TOI-1452 b: SPIRou and TESS reveal a super-Earth in a temperate orbit transiting an M4 dwarf
Creators: name: Cadieux, Charles
name: Doyon, René
name: Plotnykov, Mykhaylo
name: Hébrard, Guillaume
name: Jahandar, Farbod
name: Artigau, Étienne
name: Valencia, Diana
name: Cook, Neil J.
name: Martioli, Eder
name: Vandal, Thomas
name: Donati, Jean-François
name: Cloutier, Ryan
name: Narita, Norio
name: Fukui, Akihiko
name: Hirano, Teruyuki
name: Bouchy, François
name: Cowan, Nicolas B.
name: Gonzales, Erica J.
name: Ciardi, David R.
name: Stassun, Keivan G.
name: Arnold, Luc
name: Benneke, Björn
name: Boisse, Isabelle
name: Bonfils, Xavier
name: Carmona, Andrés
name: Cortés-Zuleta, Pía
name: Delfosse, Xavier
name: Forveille, Thierry
name: Fouqué, Pascal
name: da Silva, João Gomes
name: Jenkins, Jon M.
name: Kiefer, Flavien
name: Kóspál, Ágnes
name: Lafrenière, David
name: Martins, Jorge H. C.
name: Moutou, Claire
name: Nascimento, J. -D. do
name: Ould-Elhkim, Merwan
name: Pelletier, Stefan
name: Twicken, Joseph D.
name: Bouma, Luke G.
name: Cartwright, Scott
name: Darveau-Bernier, Antoine
name: Grankin, Konstantin
name: Ikoma, Masahiro
name: Kagetani, Taiki
name: Kawauchi, Kiyoe
name: Kodama, Takanori
name: Kotani, Takayuki
name: Latham, David W.
name: Menou, Kristen
name: Ricker, George
name: Seager, Sara
name: Tamura, Motohide
name: Vanderspek, Roland
name: Watanabe, Noriharu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Exploring the properties of exoplanets near or inside the radius valley provides insights on the transition from the rocky super-Earths to the larger, hydrogen-rich atmosphere mini-Neptunes. Here, we report the discovery of TOI-1452 b, a transiting super-Earth ($R_{\rm p} = 1.67 \pm 0.07$ R$_{\oplus}$) in an 11.1--day temperate orbit ($T_{\rm eq} = 326 \pm 7$ K) around the primary member ($H = 10.0$, $T_{\rm eff} = 3185 \pm 50$ K) of a nearby visual binary M dwarf. The transits were first detected by TESS, then successfully isolated between the two $3.2^{\prime\prime}$ companions with ground-based photometry from OMM and MuSCAT3. The planetary nature of TOI-1452 b was established through high-precision velocimetry with the near-infrared SPIRou spectropolarimeter as part of the ongoing SPIRou Legacy Survey. The measured planetary mass ($4.8 \pm 1.3$ M$_{\oplus}$) and inferred bulk density ($5.6^{+1.8}_{-1.6}$ g/cm$^3$) is suggestive of a rocky core surrounded by a volatile-rich envelope. More quantitatively, the mass and radius of TOI-1452 b, combined with the stellar abundance of refractory elements (Fe, Mg and Si) measured by SPIRou, is consistent with a core mass fraction of $18\pm6$ % and a water mass fraction of $22^{+21}_{-13}$%. The water world candidate TOI-1452 b is a prime target for future atmospheric characterization with JWST, featuring a Transmission Spectroscopy Metric similar to other well-known temperate small planets such as LHS 1140 b and K2-18 b. The system is located near Webb's northern Continuous Viewing Zone, implying that is can be followed at almost any moment of the year.
description: Published in The Astronomical Journal