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Published September 2024 | Version Published
Journal Article Open

An Earth-sized Planet on the Verge of Tidal Disruption

Creators

  • 1. ROR icon University of Hawaii at Manoa
  • 2. ROR icon California Institute of Technology
  • 3. ROR icon Jet Propulsion Lab
  • 4. ROR icon Instituto de Astrofísica de Canarias
  • 5. ROR icon University of California, Berkeley
  • 6. ROR icon University of Southern Queensland
  • 7. ROR icon NASA Exoplanet Science Institute
  • 8. ROR icon University of Chicago
  • 9. ROR icon University of Toronto
  • 10. ROR icon University of California, Los Angeles
  • 11. ROR icon University of Notre Dame
  • 12. ROR icon University of Sydney
  • 13. ROR icon University of Amsterdam
  • 14. ROR icon Osaka University
  • 15. ROR icon Gemini North Observatory
  • 16. ROR icon Princeton University
  • 17. ROR icon University of California, Irvine
  • 18. ROR icon Massachusetts Institute of Technology
  • 19. ROR icon University of Kansas
  • 20. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 21. ROR icon University of California, Santa Cruz
  • 22. ROR icon W.M. Keck Observatory
  • 23. Schmidt Sciences
  • 24. ROR icon Macquarie University
  • 25. ROR icon Tsinghua University
  • 26. ROR icon Pennsylvania State University
  • 27. ROR icon Centro de Astrobiología
  • 28. ROR icon Institute of Space Sciences
  • 29. ROR icon Institut d'Estudis Espacials de Catalunya
  • 30. ROR icon University of La Laguna
  • 31. ROR icon University of Göttingen
  • 32. ROR icon Universität Hamburg
  • 33. ROR icon Complutense University of Madrid
  • 34. ROR icon Western Connecticut State University
  • 35. ROR icon Search for Extraterrestrial Intelligence
  • 36. ROR icon University of Liège
  • 37. ROR icon University of Tokyo
  • 38. Kotizarovci Observatory
  • 39. ROR icon Ames Research Center

Abstract

TOI-6255 b (GJ 4256) is an Earth-sized planet (1.079 ± 0.065 R⊕) with an orbital period of only 5.7 hr. With the newly commissioned Keck Planet Finder and CARMENES spectrographs, we determine the planet's mass to be 1.44 ± 0.14 M⊕. The planet is just outside the Roche limit, with Porb/PRoche = 1.13 ± 0.10. The strong tidal force likely deforms the planet into a triaxial ellipsoid with a long axis that is ∼10% longer than the short axis. Assuming a reduced stellar tidal quality factor Q⋆′≈10⁷, we predict that tidal orbital decay will cause TOI-6255 to reach the Roche limit in roughly 400 Myr. Such tidal disruptions may produce the possible signatures of planet engulfment that have been seen on stars with anomalously high refractory elemental abundances compared to their conatal binary companions. TOI-6255 b is also a favorable target for searching for star–planet magnetic interactions, which might cause interior melting and hasten orbital decay. TOI-6255 b is a top target (with an Emission Spectroscopy Metric of about 24) for phase-curve observations with the James Webb Space Telescope.

Copyright and License

© 2024. The Author(s). Published by the American Astronomical Society.

Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Acknowledgement

We thank Henrique Reggiani for an independent investigation of the stellar spectrum. We thank Doug Lin, Luke Bouma, Eugene Chiang, Darryl Seligman, Saul Rappaport, Jennifer van Saders, Ji Wang, and Li Zeng for insightful discussions. We also thank Connie Rockosi for their contribution to the successful construction of the KPF.

Support for this work was provided by NASA through the NASA Hubble Fellowship grant HST-HF2-51503.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555.

A NASA Key Strategic Mission Support titled "Pinning Down Masses of JWST Ultra-short-period Planets with KPF" (PI: F. Dai) provided the telescope access and funding for the completion of this project.

This work was supported by a NASA Keck PI Data Award, administered by the NASA Exoplanet Science Institute. The data presented herein were obtained at the W. M. Keck Observatory from telescope time allocated to the National Aeronautics and Space Administration through the agency's scientific partnership with the California Institute of Technology and the University of California. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.

We acknowledge the use of public TESS data from 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 paper made use of data collected by the TESS mission that are publicly available from the Mikulski Archive for Space Telescopes (MAST) operated by the Space Telescope Science Institute (STScI).

Funding for the TESS mission is provided by NASA's Science Mission Directorate. K.A.C. and C.N.W. acknowledge support from the TESS mission via subaward s3449 from MIT.

This research has made use of the Exoplanet Follow-up Observation Program (ExoFOP) website (NExScI 2022), which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program.

This work makes use of observations from the LCOGT network. Part of the LCOGT telescope time was granted by NOIRLab through the Mid-Scale Innovations Program (MSIP). MSIP is funded by NSF.

This work is partly supported by JSPS KAKENHI grant No. JPJP24H00017 and JSPS Bilateral Program Number JPJSBP120249910. This article is based on observations made with the MuSCAT2 instrument, developed by ABC, at Telescopio Carlos Sánchez, operated on the island of Tenerife by the IAC in the Spanish Observatorio del Teide. This paper is based on observations made with the MuSCAT3 instrument, developed by the Astrobiology Center and under financial support from JSPS KAKENHI (JP18H05439) and JST PRESTO (JPMJPR1775), at Faulkes Telescope North on Maui, HI, operated by the Las Cumbres Observatory.

This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004).

We acknowledge financial support from the Agencia Estatal de Investigación of the Ministerio de Ciencia e Innovación MCIN/AEI/10.13039/501100011033 and the ERDF "A way of making Europe" through project PID2021-125627OB-C32, and from the Centre of Excellence "Severo Ochoa" award to the Instituto de Astrofisica de Canarias.

D.H. acknowledges support from the Alfred P. Sloan Foundation, the National Aeronautics and Space Administration (80NSSC21K0652), and the Australian Research Council (FT200100871).

D.R.C. and C.A.C. acknowledge support from NASA 18-2XRP18_2-0007.

Facilities

Keck:I (KPF) - KECK I Telescope, 3.5m Calar Alto - , TESS - , LCOGT - Las Cumbres Observatory Global Telescope, MuSCAT2 - , MuSCAT3 - , WASP - , Palomar - .

Software References

AstroImage (Collins et al. 2017), Isoclassify (Huber et al. 2017), isochrones (Morton 2015), MIST (Choi et al. 2016), SpecMatch-Syn (Petigura 2015), Batman (Kreidberg 2015), emcee (Foreman-Mackey et al. 2013).

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Additional details

Related works

Is new version of
Discussion Paper: arXiv:2407.21167 (arXiv)

Funding

National Aeronautics and Space Administration
NASA Hubble Fellowship HST-HF2-51503.001-A
Space Telescope Science Institute
National Aeronautics and Space Administration
NAS5-26555
W. M. Keck Foundation
Massachusetts Institute of Technology
s3449
Japan Society for the Promotion of Science
JPJP24H00017
Japan Society for the Promotion of Science
JPJSBP120249910
Japan Society for the Promotion of Science
JP18H05439
Japan Science and Technology Agency
JPMJPR1775
Jet Propulsion Laboratory
National Aeronautics and Space Administration
80NM0018D0004
Agencia Estatal de Investigación
10.13039/501100011033
Ministerio de Ciencia, Innovación y Universidades
Agencia Estatal de Investigación
PID2021-125627OB-C32
Instituto de Astrofísica de Canarias
Alfred P. Sloan Foundation
National Aeronautics and Space Administration
80NSSC21K0652
Australian Research Council
FT200100871
National Aeronautics and Space Administration
18-2XRP18_2-0007
Heising-Simons Foundation
51 Pegasi b Postdoctoral Fellowship -
National Science Foundation
Graduate Research Fellowship -
National Aeronautics and Space Administration
NASA FINESST Fellowship -

Dates

Accepted
2024-06-17
Accepted
Available
2024-08-01
Published

Caltech Custom Metadata

Caltech groups
Astronomy Department, Infrared Processing and Analysis Center (IPAC), Division of Geological and Planetary Sciences (GPS), Division of Physics, Mathematics and Astronomy (PMA)
Publication Status
Published