Category Archives: Team Members

The observation run experience

By Barbara

Visiting a ground-based observatory for an observation run is a duty that most observational astronomers have to do at least once in their lifetime. I have always enjoyed my visits to observatories in Chile and the United States, even when I haven’t been able to observe because of clouds, snow or fire! After spending several nights observing at the 1.5 meter telescope at the CTIO observatory in Chile while doing my undergraduate studies, I decided to become an astronomer.134321_10102247707797355_7849930295589533709_o

I recently visited La Silla observatory, in northern Chile, to observe nearby low-mass stars. The north of Chile, with its Andes mountains and the Atacama desert (the driest on Earth), is one of the best sites for optical and near-infrared observations. The main enemy of ground-based observations is our atmosphere. It interacts with the light coming from celestial objects, modifying their primordial information or just blocks completely. Therefore, one way to avoid the atmosphere, apart from sending telescopes to space (like Hubble), is to built observatories at high altitudes and in dry places (to avoid water molecules and rain).10256571_10102246959202545_4285825102303161396_o

Since the 1960’s, telescopes from the USA and Europe have been being built in northern Chile. La Silla observatory is managed by ESO and is composed of several small and medium size telescopes. Unless your institution and/or research group has exclusive access to a telescope, preparing and submitting an observation proposal is the first step to gain access. In a nutshell, a proposal presents your scientific idea and why/how the instrument and telescope would allow you and your co-investigators to achieve your scientific goals. The submitted proposals are then divided by astrophysical topic and evaluated by expert referees. Usually, each telescope and each of its instrument configuration has a specific number of allotted observing hours each semester or year. The referees grade your proposal upon which it is accepted, refused or put on a waiting list for the respective period. This is a quite competitive process and often certain instruments and telescopes are more requested than others. Since the hours for each instrument configuration are fixed, many good proposals will get no observing time for the proposed semester.


The typical oversubscription factor for ESO telescopes is higher than 3 (meaning the total requested observation time exceeds the advertised available science time 3 times). Even an 8-fold oversubscription is not unheard-of, for example, the galactic bulge has an RA of ~18 hrs which means that objects towards the bulge could only be observed for a few months a year. Not all observatories allow the principal investigators of a proposal on site; for example, the Paranal observatory prefers that experts of each instrument and telescope gather the data for you. In that case your proposal needs a list of targets containing all the specifics on how and when to observe and under which conditions. Some observers also request dark time, i.e. no moon light, and completely clear skies. Other ones, like mine, are ok with thin cirrus clouds and moon light, since my research objects tend to be bright and numerous enough.11090944_10102254693852245_8908365082942400467_o

For this semester I was awarded 3 nights at the NTT telescope and the SofI spectrograph in early April 2015 to obtain near infrared spectra of low mass stars. To get to La Silla observatory, I flew first from Porto, Portugal, to Santiago, Chile’s capital city, followed by regional plane to La Serena, the closest city with an airport to the observatory. From there, an official ESO shuttle drove a couple of astronomers and me for about 3 hours up the Andes. At La Silla, I was welcomed by the staff, assigned me a room and given some basic information of schedules and rules. One important rule is to always stay hydrated and to use sun protection (hat, sunscreen lotion) if you go outside, since it is quite dry and hot. Another one is to inform the staff if you are planning to take a walk, and to take a walkie talkie with you. Silence is encouraged near the dorms, since several astronomers and technicians may have spent all night awake observing. At La Silla, each meal (breakfast, lunch, dinner, midnight lunch) has an specific schedule, but snacks are always available for the hungry astronomers in form of left overs, fruit, dairy products, bread, etc, in the fridges of the kitchen (a big favourite is the ice-cream machine!). The meals are cooked by an army of chefs (that love to sing cheese love-themed songs while cooking), and usually cover all foods satisfying the carnivorous and vegetarians.DSCF6130

If it is your first time with an instrument/telescope, you are expected to arrive at least one day before your observing run, to get comfortable with the instrument and meet with the instrument’s support astronomer, who can help you prepare your planned observation. This is quite important since the observatories and telescopes have different ways and formats to submit your list of observation objects to the telescope operator. The telescope operator is the person in charge of the telescope and instrument and will stay with you all night, she or he moves the telescope to the position of the object and makes sure to observe the right object under the specifications given in the observation list.10479301_10102250694591795_8389879405996506512_o

A basic observation list has a name, the right ascension and declination of each object, along with some configuration information for the instrument. In my case, since I was using a spectrograph, I had to specified the size of the slit as well as the spectral range wanted (or grism), the exposure time for each spectrum, and the total number of spectra for each object to achieve my scientific goals. During my run the support astronomer, George, explained to me that this information has to be given in an specific format file for SofI, and helped me to prepare and test these files before my observation run. I visited him and the astronomer using the instrument before my observation run at the control room to learn how to use the interface and the procedures and strategies involved in the observation. This is quiet common, but it is always better to first ask the current observer if you can visit the control room, since you are asking to hangout with her/him while she/he is working under sleep-deprivation conditions.DSCF6079

In the end my observation run went great. It took me a while to get used to the night schedule (I couldn’t sleep much during the day so I drank tons of coffee to stay awake) but I had no time losses due to weather, most of the nights were clear (only the first night had a few cirrus clouds), and I observed most of the objects on my list. There was only one problem during the observation run: the telescope didn’t want to point towards a star near the southern celestial pole (declination -82 degrees). It is still not clear why the telescope didn’t want to move there, since it should be possible. Other observers at the control room had also some issues with their telescopes and instruments, but overall, we were quite happy.11129693_10102266245033585_4829306996848828419_o

Because of transport schedules from La Serena to/from La Silla, I had to be on the mountain 3 days before my observation run, and stay for an extra day afterwards. During that time I met cool people from the staff and visiting astronomers, and visited a few other telescopes. I had interesting conversations about science and world-wide issues during my meals with fellow astronomers. I was lucky to meet old friends and acquaintances coming from all over the world for their observation runs. We visited the nearby petroglyphs after my observation run was over, and enjoy lúcuma flavor ice-creams together while watching the amazing landscape of the Andes. I watched the beautiful colors of the sunset, and before the moon rose, I was able to admire the Milky Way and the Magellan clouds. I have always enjoyed my visits to observatories, and this time was no exception.10922367_10102246959661625_4610839843001199540_o

When you wake up feeling old

by Jorge Rivero González

When you wake up feeling old“, a song by Wilco, one of my favourite bands, sounds in my head every morning when I open my eyes. Early in the morning, the gravity seems to pull harder and Neil Armstrong’s step feels tiny compared to the big step from my bed to the floor. From my bed, the distance to the bathroom looks like the whole Universe.

“This is by far the most tiring expedition of GalileoMobile”, Philippe, who has participated in all of them, told me the other day. “Or maybe we are just getting older”. Well, I guess both.

Activities with children early in the morning, one hour for having lunch, then rushing to the school again to get everything ready for the afternoon session with teachers. The night falls and so begin our star-parties that last for a couple of hours. We grab some dinner and then we come back to our lodging or to our next stop where we prepare the activities for the next day. This is our dayly routine.

“I’m too old for this stuff”, I think while I throw water on my face to wake up. The mirror is no liar. Just like the Sun, dark spots are appearing below my eyes and they are getting bigger everyday. I sigh. Don’t get me wrong, I’m loving it here but these are no holidays, as some people could think. This work rhythm is quite demanding.

“Jorge, hurry up, we are going to arrive late to the school”, someone yells on the other side of the door. I summon strength from somewhere inside me and get ready for a new adventure.

It’s showtime, folks!

Bay Lake

by Jorge Rivero González

The first week of GalileoMobile activities in Bolivia is over and we finally had our first day off in more than 10 days. Most people would use that day for resting a bit to get ready for the weeks ahead. However, we couldn’t miss the chance to learn a bit about the Pando region and its beautiful surroundings. Four of us decided to just sleep a couple of hours after a long trip from the Puerto Rico District to Cobija and woke up at 5 a.m. to visit the Bay Lake. As I like to say, we will sleep when we are dead.

The Bay Lake is located on the Reserva Nacional de Vida Silvestre Amazonica Manuripi and is one of the natural jewels of Bolivia. It is considered one of the best natural reservoirs of Amazon fishes and it shows a great diversity of flowers and animals. In its shores you can find the trails of tigers, wild pigs,  alligators, vipers, parabas, parrots, ducks, eagles and many other animals you can’t even imagine.

After three hours of travel by car, we had to sail the Manuripi river on a small motorboat to reach the lake. With Miguel, our host for the visit to the lake, on the steering wheel, we began our journey. We were quite excited: Mayte was trying to spot all kind of animals, especially the alligators. With her pristine vision, just like an eagle,  she always was the first one to detect their big eyes over the water surface. Philippe spent his time trying to learn how to steer the motorboat and also playing the Quena, a Bolivian flute. Felipe was trying to get the best takes he could get for our upcoming documentary. And I was completely amazed by the scenery.


The numerous trees on both river’s shores were crooked towards the water and seemed like they were greeting us with a kind bow. Birds were flying really close to the water and crossing our path all the time. The waves produced by the motorboat were gently caressing the small beaches across the river.

And then something magic happened. Suddenly, the colour of the water changed. We arrived on the Bay Lake. Like when you mix oil and water, you could really appreciate the water that belongs to each one of the lakes.  As we were sailing deeper on the heart of the lake, new vegetation appeared before our eyes. The water was black and crystal clear. Like a mirror, it reflected everything that was above it. For a while, we dreamed about spending the night on the lake for observing the stars. How wonderful would be to observe them reflected on the lake. A place with two skies.

We stopped on a small beach on the lake and had lunch. Felipe had the great idea that we should stop talking for a couple of minutes and tried to appreciate the sound of nature. The birds chants, the sound of the insects flying or the streams of water flowing were clearer than ever. We felt one with the lake.

We also walked a bit across the forest. We followed a narrow path guarded by thick vegetation. We walked for half an hour and reached nowhere. The trees were so tall that couldn’t have any reference to follow. Over there, you could feel the solitude of nature. We marched back using the same path. On the way back on the motorboat, we didn’t talk much, listening to nature and thinking about our experience on the lake.

Second week of activities here we come!