Thursday, May 24, 2018

The weather is good, but....

From left: Me (Juliette), Johanna Teske, Sharon Wang, and
Erin May in the Clay telescope dome. Erin and I are
observing on Baade this week, and Sharon and Johanna
are observing on Clay.
Hi! My name is Juliette Becker, and I'm a graduate student at the University of Michigan. This week is my first Magellan run, using IMACS to look at a white dwarf with a disintegrating planet and also at some transiting planets. I am observing alongside Erin May (a fellow UMich graduate student and IMACS pro!), and we have a four-day run this week. Johanna Teske and Sharon Wang are observing on Clay this week, so it's ladies' week at Magellan!

Erin has in the past had terrible luck with weather at Magellan; it seems to be cloudy or raining every time she comes to observe (the running joke is that she's "cursed"). We've been checking the forecast for the last few weeks, getting nervous when it looked like there might be clouds and getting happy when the forecast became more favorable. When we arrived here Sunday evening, the weather was pretty good, with just some scattered clouds. The forecast looked favorable!

Monday night, the weather got even better. We were able to get on sky on-time and observe both of our targets for the night! There were some scattered clouds, but it wasn't too bad. We reduced some preliminary data, and things were looking pretty good.
Pretty good weather, with only scattered clouds!
Come Tuesday, we were excited to get more data on our targets: it appeared that the "curse" was broken, because the weather was great! We did our calibrations Tuesday afternoon, headed back for dinner, and returned to the telescope before sunset.

When we arrived at the telescope, several of the local Magellan engineers and instrument specialists were in the control room, looking concerned. The guiding wasn't working, and they quickly determined (as Erin and I looked on in horror) that the reason for this was liquid on the camera. My first thought was "Liquid? How did that happen? It hasn't even been raining!", but things quickly got worse...

The engineers determined that a hose had a nick in it, resulting in glycol spilling everywhere. And it wasn't just a spill - it had spewed all over the instrument and the local area, resulting in a GIANT MESS:
Video of the aftermath of the spill, courtesy of Gabriel Prieto.
As the engineers worked hard to fix the spill and get the instrument functioning again, things were not looking good. It seemed like IMACS would not be functioning again for at least two nights, but one of the engineers mentioned that they could unplug IMACS and plug in another instrument. Erin and I scrambled to get backup targets that we could observe using another Baade instrument, so as not to waste valuable Magellan observing time!

As 11pm approached and the engineers continued to work, we had come up with a list of backup targets for FIRE, calibrators, and an observing plan. Even if IMACS wasn't working the next night, we would be able to observe on FIRE. At this point, I was totally convinced of the existence of Erin's observing "curse." Clearly, the curse hadn't been able to control the weather this time, so it had decided to take another approach...

But just as we almost reached the point at which we would not be able to observe our transit, the Magellan crew came back from the dome with good news: they had a temporary fix for IMACS, and we could get on sky after all! We finally got on sky ten minutes before the transit we were observing, thanks to the herculean efforts of the telescope operators, instrument specialists and engineers on site. The guiding system was out of commission, so our telescope operator Alberto had to focus the telescope manually all night. In the end, though, we were able to get data for our second target of the night.

The lesson I've taken away from this trip is that it takes more than good weather to have a successful observing run: you also need a talented crew of telescope operators, instrument specialists and engineers ready to save the day if something goes wrong!

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