Category Archives: Other

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

The Moon was fighting the Sun

By Fabio

The magic has happened again: deep, tongue-tying darkness in the middle of a sunny day.

It was really cold: my hands started freezing as soon as I took off my gloves to capture this day in some pictures. FADS5406

Adventalen, March 20, 2015. Credit: Fabio Del Sordo / GalileoMobile

The light began changing gradually, from ten in the morning onwards, turning the surrounding mountains from white into a sort of yellow mixed with red.

A hot-air balloon was sailing the south-eastern blue sky, where a sundog was shining. Then it moved towards the Sun, perhaps trying to help the Moon to obscure our star. But this traveler of the air didn’t dare to interfere with the fight, and thus passed below the Sun, kept moving south, and finally disappeared behind the ridges of arctic mountains. FADS5405

A hot-air balloon crossing the sky near a sundog. Credit: Fabio Del Sordo / GalileoMobile

I was checking the solar disk through my solar-filter glasses, taken at UNIS yesterday morning. The Moon was about to win the fight with the Sun, which did surrender, with a final breath, some minutes past eleven. FADS5423

The Moon passing between me and the Sun. Credit: Fabio Del Sordo / GalileoMobile

The whole valley suddenly turned into an unknown place, a landscape of one of the extraterrestrial lands that humans will, one day, discover, touch, explore. FADS5430

The sky during the totality of the solar eclipse On the left, Venus is visible. Credit: Fabio Del Sordo / GalileoMobile

Then, the magic: our star took back its place in the terrestrial sky, the Moon was convinced to give up the fight.

The Sun irradiated the humans with its light and love. One can entirely understand them only after a storm of darkness. FADS5432

After some minutes of darkness the Sun is back and keeps shining in the sky. Credit: Fabio Del Sordo / GalileoMobile

You don’t need fancy equipment to observe a solar eclipse!

by Jorge

It’s been almost ten years since the last time I observed a solar eclipse. Sadly, on the place I lived back then, La Laguna in Tenerife, it was only a partial eclipse. I had no better luck this time.

Nowadays, I live in small town of France called Besançon. Apart from good wine and cheese there is an old observatory where they organized a public observation of the partical eclipse this morning.

Tons of people observing the solar eclipse in Besançon, France. Credit: GalileoMobile

Tons of people observing the solar eclipse in Besançon, France. Credit: GalileoMobile

Hundreds of people gathered around the Besançon Observatory to observe it, including students with their teachers.

Solar Eclipse projection. Credit: GalileoMobile

Solar Eclipse projection. Credit: GalileoMobile

Some people brought their own telescopes, binoculars or specials glasses, all with the appropriate filters, to safely look at the Sun. There was even a man taking pictures with a webcam connected to a laptop!

Taking pictures of the solar eclipse. Credit: GalileoMobile

Taking pictures of the solar eclipse. Credit: GalileoMobile

People who didn’t have special filters just made a projection of the Sun with a small telescope on cardboards. That is what we do during the GalileoMobile activities to safely observe the Sun. “There is a small black dot on the surface of the Sun”, I heard. “That is a sunspot, a region of the Sun’s surface that is colder and therefore appears darker”, a teacher replied. “Wooow”, the students yelled.

But you don’t need fancy equipment to observe the eclipse. People were using his hands or carving holes in boxes to make a pinhole camera to project the image of the Sun onto papers. You can do the same with the leaves on the trees but good luck to find any leaf on trees at the end of winter in France!

Kids using slotted spoons to observe the solar eclipse. Credit: GalileoMobile

Kids using slotted spoons to observe the solar eclipse. Credit: GalileoMobile

My favourite method was the one used by a bunch of kids that were holding slotted spoons in one hand and a paper on the other one to observe the eclipse. Next time I won’t forget my pasta strainer!

I spent most time observing people though. Just like Amelie liked to observed people when they were watching movies at the cinema, I liked to see the reactions of people when they look through a telescope. Try it, it’s great!

Well, at the end it was fine observing the partial eclipse, at least we got a smile from the Sun. Not bad for the International Day of Happiness!

Next time, my pasta strainer and I, will travel anywhere in the world to see a total eclipse. I wish I were in Svalbard islands with my friend Fabio today!