Abstract
TOI-1227 b is an 11 Myr old validated transiting planet in the middle of its contraction phase, with a current radius of 0.85 RJ. It orbits a low-mass pre-main sequence star (0.170 M⊙, 0.56 R⊙) every 27.4 days. The magnetic activity of its young host star induces radial velocity jitter and prevents good measurements of the planetary mass. We gathered additional transit observations of TOI-1227 b with space- and ground-based telescopes, and we detected highly significant transit-timing variations (TTVs). Their amplitude is about 40 minutes and their dominant timescale is longer than 3.7 years. Their most probable origin is dynamical interactions with additional planets in the system. We modeled the TTVs with inner and outer perturbers near first and second order resonances; several orbital configurations provide an acceptable fit. More data are needed to determine the actual orbital configuration and eventually measure the planetary masses. These TTVs and an updated transit chromaticity analysis reinforce the evidence that TOI-1227 b is a planet.
Original language | English |
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Article number | A96 |
Number of pages | 12 |
Journal | Astronomy and Astrophysics |
Volume | 683 |
DOIs | |
Publication status | Published - 12 Mar 2024 |
Bibliographical note
Acknowledgments:We are grateful to the ESO/La Silla staff for their continuous support of ExTrA and to the wintering staff at Concordia Station in Antarctica who look after ASTEP during the long austral winter night. We acknowledge funding from the European Research Council under the ERC Grant Agreement n. 337591-ExTrA. This paper includes data collected with the TESS mission, obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the TESS mission is provided by the NASA Explorer Program. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5_26555. We acknowledge the use of public TESS data from the pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Resources supporting this work were provided by the NASA High-End Computing (HEC) program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. This work makes use of observations from the Las Cumbres Observatory global telescope network. Simulations in this paper made use of the REBOUND code which can be downloaded freely at http://github.com/hannorein/rebound. We thank the Swiss National Science Foundation (SNSF) and the Geneva University for their continuous support to our planet search programs. This work has been carried out within the framework of the National Centre of Competence in Research PlanetS supported by the Swiss National Science Foundation under grants 51NF40_182901 and 51NF40_205606. The authors acknowledge the financial support of the SNSF. This paper is based on data collected by the SPECULOOS-South Observatory at the ESO Paranal Observatory in Chile. The ULiege’s contribution to SPECULOOS has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013; grant Agreement no. 336480/SPECULOOS), from the Balzan Prize and Francqui Foundations, from the Belgian Scientific Research Foundation (F.R.S.-FNRS; grant no. T.0109.20), from the University of Liège, and from the ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. The Cambridge contribution is supported by a grant from the Simons Foundation (PI: Queloz, grant number 327127). The Birmingham contribution research is in part funded by the European Union’s Horizon 2020 research and innovation programme (grant’s agreement no. 803193/BEBOP), from the MERAC foundation, and from the Science and Technology Facilities Council (STFC; grant no. ST/S00193X/1, and ST/W000385/1). This is also based on data collected by the TRAPPIST-South telescope at the ESO La Silla Observatory. TRAPPIST is funded by the Belgian Fund for Scientific Research (Fond National de la Recherche Scientifique, FNRS) under the grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Fundation (SNF). E.J. is a Senior Research Scientist at FNRS. This paper uses data obtained with the ASTEP telescope, at Concordia Station in Antarctica. ASTEP benefited from the support of the French and Italian polar agencies IPEV and PNRA in the framework of the Concordia station program, from OCA, INSU, Idex UCAJEDI (ANR- 15-IDEX-01) and ESA through the Science Faculty of the European Space Research and Technology Centre (ESTEC). The Birmingham contribution to ASTEP is supported by the European Union’s Horizon 2020 research and innovation programme (grant’s agreement no. 803193/BEBOP), and from the Science and Technology Facilities Council (STFC; grant no. ST/S00193X/1, and ST/W002582/1). This research has made use of the Spanish Virtual Observatory (https://svo. cab.inta-csic.es) project funded by MCIN/AEI/10.13039/501100011033/ through grant PID2020-112949GB-I00. This work was supported by the "Programme National de Physique Stellaire" (PNPS) and “Programme National de Planétology” of CNRS/INSU co-funded by CEA and CNES. M.L. acknowledges support of the Swiss National Science Foundation under grant number PCEFP2_194576. J.V. acknowledges support from the Swiss National Science Foundation (SNSF) under grant PZ00P2_208945.
Keywords
- techniques: photometric
- stars: individual: TOI-1227
- stars: low-mass
- planetary systems
- stars: pre-main sequence