A week ago this morning, the last of the Dark Energy Survey observing teams bid farewell to the Cerro Tololo Inter-American Observatory (CTIO). Our third, six-month long, season of observations is over, and we won’t return until the Fall.
In the past, an astronomer would leave the summit with a suitcase full of data tapes and hand-written logbooks. However, in this digital age, our 57 DES shifters (members of the observing teams) leave only with their memories and photographs. Some of the shifters have generously shared these with us for this special Dark Energy Detectives case log.
Their memories include the expected (sunsets, weather, cute animals, food, and the beauty of the night sky) and the unexpected (meteors, friendships, setting observing records, and girl power).
Our favorite of all was the accidental observation of Comet Lovejoy. We have featured this observation in this case file (image at left). It reminds us that before we can look out beyond our Galaxy to the far reaches of the Universe, we need to watch out for celestial objects that are much closer to home!
The memories range from short sentences to long paragraphs. We have ordered them by increasing length to help those of you with only a few minutes to spare.
The avocados at the CTIO canteen. Delicious!
Setting four out of a possible five “best seeing” records for DES one night.
The shock of seeing an accidental observation of Comet Lovejoy pop up on the display in the control room!
Seeing my first fox on the mountain!
Finding a scorpion in my shoe one morning.
Spending Christmas night 2014 in the Blanco control room.
My first glimpse of a momma viscacha and her baby watching the sunset from the edge of the cliff. Adorable!
The DES atmospheric monitoring camera is amazing. I remember thinking “I wish I’d built this!” the first time I saw it.
The seemingly never ending variety of cookies that are supplied with the packed night lunch: it is a delicious mystery every time!
Getting an extra night of observing for DES because we finished the Liquid Nitrogen pump replacement a day early.
Some of my favorite things about observing at CTIO include: watching the sunsets,; getting to know the other observers; thermoses full of hot tea; galletas de coco; and being alone with my thoughts.
Looking up at the stars, with the silence only broken by the movement of the telescope dome. I’ll never look at the sky on a cloudy day the same way again, knowing what’s right there, just behind them.
I feel lucky to have become good friends with many of the CTIO staff in La Serena and on the mountain: the taxi driver, the cooks, the telescope operators…. Every time I go back, there are so many high-fives and smiles.
I’ve visited CTIO many times, but every time I return I feel like I am entering a new world: The dryness of the air, the brightness of the sun, the darkness of the night. But once I’ve caught my first glimpse of Milky Way plastered across the sky like a snow globe, at feel at peace, I feel like I’m home.
After dinner one evening, we headed up toward the summit to begin observing. It was clear when we set out, but by the time we got there, clouds had risen rapidly from the valley below. The clouds enveloped the summit and blocked out the sunset. We couldn’t even see the telescope dome 50 feet in front of us.
We often have all-women observing crews observing for DES, but during my recent visit, there were all-women crews at all Tololo telescopes at once. Looks like the “old boys club” is truly becoming a thing of the past!
The very first time that I stepped out of the observatory to look at the night sky, I saw the bright flash of a meteor breaking up – it was huge and actually made a crackling sound as the embers fell from the sky. I thought the Third World War had started. My immediate reaction was to run back to the dome to protect the telescope!
One of the pleasures of being at the mountain is meeting other astronomers from around the world. I ate several times with a group of Koreans that had been working on a big new camera for several weeks. Some nights I wouldn’t see them at dinner, and I wondered why. When they invited me to have dinner with them at their guest house, I found out why: they had brought enough food from Korea to last for months!
For two days in a row, before our observing shift began, tried without success to catch sight of Iridium communication satellites (their positions can be found from this webpage www.heavens-above.com). One the third night, after some moments of silent expectation, we saw a spot brighter than Venus come into the twilight sky for a few seconds in the direction we were expecting it to be. I remember that I jumped in the air and yelled ‘wooho!’. I was so excited to know the prediction was true. It made me think of historical examples, such as the prediction of the existence and position of Neptune using only mathematics. I can’t imagine the excitement astronomers felt when they actually saw the planet in the place he predicted!
What stays with me the most, when I leave the beautiful mountain, is the memory of the starry blanket that slowly envelops me when I step outside the dome on a moonless night. At first, the blackness is nearly absolute. But as my eyes adapt to the darkness, the brilliant and strange stars of the southern sky come into view with an intensity unmatched at home. High on that remote mountaintop, with the Milky Way arching overhead from horizon to horizon and the Southern Cross shining brightly, the human world is reduced to a dim orange glow off in the distance. In this private moment, I forget the official role that brought me there—“Observing Shift Run Manager”—and take on the only role that seems appropriate for one small human being living his brief moment in this vast cosmos: “awestruck participant.”
So, there you have it folks. Another DES season is over and our collaboration must now turn its attention from observations to analysis. Of course we love the analysis part (that when the fun science gets done), but I suspect most of our Season 2 DES shifters still wish they could click their heels together and be instantly transported back at our beloved mountain (and that would be especially nice, since it usually takes at least 24 hours to get there!)
We’d like to end with a conversation that one the final shifters of the season had with one of the CTIO telescope operating engineers: the tel-ops staff stay with us observers night after night throughout the year (even on Christmas Day), to make sure everything runs smoothly:
Q: So, do you work with DES folks a lot?
A: Yes, I work with DES people all the time. Every week there is a new team. I remember everyone. They are all a little different. The computer lady, the one with the hat, she is the best.
Q: Did you know it is our last night until September?
A: The last night?! No… Seriously? But I am sure you guys will be back. You always come back
Quotes from the following detectives who were on shift:
Jim Annis, Aurelio Rosell, Ross Cawthon, Chihway Chang, Alex Drlica-Wagner, David Gerdes, Ravi Gupta, Manuel Hernandez, Steve Kent, Christina Krawiec, Bob Nichol, Brian Nord, Andres Plazas, Kathy Romer, Marcelle Soares-Santos, Douglas Tucker, Yuanyuan Zhang
Pictures from the following detectives:
Jim Annis, Ross Cawthon, Chihway Chang, Kathleen Grabowski, Ravi Gupta, Christina Krawiec, Jennifer Marshall, Andres Plazas, Kathy Romer, Marcelle Soares-Santos, Douglas Tucker
Post written by Det. Kathy Romer (U. Sussex)
Loveyjoy image credit: Det.’s Marty Murphy, Nikolay Kuropatkin, Huan Lin, Brian Yanny (Fermilab)