TWO PLANETARY COMPANIONS AROUND THE K7 DWARF GJ 221: A HOT SUPER-EARTH AND A CANDIDATE IN THE SUB-SATURN DESERT RANGE

Arriagada, P; Anglada-Escude, G; Butler, RP; Crane, JD; Shectman, SA; Thompson, I; Wende, S; Minniti, D

Abstract

We report two low-mass companions orbiting the nearby K7 dwarf GJ 221 that have emerged from reanalyzing 4.4 yr of publicly available HARPS spectra complemented with 2 years of high-precision Doppler measurements with Magellan/PFS. The HARPS measurements alone contain the clear signal of a low-mass companion with a period of 125 days and a minimum mass of 53.2 M-circle plus (GJ 221b), falling in a mass range where very few planet candidates have been found (sub-Saturn desert). The addition of 17 PFS observations allows the confident detection of a second low-mass companion (6.5M(circle plus)) in a hot orbit (3.87 day period, GJ 221c). Spectroscopic and photometric calibrations suggest that GJ 221 is slightly depleted ([Fe/H]similar to-0.1) compared to the Sun, so the presence of two low-mass companions in the system confirms the trend that slightly reduced stellar metallicity does not prevent the formation of planets in the super-Earth to sub-Saturn mass regime.

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Título según WOS: TWO PLANETARY COMPANIONS AROUND THE K7 DWARF GJ 221: A HOT SUPER-EARTH AND A CANDIDATE IN THE SUB-SATURN DESERT RANGE
Título según SCOPUS: Two planetary companions around the K7 dwarf GJ 221: A hot super-earth and a candidate in the sub-saturn desert range
Título de la Revista: ASTROPHYSICAL JOURNAL
Volumen: 771
Número: 1
Editorial: IOP PUBLISHING LTD
Fecha de publicación: 2013
Idioma: English
URL: http://stacks.iop.org/0004-637X/771/i=1/a=42?key=crossref.cf87f89a10154a02a98b612f48f3dd6e
DOI:

10.1088/0004-637X/771/1/42

Notas: ISI, SCOPUS