• DOI:10.1051/0004-6361/202038160
• Corpus ID: 215754286

Precise mass and radius of a transiting super-Earth planet orbiting the M dwarf TOI-1235: a planet in the radius gap?

@article{Bluhm2020PreciseMA,
  title={Precise mass and radius of a transiting super-Earth planet orbiting the M dwarf TOI-1235: a planet in the radius gap?},
  author={P. Bluhm and Rafael Luque and N{\'e}stor Espinoza and Enric Pall{\'e} and Jos{\'e} Antonio Caballero and Stefan Dreizler and J. H. Livingston and Savita Mathur and Andreas Quirrenbach and Stephan Stock and Vincent Van Eylen and G. Nowak and Eric D. Lopez and Sz. Csizmadia and Mar{\'i}a Rosa Zapatero Osorio and P. Sch{\"o}fer and Jorge Lillo-Box and Mahmoudreza Oshagh and E. Gonz{\'a}lez-{\'A}lvarez and Pedro J. Amado and David Barrado and V. J. S. B{\'e}jar and Bryson L. Cale and Priyanka Chaturvedi and Carlos Cifuentes and William D. Cochran and Karen A. Collins and Kevin I. Collins and M. Cort{\'e}s-Contreras and Enrique D{\'i}ez Alonso and Mohammed El Mufti and Andrea Ercolino and Malcolm Fridlund and Eric Gaidos and R. A. Garc{\'i}a and I. Georgieva and Luc{\'i}a Gonz{\'a}lez-Cuesta and Pere Guerra and A. P. Hatzes and T Henning and E. Herrero and Diego Hidalgo and G. Isopi and S. V. Jeffers and J. M. Jenkins and Eric L. N. Jensen and Petr Kab{\'a}th and A. Kaminski and J. Kemmer and J. Korth and Diana Kossakowski and Martin K{\"u}rster and Marina Lafarga and Franco Mallia and David Montes and Juan Carlos Morales and M. Morales-Calder{\'o}n and Felipe Murgas and Norio Narita and Vera Maria Passegger and S. Pedraz and Carina M. Persson and Peter P. Plavchan and Heike Rauer and Seth Redfield and Sabine Reffert and Ansgar Reiners and Ignasi Ribas and George R. Ricker and Cristina Rodr{\'i}guez-L{\'o}pez and A. R. G. Santos and Sara Seager and Martin Schlecker and A. Schweitzer and Yutong Shan and M. G. Soto and J{\'a}n {\vS}ubjak and Lev Tal-Or and Trifon Trifonov and Siegfried Vanaverbeke and Roland K. Vanderspek and Justin M. Wittrock and Mathias Zechmeister and Farzaneh Zohrabi},
  journal={Astronomy \& Astrophysics},
  year={2020}
}

• P. Bluhm, R. Luque, +81 authors F. Zohrabi
• Published 13 April 2020
• Physics, Geology
• Astronomy & Astrophysics

We report the confirmation of a transiting planet around the bright weakly active M0.5 V star TOI-1235 (TYC 4384–1735–1, V ≈ 11.5 mag), whose transit signal was detected in the photometric time series of sectors 14, 20, and 21 of the TESS space mission. We confirm the planetary nature of the transit signal, which has a period of 3.44 d, by using precise RV measurements with the CARMENES, HARPS-N, and iSHELL spectrographs, supplemented by high-resolution imaging and ground-based photometry. A comparison of the properties derived for TOI-1235 b with theoretical models reveals that the planet has a rocky composition, with a bulk density slightly higher than that of Earth. In particular, we measure a mass of Mp = 5.9 ± 0.6 M⊕ and a radius of Rp = 1.69 ± 0.08 R⊕, which together result in a density of ρp = 6.7− 1.1+ 1.3 g cm−3. When compared with other well-characterized exoplanetary systems, the particular combination of planetary radius and mass places our discovery in the radius gap, which is a transition region between rocky planets and planets with significant atmospheric envelopes. A few examples of planets occupying the radius gap are known to date. While the exact location of the radius gap for M dwarfs is still a matter of debate, our results constrain it to be located at around 1.7 R⊕ or larger at the insolation levels received by TOI-1235 b (~60 S⊕). This makes it an extremely interesting object for further studies of planet formation and atmospheric evolution.