HD 97658 and its super-Earth

V. Van Grootel, M. Gillon, D. Valencia, N. Madhusudhan, D. Dragomir, A. R. Howe, A. S. Burrows

Research output: Contribution to journalConference article

Abstract

Super-Earths transiting nearby bright stars are key objects that simultaneously allow for accurate measurements of both their mass and radius, providing essential constraints on their internal composition. We present the confirmation, based on Spitzer observations, that the super-Earth HD 97658 b transits its host star. HD 97658 is a low-mass (M = 0.77 ± 0.05 M) K1 dwarf, as determined from the Hipparcos parallax and stellar evolution modeling. To constrain the planet parameters, we carry out Bayesian global analyses of Keck-HIRES radial velocities, and MOST and Spitzer photometry. HD 97658 b is a massive (MP = 7.55-0.79+0.83 M) and large (RP = 2.247-0.095+0.098 R at 4.5 μm super-Earth. We investigate the possible internal compositions for HD 97658 b. Our results indicate a large rocky component, by at least 60% by mass, and very little H-He components, at most 2% by mass. We also discuss how future asteroseismic observations can improve the knowledge of the HD 97658 system, in particular by constraining its age.

Original languageEnglish (US)
Article number02006
JournalEPJ Web of Conferences
Volume101
DOIs
StatePublished - Sep 23 2015
EventCoRoT Symposium 3, Kepler KASC-7 Joint Meeting on Space Photometry Revolution - Toulouse, France
Duration: Jul 6 2014Jul 11 2014

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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    Van Grootel, V., Gillon, M., Valencia, D., Madhusudhan, N., Dragomir, D., Howe, A. R., & Burrows, A. S. (2015). HD 97658 and its super-Earth. EPJ Web of Conferences, 101, [02006]. https://doi.org/10.1051/epjconf/201510102006