How Many Planets Orbit Our Nearest Neighboring Star?

So far, some of the most promising places to search for extraterrestrials have remained, mainly hidden from astronomers. Now, an instrument that changes the situation called NIRPS (plane researcher near infrared) leads the search for the most attractive targets of the cosmos: potentially in the shape of the earth around the red dwarf stars nearby.

Red dwarfs, or databases, are the most tempting places to search for extraterrestrial lands because these are the most abundant and durable stars. They constitute the majority of the stars of the Milky Way and shine with a slow thermonuclear simmer which should allow them to live exponentially longer than most, for example, for 14 billions of years, or 1000 times the current age of the universe.

But the dwarf Ms are also the smallest and thinnest stars, so that they and their planets can be difficult to detect and inspect. Enter NIRP, an instrument built to measure to unravel subtle signs of otherwise hidden worlds by making unrivaled high precision measurements of dnin m, which emit most of their light in infrared and almost infrared wavelengths.

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“I think that we are at the golden age of M Dwarfs, where they offer a huge amount of possibilities – this is the best place to detect small planets in the size of the earth,” explains Natalie Hinkel, planetary astrophysicist of Louisiana State University, who is not a member of the NIRPS team.

The nine border

Nirs can find planets via the radial speed method (RV), which searches for the tiny gravitational tug that they exercise on their stars. This tug always changes the speed of the star so slightly, which in turn almost indistinguishable the color of its light. When an orbit planet draws its star closer to the earth, the light of the star moves slightly at the blue end of the spectrum of our telescopes; When the planet pulls its star, the light of the stars moves slightly towards the red end. The red cyclic blue stellar oscillation which is the RV signature of a small orbit world around a dat m corresponds to a speed shift less than one meter per second. Dwarfs are particularly well suited to RV Planet surveys because their low masses can lead to larger and more obvious tugs from all the small accompaniment worlds.

René Doyon, professor at the University of Montreal and Co-Principale des Nirp, contextualized the breakthrough in a press release: “For the first time, we can reach the precision of the radial speed of the sub-meter by second in the infrared.” This means that nirp can see a distant star zooming in space and discerning a change in its speed which is equivalent to the speed of a quiet walk in the park.

NIRPs and other RV -based projects are spectrographs, similar to prisms attached to existing telescopes. Like a prism difference in white light in a rainbow of colors, a spectrograph divides the light of the stars in its constituent wavelengths, producing a spectrum of arc thieves. The “digital imprints” of different atoms and molecules in the atmosphere of a star can be printed on its spectrum, and they serve as reference marks for planet hunters in search of tiny speed shifts.

Last month, in the first outings of Science Nirps since the start of its operations in April 2023, the researchers reported their meticulous observations of the Red Dwarf Proxima Centauri, the nearest neighboring star of the solar system, located only 4.2 light years. The NIRPs helped confirm the presence of Proxima Centauri B, a planet about the earth’s mass in the habitable area of ​​the star where liquid water could exist. He also confirmed another smaller planet, Proxima Centauri D, which is only a third the mass of the earth. Finally, the NIRPs refuted the existence of another potential planet which was supposed to be in the system, Proxima Centauri c.

Although two confirmations – and a dismissal – of allegedly claimed worlds do not make many major titles, the result of the NIRP is a remarkable VR feat and a major advance in the understanding of the true nature of the planetary system closest to ours.

However, Proxima is a unique case, and improved VR instruments like the NIRP are ready to discover a bigger and richer treasure of worlds around the nine n nearby. Such stars in our own galaxy, astronomers believe that perhaps one in five planets carried in their habitable areas.

This embarrassment of planetary wealth means that NIR cannot be alone at the forefront of RV surveys. A large part of his work is increased by complementary observations of another spectrograph called the planet researcher at high precision radial speed, which is attached to the same telescope as the NIRP at the Silla observatory in the Chilean desert of Atacama. Harps has been engaged in a hunt for planets for RV since 2003, although it looks in the optical light rather than on a nearby infrared, as does the NIRP. Together, they can distinguish the real planets from the false positives caused by the enlightening rockets, the spots and the magnetic activity of a star.

It is therefore not surprising that the Duo Nirps-Harps is the most oversized instrument at the Silla Observatory, with a “combined request of 3,277 hours” over a seven-month observation period, according to François Bouchy, an associate professor in the Astronomy Department of the University of Geneva and Princer-Princer-Princer.

Expand the exoplanet catalog

Until now, whether in quasi-infrared or optics, the RV technique has revealed more than 1,100 of the nearly 6,000 exoplanets currently known. It is second after the detection method of the transit planet, which seeks hollows in the light of a star while a planet in orbit passes in front of it, like a butterfly of butterflies in silhouetté against a flame. Overall, the transit method gave nearly 4,500 exoplanets – almost 75% of the worlds cataloged in the archives of NASA exoplanets.

But while transits can now overshadow the VR as a method of planetary discovery, RV is always an important tool for follow -up studies. The NIRs and his parents can defeat the ball of the ball for thousands and thousands of planetary candidates found via transits, separating the real planets from the myriad of false potential positive positives posing as world transit. These new generation RV instruments are also essential to reveal crucial details – above all, the estimated mass of a planet – which transit cannot generally solve.

Mass measurements can be essential for the distinction between the types of planets of similar size

However, Nirps is just the most recent in a constantly increasing family of Planet-Finders. He is joined in his exploratory efforts by others such as the research of Exoplanet NN-Explore with Doppler spectroscopy (NEID), another nearly precise infrared spectrograph sponsored by NASA and the National Science Foundation and operating on the 3.5-meter Wiyn Telescope at Kitt Peak National Observator in Arizona. Similar to NIRP, a large part of Neid’s work consists in validating the possible planets provided by other installations; The instrument recently confirmed that candidates from the satellite mission of survey of exoplanets in transit of NASA (Tess) and the GAIA mission of the European Space Agency (ESO).

Neid observes a narrower wavelength range than the Nirp, although it extends to the visible light beach from deep blue to infrared. It can measure the changes in the speed of a star which are tied with the ramp speed of an infant, almost 30 centimeters per second, although this does not include the wider range of NIRP through the infrared. However, as Doyon explains, “detect [RV signal of] The earth around the sun ”would require even more clear precision of about 10 centimeters per second.

Achieving such extreme precision is not yet common currency, but an existing VR instrument is getting closer: the espresso (spectrograph scale for rocky exoplanet and stable spectroscopic observations), which is installed on the very large eSO telescope (VLT) in Chile, can reach a sensitivity of around 20 centimeters per second. It is precise enough to find worlds smaller than the earth, including Barnard B, which orbit the star of Barnard, the unique system closest to the earth. (Proxima Centauri is part of a triple star system.)

Barnard B is unlikely to look a lot like the earth: its orbit is 20 times smaller than that of Mercury, which gives it a year of about three days and an estimated temperature at around 125 degrees Celsius.

Horizons of another world

Although NIRP can find many worlds, because it generally observes the host star of a planet rather than a planet itself, the instrument cannot seek any direct sign of extraterrestrial life. But that shows that astronomy, like history, is cyclical. Just as other observatories have chosen candidates for NIRPs and other RV spectrographs to explore, these instruments will also select promising planetary targets for atmospheric studies by powerful installations such as the James Webb space telescope.

NIRPs will also identify interesting exoplanets for new generation observatories such as the Roman space telescope Nancy Grace Roman of NASA, which can be launched from 2026, and the next extremely large telescope of ESO (ELT), which is built at the top of Cerro Armazones in Chile and will become the largest telescope in the world later.

Like all revolutionary technologies, NIRPs is already inspiring successors: namely a follow-up project called Andes (spectrograph of high dispersion failure failures), which is being developed for the ELT in the aim of the light analysis of the planet’s accommodation stars, but also of certain potentially habitable planets themselves and to survey them potentially for biosignes. “Andes is nir on steroids,” explains Doyon.

Further above the cosmic horizon, the planets picked up by the Nirs can be traveled by the next-following-The generation projects, such as the NASA habitable world observatory, which is envisaged as the very first space telescope specially designed to answer the most urgent question of science: what only are we, really?