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arXiv · 1912.10792

A compact multi-planet system around a bright nearby star from the Dispersed Matter Planet Project

D. Staab·C. A. Haswell·J. R. Barnes·G. Anglada-Escudé·L. Fossati·J. P. J. Doherty·J. Cooper·J. S. Jenkins·M. R. Díaz·M. G. Soto
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Abstract

The Dispersed Matter Planet Project targets stars with anomalously low Ca II H&K chromospheric emission. High precision, high cadence radial velocity measurements of the F8V star HD 38677 / DMPP-1 reveal four short period planets. DMPP-1 has log(R'HK) = -5.16 which probably indicates the presence of circumstellar absorbing gas arising from an ablating hot planet. The planets have P$_{\rm orb}$ ~ 2.9 - 19 d, i.e., a compact planetary system with super-Earth (~3 M$_\oplus$) to Neptune-mass (~24 M$_\oplus$) planets. These irradiated planets may be chthonian: remnant cores of giant planets after mass-loss while crossing the Neptune desert. Modelling the possible long-term activity indicators while searching for Keplerian signals modifies the recovered planetary signals. A priori inferences about the presence of short period planets allowed the efficient discovery of the DMPP-1 planets. They have great potential for novel and informative follow-up characterisation studies.

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D. Staab, C. A. Haswell, J. R. Barnes, G. Anglada-Escudé, L. Fossati, J. P. J. Doherty, J. Cooper, J. S. Jenkins, M. R. Díaz, M. G. Soto. 2019-12-23. A compact multi-planet system around a bright nearby star from the Dispersed Matter Planet Project. https://doi.org/10.1038/s41550-019-0974-x

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