Monday, August 24, 2015

A radio astronomer goes to Mars... or, Las Campanas Observatories


Coming up the mountain and passing the sign to La Silla seems a bit like traversing to a different planet, so foreign is the landscape around Las Campanas Observatory in the high desert of Chile. Barely do we have enough time to put our suitcases in our rooms before we rush to dinner, which is renowned as some of the best Observatory food around. They did not lie with this boast, the dinner is braised pork with potatoes, beets, and fresh avocado. I’d say this is a new experience for this radio astronomer, but in truth, the food at Owens Valley Radio Observatory is also exceptional. I find Ramesh, the preceding observer to my shift to make arrangements to shadow him. He’s obliging, and so Diane (the undergraduate who is accompanying me on this virgin observing run) and I follow him up the mountain. Sadly, the sky has clouds that night, but we see how to take flats, take calibration spectra, and set up our observations. We thank him and head down early, aware that 1 day from now there will be no heading down early.

The next day, I am nervous. At lunch I plot over and over in my head how the observing schedule needs to be run. What have I missed? Wait, those are empanadas. Many people have told me about the empanadas. And they live up to their expectations. I ask for two for my night lunch. One to savor tonight, and one to savor tomorrow. Diane and I arrive at the telescope just before the sun sets. I run a practice arc lamp observation, and decide to do flats in the morning. Wise move? Depends on if my prediction that my California jet lag is actually beneficial. 7am feeling like 3am seems like it would work to my benefit in terms of night time fatigue.

It becomes clear that my lessons the previous day are not the complete set of instructions I need to run the telescope, but we start. A near-IR expert on Skype with me. Then the earth under our feet starts shaking - the telescope operator knows before we do from the jiggling in the pointing of the telescope. I head toward the heavy desk in case I need to jump under it - yes, it was that big. Magnitude 6.0. Biggest earthquake this Californian has been in, and the Chileans eat 6.0s for breakfast. That is when the internet goes out, having been taken out by the earthquake. So much for my near-IR expert on Skype. No crutches for me - time to dive headfirst into the deep end.

Post-earthquake is also when the GUIs start misbehaving. At first, I think this is due to my own inexperience. The instrument scientist is called up, he comes, and it becomes clear that it is not my ignorance, but likely a cable that got jiggled in congress with the mountain. Instrument scientist and observer go and check it out, “turn it off then back on again,” and we start anew, this time I have an expert making sure that I am running things properly (word to the wise: go up in the afternoon before your run. People might not tell you to, but I am. Seriously. Do that. Don’t be like me.) Things start running smoothly, and we get a rhythm. Diane, having weathered her first (and second!) earthquake runs things like a champ, though we release her from observing a little early since her cough seems to be getting worse, and sleep is the best cure for a cold.

As I write this, it is 4:47am. A half hour ago the moon set and we got to sneak outside during a 15min integration to stare at the stars. I saw the Magellanic clouds, as well as a meteor or two. Dark sites are pretty spectacular things. We are observing the last source of my night right now, working our way to the daylight, when I will observe some twilight flats and then head down the mountain, ready to observe first thing tomorrow evening. The moon is getting fuller, but I am no longer a rookie, having scaled the learning curve without internet and with the earth shaking beneath my feet.

Friday, August 7, 2015

Calling the Night

This is my first post on this blog, and it's a bit of a shame because tonight will not be a good night for astronomy from Las Campanas.  Exhibit A, the sunset this evening:


Last night was my first night "observing" on this run. I am the PI for three nights on Baade, hoping to find some unique high-redshift galaxies to study. I put "observing" in quotes because in reality we did not open the dome. There was a brief moment of hope. The clouds looked like they were parting! But then the wind picked up. (If the wind speed is higher than 35 miles per hour, we can't open the dome because the wind could damage the telescope.) So the telescope remained shuttered and no data was collected. Well, unless you count this lovely photo of the Belles of Campanas standing on the Nasmyth platform of the Baade Telescope. 

From the left: myself, Johanna, Angelica, and Cindy

Since there is no observing going on again tonight, I thought I'd write a post about Calling the Night... This is one of the most agonizing decisions a PI at the telescope must make. At one point during a terribly hopeless bought of bad weather you say to yourself and those with you at the telescope: "Ok, we are done. I call the night. We can all go to sleep." For most of us, we stay up all night hoping and hoping that the skies will clear, that the wind will die down, or that the humidity will drop. Observers all care very deeply for the telescopes they use, and so we remain patient and understanding about the fact that the telescope remains closed - but many of us still hold out hope. You see, we plan - sometimes for weeks - for a few nights on the telescope. We make target lists, calculate optimal observing strategies and exposure times. But in the end, Nature decides. 

Last night, I called it at 5AM. The wind was above 35 mph, and one must wait for the wind to stay below that mark for a full 30 minutes before the telescope can be opened. Twilight begins around 6AM, and while I can observe for a while after twilight begins, obtaining less than an hour of data is unfortunately not very useful for my current project. But trust me, it's an agonizing decision. Last night, I made the right call. There was no way we could have opened. 

Sadly, it's a decision I expect to make again tonight. The weather does not look good. 
We are currently suffering from an extreme winter storm that is expected to last well past the end of my run and drop a tremendous amount of snow in the Andes south of here. Right now, as you can see we have 50 mph winds. You can feel the wind shake the telescope building from time to time. It's kind of gloomy. 

I've called nights before. Last year, I was at Magellan for the 4th of July. It snowed. 



When there is snow on the dome, you call the night. Even if it stops snowing, the snow on the dome can melt and drip onto the telescope - or blow off the dome and onto the telescope. That's an easier decision - there is no chance for the night once there is snow on the dome. 

I'm here until Tuesday - I'm hoping before I leave we get to collect some interesting photons. But you never know - Nature decides. 


Thursday, August 6, 2015

First Observations

Visiting Las Campanas in winter means that weather somewhat occasionally does not cooperate with observational astronomy.  This storm that we're experiencing the last few days has been particularly harsh and unusual.
The clouds are low, the wind is strong, and we keep getting suckered by seeing clear skies at the edge of the cloud deck.
I planned for 8 nights at LCO expecting that at the worst about half would be a loss due to weather.  We saw some stars for an hour or two on my first night, and not a thing since.  Unlike the rays of sunshine in the photo above there's no good weather news on the horizon.  Despite this, we've been keeping busy with regular work and taking advantage of other things LCO has to offer.

Instead of stars, galaxies and planets, I have other observations for you:

Observation #1:  Astronomers are weather bugs.

The last four nights have been spent in part staring at our weather monitors, and trying to guess if there will be a break in the clouds between the multicolored bands coming in off the coast.

Observation #2: The viscachas know what's up.

Warm furry coat, hiding from the wind, protected under the eaves, and facing the sunset. 

Observation #3: Clouds are bad for observational astronomy, but utterly stunning for sunsets in the Atacama.

When I saw this sight out the window of my room, I dropped my toothbrush, grabbed my camera and ran to capture the sight.

Observation #4:  There is still plenty to do to keep ourselves busy productive members of the Observatory.


Views: Magellan Clay Telescope by Cynthia Hunt
Click and drag the photosphere above to explore inside the Magellan Clay Telescope!

The most important observation of the last four nights is that the LCO Telescope Operators are golden. They are incredibly knowledgable, there to help you get your work done, not to mention warm and friendly.  They indulged my questions, and even moved the telescopes around so I could take the best photospheres and movies.

Many people here have told me that working at LCO is like being part of a family, and it's absolutely true.  What a place to do science!


Wednesday, August 5, 2015

Not-Observing

In all of my previous posts, I've been observing. (Although in my last post I was observing at Gemini North, not Las Campanas Observatory.) On this run at LCO, I am doing a lot of not-observing. I arrived on Monday to a partly cloudy sky, and got to watch my office mate Serge Dieterich get a few hours of observations on the Baade telescope with FIRE. I also got to chat with the FIRE instrument PI, Rob Simcoe, which was pretty cool; he was making some upgrades to the computers system running FIRE to try to make the read-out time faster. But unfortunately, the decent weather did not last, and Serge lost much of the second half of the night. Conditions have not improved.

Last night was my first of two nights on the MIKE spectrograph, and instrument I've written about before. I'm here with Alex Ji, a graduate student at MIT working with another Las Campanas Belle, Anna Frebel. (Alex is on Twitter, @alexanderpji, you should follow him!) The plan was to split four MIKE nights, with my targets getting priority the first two nights, and Alex and Anna's targets getting priority the second two nights. This is a great partnership, because (in theory) it spreads out the weather risk a bit, and I got a chance to give Alex some lessons on using MIKE before he is by himself for the last two nights (when I'm going home). Alex is super enthusiastic, and we came up on Tuesday afternoon and did most of the calibration images needed for both our data reductions for all four nights.

Alex putting the diffuser in so we can take milky flat calibration frames. Photo credit: Cindy Hunt Benson.
 We arrived after dinner on Tuesday ready to collect photons. The weather had other plans, though.

LCO on Tuesday afternoon. Looks great!
Alex, before we walked up to the Magellans on Tuesday evening. Does not look great.

video

Above is an all-sky camera time lapse of last night. You can see a few sucker holes at the beginning of the night, and even the Milky Way through the clouds. But then it just gets worse...and worse...and worse. You can't even see the nearly-full moon rise near the middle of the night. Boo.

Tonight is even less promising. Luckily it isn't raining or snowing, but the clouds are certainly thicker and the wind is certainly higher. Looking at the satellite imagery,



makes it seem like we might see some clear-ish sky by the end of the night, but we'll have to wait and see. The LCO staff are not so optimistic -- they covered the instruments inside the dome, as well as several other electronics, with plastic covers, in preparation for precipitation.

Non-observing is part of being an observer, particularly a "classical" (not queue; you have to come do the observations in person yourself) and "ground-based" observer. Luckily for me, LCO is a lovely place to hang out and work and chat with interesting people.
Astronomers eating! Clockwise from back left: Alex Ji, Serge Dieterich, me, Andrew Newman,
Gwen Rudie, Cindy Hunt Benson. Photo Credit: Francesco Di Mille , with Serge's phone.
We're extra lucky to have Dr. Cindy Hunt Benson visiting LCO this week. She is the social media coordinator/promoter for Carnegie Astronomy, and has been doing an AMAZING job on Twitter and Instagram and Facebook, showing off all the interesting research and discoveries related to Carnegie Astronomy. Really, you need to go look at those social media accounts to get the best picture of Carnegie Astronomy possible. You should at least check out Cindy's Pluto Plate video -- so cool! Look out for a post from Cindy on this blog soon. She had the idea to take a time lapse video of us working last night:


which is a riff of a video Anna Frebel made a few years ago. Unlike Anna, we were not-observing, but we still got a lot of work done, and had fun! Can you spot the Quadritos?