Nature Astronomy ( IF 11.518 ) Pub Date : 2019-12-23 , DOI: 10.1038/s41550-019-0974-x 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
To put the Solar System’s terrestrial planets in context, the detection and characterization of low-mass exoplanets is important but challenging. The Dispersed Matter Planet Project targets stars with anomalously low Ca ii H and K chromospheric emission, indicative of circumstellar absorbing gas. Here we report high-precision, high-cadence radial-velocity measurements of the F8V star DMPP-1 (HD 38677). These were motivated by depressed Ca ii H and K line cores indicative of short-period, ablating planets producing circumstellar gas. We find a compact planetary system with orbital periods of about 2.9–19 days, comprising three super-Earth-mass planets (about 3–10 M⊕) and one Neptune-mass planet (about 24 M⊕). The irradiated super-Earths may be remnant cores of giant planets after mass loss while crossing the Neptune desert. A priori inferences about the presence of short-period planets enabled the efficient discovery of the DMPP-1 planets. We anticipate informative follow-up characterization studies.