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Astronomers have found an exoplanet that could serve as a benchmark in future studies.
It's a rocky planet orbiting an M-type star, and though these planets are plentiful, this one could serve as a benchmark for understanding other M-dwarf exoplanets and their atmospheres.
According to the authors of a new study, this new exoplanet could serve as "a reference system for highly irradiated rocky planets." The new research is titled "TOI-4616 b: a benchmark Earth-sized planet transiting a nearby M4 dwarf," and it's been submitted to the Monthly Notices of the Royal Astronomical Society.
The lead author is Francis Zong Lang, a doctoral researcher at the Center for Space and Habitability at the University of Bern in Switzerland.
The paper is currently available at arxiv.org. With more than 6,000 confirmed exoplanets, our understanding of the exoplanet population is becoming more complete.
There are still observational biases in the results, but some trends are emerging.
One thing that's becoming clear is the relationship between M dwarfs and rocky exoplanets. Research shows that M dwarfs are the most prolific hosts for terrestrial exoplanets.
In fact, many of these stars host multiple rocky planets, with the TRAPPIST-1 system being the most well-known example: it hosts seven rocky planets. All of these rocky worlds around dim stars open up a window to studying exoplanet atmospheres. This artist's illustration shows the TRAPPIST-1 system.
It's a red dwarf that host seven rocky exoplanets, and four of them are likely in the habitable zone.
The star's powerful flaring is represented in the image.
The JWST hasn't found any evidence of atmospheres around any of these worlds yet.
Image Credit: NASA, ESA, CSA, STScI, Joseph Olmsted (STScI) "Rocky exoplanets are particularly abundant around M-type stars," the authors of the new research write.
"Their small radii and low luminosities provide favourable conditions for detecting transiting terrestrial planets and probing their atmospheric properties." "We report the discovery and statistical validation of TOI-4616 b, an Earth-sized planet transiting a nearby mid-M dwarf observed by the Transiting Exoplanet Survey Satellite (TESS)," the authors write. The thing about rocky planets around M-dwarfs is that they typically orbit very close to their stars.
This puts them in atmospheric peril, as powerful radiation and flaring can strip their atmospheres away.
It's even worse.
M-dwarfs take up to 1 or 2 billion years to reach the main sequence.
Prior to that, their luminosity is much higher, putting addition dissipative pressure on the atmospheres of any rocky planets orbiting them. There's some good news for these atmospheres, though.
While primordial hydrogen-rich atmospheres are easier to remove, thicker atmospheres dominated by CO2 might resist dissipation.