The Near InfraRed Planet Searcher (NIRPS) is an instrument that was recently installed at the 3.6 meter telescope of the La Silla Observatory in Chile. Its design was carried out by an international collaboration led by the team of the Mont-Mégantic Observatory (OMM) and the Institute for Research on Exoplanets (iREx) of the University of Montreal and the Astronomical Observatory of the University of Geneva in Switzerland.
The Canadian team, which also includes the Herzberg Research Center for Astronomy and Astrophysics of the National Research Council of Canada and the Center for Optics, Photonics and Lasers (COPL) from Laval University, contributed to the conception and design of the NIRPS spectrograph. It is also in the premises of the COPL that Professor Simon Thibault and his team, in collaboration with the OMM and iREx team, conducted mechanical and optical tests.
The NIRPS spectrograph cryostat, which keeps the instrument at very low temperatures. Credit : Anne-Sophie Poulin Girard.
In January 2022, the NIRPS spectrograph was ready for its big trip. He left the laboratories of Laval University to travel to Chile, finally reaching the La Silla Observatory in March.
The spectrograph installation and testing phase might then begin. Anne-Sophie Poulin Girard, Hugues Auger and Guillame Alain, from Laval University, accompanied by Benjamin Kung, Alex Segovial and François Wildi, from the Astronomical Observatory of the University of Geneva in Switzerland, as well as Frédérique Baron, Philippe Vallée, Étienne Artigau and Charles Cadieux, from the Observatoire du Mont-Mégantic and the iREx, went on site to install the instrument and get it working before it might observe the sky for the first time.
We asked a few questions Etienne Artigau, Charles Cadieux et Frederique BaroniREx members who participated in these installation and testing activities.
Étienne Artigau (left), Charles Cadieux (center) and Frédérique Baron (right) with the NIRPS. Credit: Courtesy Photos (gauche et centre), Gaspare Lo Curto (right).
iREx: Why did you go to Chile? Who are you and what is your role in this project?
Stephen: I am a researcher at the University of Montreal and I am the scientific manager of the NIRPS project: I coordinate the scientific projects on the instrument. I am also very involved in data analysis and transformation of data that is taken with the NIRPS into useful measurements for astronomy research. However, it was not in this capacity that I took part in the mission last April. My role was then to assist Philippe Vallée, mechanical specialist, in the very last tests before cooling the instrument for the first time.
Charles : I am a doctoral student in astrophysics at the University of Montreal and a member of the NIRPS scientific team. I went to Chile, more precisely to the Observatory of La Silla, within the framework of the installation of NIRPS. My doctoral scientific project is devoted to the study of small temperate exoplanets. In particular, I try to measure their mass and their composition, which requires observations with an instrument such as the NIRPS.
Frederique: I’m the assistant manager of NIRPS. I went to Chile to be able to participate in the first phase of the installation of NIRPS. In particular, with Alex Segovia, we installed and tested the various electronic devices that control the systems installed in the cryostat, the sealed chamber that keeps the instrument at very low temperatures.
iREx: Tell us regarding your stay!
Stephen: First of all it started very badly! Due to the COVID epidemic, I had to do the PCR tests before departure… and my test was lost by the laboratory! After a few anxious moments on the phone, they were able to find me a quick test to do at the airport. Once in Santiago, I was finally able to get out of the airport hotel, to go to the Observatory residence which welcomes passing astronomers and enjoy the city a bit. The next day, departure for the Observatory of La Silla; a 500 km leap by plane to get to La Serena, a 2 hour journey by truck and finally the Observatory.
Once there, every day is alike and nothing marks the passage of time. We get up around 7am, and we mustn’t make too much noise, because there are colleagues who have just gone to bed in the neighboring rooms! There is a breakfast in the cafeteria of the Observatory and then we go to the telescope to work on the instrument.
A guacano at La Silla Observatory. Credit: Etienne Artigau.
The La Silla Observatory site is quite extensive and the telescope is nearly 2km from the rooms. A car is available to us, but we try to walk when the weather permits, there are guanacos all over the area and it’s an absolutely magnificent setting!
There are a host of small tasks to perform on the NIRPS instrument. At the time of my visit in April, the instrument was under vacuum and we were regarding to start the cooling phase so that the temperature of the spectrograph drops to almost -200℃. The slightest leak in the cryostat might seriously compromise the project, so we make sure to eliminate them all!
When the evening came, I took part in the observations several times with the technicians during the first half of the night. It was very useful for me, because we will have to conduct many nights of observations over the next five years, both in person and remotely.
Charles : It was the first time I went to the Observatory, where I spent two weeks. A good part of my time was devoted to learning the operation of the 3.6 meter telescope, the largest on site, where the NIRPS is installed. I familiarized myself with the instrument’s control room, where the observation and calibration sequences are launched. During my stay, among other things, I carried out routine checks of the NIRPS cooling system, optimized the instrument’s calibration sequence and helped to realign the entry of one of the optical fibers, a crucial operation to ensure the proper functioning of NIRPS.
iREx: What interests you in this project? What aspect do you find the most exciting?
Stephen: In exchange for designing the instrument, our team got 720 nights spread over 5 years, which is absolutely huge! It will allow us to do what no other team in the world can afford in terms of the scale of observation projects.
Data analysis also amuses me a lot! It’s like doing a wordle or a sudoku, but on a much larger scale. We know that in terabytes of data hides the signal of a planet that might harbor life… all that remains is to decipher it.
Charles : The NIRPS will be one of the most powerful infrared spectrographs in the world. It will also be possible to operate the NIRPS simultaneously with the world-renowned HARPS spectrograph, a complementary instrument, sensitive to visible light, which has been in service for many years at the same telescope. Simultaneously obtaining the spectrum of a star in the visible and infrared makes it easier to identify signals related to its magnetic activity, which can sometimes be confused with signals from exoplanets. The NIRPS + HARPS combo will therefore be very effective for studying exoplanets. For example, we will be able to determine the chemical composition of the atmosphere of exoplanets similar to Earth.
iREx: What was the biggest challenge?
Charles : In my case, the biggest challenge was to quickly learn how NIRPS and La Silla facilities work.
Frederique: The biggest challenge for me didn’t come during my stay at La Silla, but more before (and following!). The installation of NIRPS at La Silla required the presence of several people on site in addition to constant interaction with colleagues in Montreal and Geneva. The different phases of installation of the instrument requiring people with different skills, it was quite a headache to organize the most optimal schedule. In the end, everything went well and we even finished our work a little early!
iREx: What did you like the most regarding your experience?
Timelapses at La Silla Observatory. Credit : Etienne Artigau.
Stephen: The nights are absolutely magical, especially when the moon goes down! The altitude of La Silla is optimal for observation, because the higher the oxygen deficit makes the eye less sensitive to the low luminosity of the stars. I had fun making time-lapse videos (timelapse) to show the atmosphere of the nights on the mountain.
Charles : I loved being on the site, which is located in the middle of the desert at an altitude of 2400 meters. I had wonderful encounters there with astronomers from all over the world. It was a great honor to have participated in the preparation phase of NIRPS.
Frederique: The skies of La Silla are absolutely stunning! Being used to the Observatoire du Mont-Mégantic, I was particularly happy to be able to look at the stars outside without getting cold!
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