An international team of astronomers reported the discovery of a new “super-Earth” exoplanet using NASA’s Transiting Exoplanet Survey Satellite (TESS) instrument. The newly discovered alien world, designated TOI-1680 b, orbits an M-dwarf star about 50% larger than Earth and about 120 light-years away. The discovery was detailed in an article published July 11 on the preprint server. arXiv.

TESS searches about 200,000 of the brightest stars near the Sun to look for transiting exoplanets. So far, it has identified approximately 6,700 candidate exoplanets (TESS Objects of Interest, or TOIs), of which 363 have been confirmed.

In a recent research paper, a team of astronomers led by Mourad Gashui of the University of Liège in Belgium confirmed another TOI observed by TESS. Ghachoui and colleagues reported the identification of a crossover signal in the light curve of an inactive M dwarf known as TOI-1680. The planetary nature of this signal was confirmed by subsequent ground-based photometry, high-resolution imaging, and spectroscopic observations.

“We report the discovery and initial characterization of TOI-1680 b, a super-Earth orbiting a faint medium-sized dwarf (V=15.87),” the researchers write in the paper.

TOI-1680 b has a 1.46 Earth radius radius and an estimated mass of about 3.18 Earth masses, giving an average density of 5.5 g/cm ³ . The planet orbits its host star at a distance of about 0.03 AU every 4.8 days. The equilibrium temperature of TOI-1680b is estimated to be 404 K.

The main star TOI-1680 (also known as TIC 259168516) is a faint and inactive star of the M4.5 spectral type. It is about five times smaller and smaller than the Sun. The calculated distance to TOI-1680 is 121 light years, and the star’s effective temperature is about 3211 K.

The study found that TOI-1680 b has a transmittance spectroscopic measure (TSM) of 7.82. This result suggests that TOI-1680 b may be a suitable target for atmospheric characterization using the NIRSpec/PRISM instrument on the James Webb Space Telescope (JWST).

According to the transmission spectroscopy metric (TSM) by Kempton et al. (2018), TOI-1680 b may be a promising candidate for atmospheric characterization by JWST… Notably, among 63 targets, TOI-1680 b ranks thirteenth as the most suitable target for these studies.

Gachui’s team proposes measurements of the radial velocity of TOI-1680 b using the MAROON-X high-resolution fiber-fed optical stepped spectrograph on the Gemini North 8.1-metre telescope, in addition to studies of atmospheric properties. Such a study should provide a direct measurement of mass, which will be crucial for determining the composition of this planet. Source