as I near the end of my PhD. I had never realized that there are people who both manage telescopes and get to do their own research, but now I’ll be looking for those jobs as I finish my thesis work next year. In short, I am so glad that I went and would encourage other astronomers to do the same!

Foreground: The Magellan telescopes (Baade and Clay)
Background: The du Pont and Swope telescopes