TOI-1468: A system of two transiting planets, a super-Earth and a mini-Neptune, on opposite sides of the radius valley

Chaturvedi, P.; Bluhm, P.; Nagel, E.; Hatzes, A. P.; Morello, Giuseppe; Brady, Madison; Korth, J.; Molaverdikhani, Karan; Kossakowski, D.; Caballero, J. A.; Guenther, E. W.; Πάλλη, Ε.; Espinoza, N.; Seifahrt, Andreas; Lodieu, N.; Cifuentes, C.; Furlan, Elise; Amado, P. J.; Barclay, Thomas; Bean, Jacob L.; Béjar, V. J. S.; Bergond, G.; Boyle, A. W.; Ciardi, David R.; Collins, Karen A.; Collins, Kevin I.; Esparza-Borges, E.; Fukui, A.; Gnilka, Crystal L.; Goeke, R.; Guerra, P.; Henning, Th.; Herrero, E.; Howell, Steve B.; Jeffers, S. V.; Jenkins, Jon M.; Jensen, Eric L. N.; Kasper, David C.; Kodama, Takanori; Latham, David W.; López-González, M. J.; Luque, R.; Montes, D.; Morales, J. C.; Mori, M.; Murgas, F.; Narita, Norio; Nowak, G.; Parviainen, H.; Passegger, V. M.; Quirrenbach, A.; Reffert, S.; Reiners, A.; Ribas, I.; Ricker, G.; Rodrı́guez, E.; Rodríguez‐López, C.; Schlecker, Martin; Schwarz, Richard P.; Schweitzer, A.; Seager, Sara; Stefánsson, Gumundur Kári; Stockdale, C. J.; Tal-Or, L.; Twicken, Joseph D.; Vanaverbeke, Sigfried; Wang, G.; Watanabe, David; Winn, Joshua N.; Zechmeister, M.

doi:10.1051/0004-6361/202244056

Cited by 12 publications

(2 citation statements)

References 145 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We attribute the differences in measured planet radii to the fact that more TESS data became available between the publication of those systems and this work, leading to a transit signal that has a higher S/N and is more robust against systematics. Specifically, Gan et al (2022) did not have access to TESS sectors 44 and 45 for their analysis of TOI-530 b, Reefe et al (2022) did not have access to TESS sector 62 for their analysis, and Chaturvedi et al (2022) did not have access to TESS sector 57 for their analysis.…”

Section: Updated Planet Radiimentioning

confidence: 99%

Metallicities and Refined Stellar Parameters for 52 Cool Dwarfs with Transiting Planets and Planet Candidates

Gore,

Giacalone,

Dressing

et al. 2024

ApJS

View full text Add to dashboard Cite

We collected near-infrared spectra of 65 cool stars with the NASA Infrared Telescope Facility and analyzed them to calculate accurate metallicities and stellar parameters. The sample of 55 M dwarfs and 10 K dwarfs includes 25 systems with confirmed planets and 27 systems with planet candidates identified by the K2 and TESS missions. Three of the 25 confirmed planetary systems host multiple confirmed planets and two of the 27 planet candidate systems host multiple planet candidates. Using the new stellar parameters, we refit the K2 and TESS light curves to calculate updated planet properties. In general, our updated stellar properties are more precise than those previously reported and our updated planet properties agree well with those in the literature. Lastly, we briefly examine the relationship between stellar mass, stellar metallicity, and planetary system properties for targets in our sample and for previously characterized planet-hosting low-mass stars. We provide our spectra, stellar parameters, and new planetary fits to the community, expanding the sample available with which to investigate correlations between stellar and planetary properties for low-mass stars.

show abstract

Section: Updated Planet Radiimentioning

confidence: 99%

Metallicities and Refined Stellar Parameters for 52 Cool Dwarfs with Transiting Planets and Planet Candidates

Gore,

Giacalone,

Dressing

et al. 2024

ApJS

View full text Add to dashboard Cite

show abstract

“…However, multi-planet systems with a comparatively longer period planet are rarer still, restricting our ability to constrain position and width of the valley to learn about planet formation and evolution. To test predictive models, the composition The LHS 1903 planetary system of planets either side of the gap must be ascertained via precise radius and mass measurements [19][20][21][22][23]. For most multi-planet systems that contain small bodies on both sides of the valley no refined mass measurements are available restricting model assessment.…”

mentioning

confidence: 99%

LHS 1903 provides evidence for gas-depleted formation of planets around M-dwarfs

Wilson,

Simpson,

Cameron

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

Many important advances in planet formation theory have come from the discovery of unexpected planets. The thousands of discovered exoplanets have unveiled demographic trends, such as the bimodality of planetary radius distribution known as the radius valley. Modelling these trends can probe underlying processes, e.g. the formation environment and atmospheric evolution. Here, we report the discovery and characterisation of a four-planet system around the kinematically thick-disk M-dwarf LHS 1903 with orbital periods of 2.16, 6.23, 12.57, and 29.32 days that becomes the only known M-dwarf hosting four small, well-characterised planets spanning the radius valley. We utilise high-precision transit photometry from the Transiting Exoplanet Survey Satellite (TESS) and the CHaracterising ExOPlanets Satellite (CHEOPS) to measure the radii of LHS 1903 b, c, d, and e (1.382+/-0.046, 2.046^+0.078_-0.074, 2.500^+0.078_-0.077, and 1.732^+0.059_-0.058 R_oplus). Combined with HARPS-N radial velocity data, we determine the planetary bulk densities (1.24^+0.21_-0.19, 0.53^+0.11_-0.09, 0.38^+0.09_-0.08, and 1.11^+0.33_-0.31 rho_oplus). Our compositional analysis finds that planet b is rocky, planets c and d have extended atmospheres, and LHS 1903 e does not have a gaseous envelope. Our discovery that planet e, the longest-period well-characterised terrestrial M-dwarf planet, lacks an extended atmosphere causes tension with thermally-driven mass loss radius valley predictions, but supports a gas-depleted formation explanation. The observed broken atmospheric-mass fraction trend is at odds with current formation theory, but provides further evidence for a gas-depleted formation environment for terrestrial M-dwarf planets.

show abstract

The CARMENES search for exoplanets around M dwarfs

Ribas

Reiners

Zechmeister

et al. 2023

A&A

Self Cite

View full text Add to dashboard Cite

Context. The CARMENES instrument, installed at the 3.5 m telescope of the Calar Alto Observatory in Almería, Spain, was conceived to deliver high-accuracy radial velocity (RV) measurements with long-term stability to search for temperate rocky planets around a sample of nearby cool stars. Moreover, the broad wavelength coverage was designed to provide a range of stellar activity indicators to assess the nature of potential RV signals and to provide valuable spectral information to help characterise the stellar targets. Aims. We describe the CARMENES guaranteed time observations (GTO), spanning from 2016 to 2020, during which 19 633 spectra for a sample of 362 targets were collected. We present the CARMENES Data Release 1 (DR1), which makes public all observations obtained during the GTO of the CARMENES survey. Methods. The CARMENES survey target selection was aimed at minimising biases, and about 70% of all known M dwarfs within 10 pc and accessible from Calar Alto were included. The data were pipeline-processed, and high-level data products, including 18 642 precise RVs for 345 targets, were derived. Time series data of spectroscopic activity indicators were also obtained. Results. We discuss the characteristics of the CARMENES data, the statistical properties of the stellar sample, and the spectroscopic measurements. We show examples of the use of CARMENES data and provide a contextual view of the exoplanet population revealed by the survey, including 33 new planets, 17 re-analysed planets, and 26 confirmed planets from transiting candidate follow-up. A subsample of 238 targets was used to derive updated planet occurrence rates, yielding an overall average of 1.44 ± 0.20 planets with 1 M⊕ < Mpl sin i < 1000 M⊕ and 1 day < Porb < 1000 days per star, and indicating that nearly every M dwarf hosts at least one planet. All the DR1 raw data, pipeline-processed data, and high-level data products are publicly available online. Conclusions. CARMENES data have proven very useful for identifying and measuring planetary companions. They are also suitable for a variety of additional applications, such as the determination of stellar fundamental and atmospheric properties, the characterisation of stellar activity, and the study of exoplanet atmospheres.

show abstract

TOI-1468: A system of two transiting planets, a super-Earth and a mini-Neptune, on opposite sides of the radius valley

Cited by 12 publications

References 145 publications

Metallicities and Refined Stellar Parameters for 52 Cool Dwarfs with Transiting Planets and Planet Candidates

Metallicities and Refined Stellar Parameters for 52 Cool Dwarfs with Transiting Planets and Planet Candidates

LHS 1903 provides evidence for gas-depleted formation of planets around M-dwarfs

The CARMENES search for exoplanets around M dwarfs

Contact Info

Product

Resources

About