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 Porb ~ 2.9 - 19 d, i.e., a compact planetary system with super-Earth (~3 M⊕) to Neptune-mass (~24 M⊕) 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.
@article{arxiv.1912.10792,
title = {A compact multi-planet system around a bright nearby star from the Dispersed Matter Planet Project},
author = {D. Staab and C. A. Haswell and J. R. Barnes and G. Anglada-Escudé and L. Fossati and J. P. J. Doherty and J. Cooper and J. S. Jenkins and M. R. Díaz and M. G. Soto},
journal= {arXiv preprint arXiv:1912.10792},
year = {2020}
}
Comments
Accepted for publication by Nature Astronomy on 12th November 2019 (Main article, Methods and Supplementary Information; 24 pages, 10 figures, 3 tables)