A PLANETARY SYSTEM AROUND THE NEARBY M DWARF GJ 667C WITH AT LEAST ONE SUPER-EARTH IN ITS HABITABLE ZONE

Journal Article · Sun May 20 00:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/751/1/L16· OSTI ID:22047806

Anglada-Escude, Guillem; Butler, R Paul ^[1]; Arriagada, Pamela; Minniti, Dante ^[2]; Vogt, Steven S; Rivera, Eugenio J ^[3]; Crane, Jeffrey D; Shectman, Stephen A; Thompson, Ian B ^[4]; Haghighipour, Nader ^[5]; Carter, Brad D ^[6]; Tinney, C G; Wittenmyer, Robert A; Bailey, Jeremy A ^[7]; O'Toole, Simon J ^[8]; Jones, Hugh R. A. ^[9]

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1. Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Rd. NW, Washington, DC 20015 (United States)
2. Department of Astronomy, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile)
3. UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)
4. Carnegie Observatories, 813 Santa Barbara St., Pasadena, CA 91101-1292 (United States)
5. Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Monoa, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
6. Faculty of Sciences, University of Southern Queensland, Toowoomba 4350 (Australia)
7. Department of Astrophysics, School of Physics, University of New South Wales, Sydney 2052 (Australia)
8. Australian Astronomical Observatory, P.O. Box 296, Epping 1710 (Australia)
9. Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, Herts, AL10 9AB (United Kingdom)

We re-analyze 4 years of HARPS spectra of the nearby M1.5 dwarf GJ 667C available through the European Southern Observatory public archive. The new radial velocity (RV) measurements were obtained using a new data analysis technique that derives the Doppler measurement and other instrumental effects using a least-squares approach. Combining these new 143 measurements with 41 additional RVs from the Magellan/Planet Finder Spectrograph and Keck/High Resolution Echelle Spectrometer spectrometers reveals three additional signals beyond the previously reported 7.2 day candidate, with periods of 28 days, 75 days, and a secular trend consistent with the presence of a gas giant (period {approx}10 years). The 28 day signal implies a planet candidate with a minimum mass of 4.5 M{sub Circled-Plus} orbiting well within the canonical definition of the star's liquid water habitable zone (HZ), that is, the region around the star at which an Earth-like planet could sustain liquid water on its surface. Still, the ultimate water supporting capability of this candidate depends on properties that are unknown such as its albedo, atmospheric composition, and interior dynamics. The 75 day signal is less certain, being significantly affected by aliasing interactions among a potential 91 day signal, and the likely rotation period of the star at 105 days detected in two activity indices. GJ 667C is the common proper motion companion to the GJ 667AB binary, which is metal-poor compared to the Sun. The presence of a super-Earth in the HZ of a metal-poor M dwarf in a triple star system supports the evidence that such worlds should be ubiquitous in the Galaxy.

• OSTI ID: 22047806
• Journal Information: Astrophysical Journal Letters, Vol. 751, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ALBEDO
ASTRONOMY
ASTROPHYSICS
DATA ANALYSIS
DWARF STARS
GALAXIES
LEAST SQUARE FIT
LIQUIDS
MASS
METALS
PLANETS
PROPER MOTION
RADIAL VELOCITY
RESOLUTION
ROTATION
WATER