Above: The NIRPS instrument is installed on the 3.6 meter telescope of the Silla Observatory, in Chile. Below: Specter taken by NIRPs during the preliminary tests of the Star Proxima of the Centaur, our closest neighbor, in June 2023.
Credit: Etienne Artigau
A new infrared spectrograph installed in Chile, the NIRPs, reveals its first results in the detection of exoplanets and their atmospheres.
The Near-Infrared Planet Searcher (NIPS) marks a new step in exploring the universe with the publication of its first scientific results in the journal Astronomy & Astrophysics. This high-resolution spectrograph, specially designed to detect exoplanets and analyze their atmospheres, represents a major technological advance in the search for habitable worlds beyond our solar system.
A hyperperforming instrument installed in Chile
Operational since April 2023, the NIRPs is installed on the 3.6 meter telescope of the Silla Observatory in Chile. This instrument is the fruit of an exceptional international collaboration bringing together more than 140 specialists from six countries: Canada, Switzerland, Spain, Portugal, France and Brazil, with the support of the European Southern Observatory (ESO). The Canadian team, notably that of the Mont-Mégantic Observatory and the Trottier Institute for Research on Exoplanets at the University of Montreal, played a crucial role in this project.
The specificity of the NIRPs lies in its ability to observe in the nearby infrared, which makes it particularly effective to study the cold and red stars called dwarf M. These stars, the most numerous of our galaxy, mainly emit their light in the infrared, making the Nirps ideal for detecting small planets similar to the earth around these stars.
Unique technological synergy
One of the most remarkable innovations of the NIRPS is its ability to operate in tandem with Harps (High Accuracy Radial Velocity Planet Searcher), a spectrograph that has observed in the visible and operates on the same telescope since 2003. This combination allows you to simultaneously observe the same star in the visible and the infrared, offering a rare capacity to distinguish the real planetary signals of ” noise »caused by stellar activity such as eruptions, stains or magnetic activity.
The instrument is also equipped with an adaptive optical system which corrects terrestrial atmospheric distortions, thus improving the quality of observations while maintaining a compact and efficient design. This technology makes it possible to achieve remarkable precision of the order of the meter per second, comparable to the best instruments operating in the visible.
A sophisticated detection method
The NIRPs uses the radial speed method to detect exoplanets, by measuring the tiny back and forth movements of a star caused by the presence of an orbit planet. Detecting a planet as light as the earth around a dwarf M represents a considerable challenge, requiring precision of around 3.6 km/h. According to René Doyon, the project’s main co -searcher and professor at the University of Montreal, “for the first time, we reach a precision below the meter per second in infrared, comparable to that of the best instruments in the visible. »»
Beyond planetary detection, the NIRPs excels in the analysis of the atmospheres of exoplanets thanks to its infrared sensitivity which makes it possible to identify key chemical signatures such as water vapor, helium or methane.
The first scientific results of the NIRPs
The first results of the NIPS already demonstrate its scientific power. A Spanish team led by Alejandro Suárez Mascareño confirmed the existence of Proxima Centauri B, a planet similar to the land located in the habitable area of our nearest star. This team also detected clues of a second planet even less massive around the same star, stressing the remarkable sensitivity of the NIRPs to low -mass planets.
At the same time, a study by Romain Allart, a postdoctorate researcher at the University of Montreal and the Irex, revealed the presence of a helium gas tail escaping from the atmosphere of Wasp69 B, an exoplanet of the mass of Saturn. This detailed observation provides new crucial information on the evolution of planetary atmospheres under the effect of the intense stellar radiation.
A promising future for exoplanetary research
In exchange for the construction of the instrument, the consortium obtained 725 observation nights guaranteed from the ESO, representing 40 % of the time of the telescope. This exceptional allowance allows the team to receive new data daily and to pursue three main objectives: to search for planets around the dwarfs M, to measure the mass of known planets and to study the atmospheres of various exoplanets.
NIRPs will play a strategic role in identifying the most promising targets for atmospheric observations with the James Webb space telescope, and later in the search for biosignatures with the future European giant telescope currently under construction. As the Main Cocheur of NIRPs, François Bouchy, of the Geneva Observatory, says, “NIRPS is the fruit of experience acquired with previous spectrographers, innovative technologies and exceptional international collaboration”.
This new generation of instruments opens up new perspectives in the quest for habitable worlds, bringing humanity closer to the potential discovery of signs of life beyond our solar system.
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The Nirps scientific team in the fall of 2024.
Credit: courtesy
About this study
“Nirps Joining Harps at ESO 3.6m: On-Sky Performance and Science Objectifs”, led by François Bouchy from the Geneva Observatory to University of Geneva, was published on July 29, 2025 in the magazine Astronomy & Astrophysics.
The team also includes 32 co-authorities and co-detesses from the Trottier de Research Institute on UdeM (IREX) exoplanets and the Mont-Mégantic Observatory, and 109 other co-authorities of Germany, Brazil, Canada, Chile, Spain, France, Portugal and Switzerland.