TWO PLANETARY COMPANIONS AROUND THE K7 DWARF GJ 221: A HOT SUPER-EARTH AND A CANDIDATE IN THE SUB-SATURN DESERT RANGE
- Department of Astronomy, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile)
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015-1305 (United States)
- The Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
- Institut fuer Astrophysik, Universitaet Goettingen, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany)
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{sub Circled-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 (6.5 M{sub Circled-Plus }) in a hot orbit (3.87 day period, GJ 221c). Spectroscopic and photometric calibrations suggest that GJ 221 is slightly depleted ([Fe/H] {approx} -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.
- OSTI ID:
- 22140206
- Journal Information:
- Astrophysical Journal, Vol. 771, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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