Category Archives: Other

A feast to the eyes and to the heart: the VLT as seen by a non astronomer

By Meghie Rodrigues

The first thing you notice when you approach the VLT (Very Large Telescope) is its size. No doubt this is ‘big science’ in all senses: the four main telescopes have mirrors measuring 8.2m in diameter and are housed in structures which are as tall as an eight floor building (25 m high) and as heavy as about a hundred Asian elephants (430 tonnes). It brings to mind that the old saying ‘bigger is better’ makes a lot of sense when it comes to optical astronomy – the bigger the mirrors used, the more light you get and the farther you can look into deep space.

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Two of the four main telescopes at the right and one of the auxiliary telescopes at the left

This is what I saw, along with other Brazilian journalists, in getting to Cerro Paranal, a mountain region located in the Atacama desert in northern Chile. The European Southern Observatory (ESO) runs a variety of telescopes in the region and the VLT is the biggest of them.

We were taken to more than 2,600 meters above the sea level in one of the driest places on Earth (lots of sunscreen, drinking water and winter clothing is highly recommended) where rain just falls for about two months a year and where you can see the clouds below your feet, kept from getting too close by the Andes range. Which is a good thing for observations: the lower the humidity in the atmosphere, the lower distortion you get in images – and the further you go from cities or places with artificial light, the darker and better it is to observe the sky. And yes, from the point of view of a Brazilian, nights are terribly cold at that altitude!

Days at Paranal are as bright as nights are dark, and the view of a rich diamond-studded black cloth extended high above your head during nighttime is a feast to the eyes and to the heart.

 

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Roof of the main telescope #2 (Kueyen) open to get the instrumentation ready for night observation

Named in Mapuche language – Antu (the Sun), Kueyen (the Moon), Melipal (the Southern Cross) and Yepun (Venus) – the telescopes can be used separately, each as a single instrument, or together, as what scientists call a ‘interferometer’. As such, it allows a closer look into many observation questions, including extra-solar planets – or planets outside our solar system –, the formation of stars and planetary systems as well as the surface of stars.

In talking to astronomers at Cerro Paranal, it wasn’t hard to see that ‘impressive’ applies not only to the size of the main telescopes but also to the science that comes out of them. The first image of an extra-solar planet, 2M1207, was one of them. Also, the oldest star we’ve seen in the universe up to now – which is said to be 13,2 billion years old, almost the age of the Universe itself – was found using the telescopes. Evidence of the accelerated expansion of the Universe also drew from many of the VLT observations.

 

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Mirror of the Kueyen telescope, 8.2m wide

So many hours of past and present observations are made by astronomers who are specialists in the many instruments VLT has – requested by other scientists from a wide range of fields in observational astrophysics spread all over the world. They give away their evenings and nights in a different kind of ‘star parties’: instead of our romantic idea of an astronomer peeping into a telescope in a cold night, they receive tons of data from different ultra-sensitive cameras installed in the telescopes. Barbara has given us an account of her own observations there some time ago and she gives us a great idea of how it all works. 🙂

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Astronomers in action in the VLT control room at the Interferometer console

It was, in the end, quite interesting to be able to see and think about some of the tendencies and routes ‘big science’ is taking in a world where scientific and political cooperation is key. Massive projects like the Thirty Meter Telescope, the Giant Magellan Telescope and ESO’s European Extremely Large Telescope rely on more than agreements between research institutions and universities – they also go for negotiation between governments and their institutions, taking the conversation to the arena of diplomatic relations. Conversation on this level means more solidity for projects, which is important especially when it involves billions of dollars or euros. After all, you can’t do ‘big science’ alone.

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A visit to Mars Academy

By Sandra

Imagine you get to school one day, and instead of sitting through a tough class of math or history, your duty is to control a NASA mission looking at yet unseen regions of Mars! Would you like that? Well, then welcome to the Mars Academy!

Mars Academy is an outreach project designed by a team of NASA astronomers to inspire students from the ‘City of God’ neighbourhood in Rio de Janeiro, by exposing them to the latest knowledge regarding the Red Planet and attempt to raise their interest in science and technology. The astronomers will work together with local teachers at the INPAR (Instituto Prebisteriano Álvaro Reis de Assistência à Criança e ao Adolescente) school to offer the students a week of hands-on lessons covering different topics within astronomy and planetary science.

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After the first days covering introductory lessons, the students will submit targets for observation for NASA’s HiRISE camera, which will be sent to mission control at the Jet Propulsion Laboratory in Pasadena, California. HiRISE is one of the most advanced instruments exploring our Solar System and has produced beautiful images of our mysterious neighbor. These novel images will bring new scientific knowledge and contribute to the progress in the field.

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Local scientists from Brazilian institutions, as well as two team members of GalileoMobile, will also participate in the experience and support the American team in their work with the students, taking care of language and logistics.

A team of film-makers will accompany the project and produce a documentary to share the students’ personal journeys of discovery and the lessons learned from this experience with other children, schools, and public around the world.

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As put by one of the leading astronomers of the project, Wladimir Lyra, “If we can inspire favela kids, if we can kindle that light and provide the seeds that will make them pursue science as a career and go to college, they will have broken the cycle. They will become success stories, their peers will see that it’s possible to achieve social mobility through education, and at some point we can turn the tide of the urban reality in Rio.”

Keep tuned to the Mars Academy facebook page for more information about the upcoming visit to City of God!

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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.

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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