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Title: MOST DETECTS TRANSITS OF HD 97658b, A WARM, LIKELY VOLATILE-RICH SUPER-EARTH

Through photometric monitoring of the extended transit window of HD 97658b with the MOST space telescope, we have found that this exoplanet transits with an ephemeris consistent with that predicted from radial velocity measurements. The mid-transit times are 5.6{sigma} earlier than those of the unverified transit-like signals reported in 2011, and we find no connection between the two sets of events. The transit depth together with our determined stellar radius (R{sub *} = 0.703{sub -0.034}{sup +0.039} R{sub Sun }) indicates a 2.34{sup +0.18}{sub -0.15} R{sub Circled-Plus} super-Earth. When combined with the radial velocity determined mass of 7.86 {+-} 0.73 M{sub Circled-Plus }, our radius measure allows us to derive a planet density of 3.44{sup +0.91}{sub -0.82} g cm{sup -3}. Models suggest that a planet with our measured density has a rocky core that is enveloped in an atmosphere composed of lighter elements. The star of the HD 97658 system is the second brightest known to host a transiting super-Earth, facilitating follow-up studies of this not easily daunted, warm and likely volatile-rich exoplanet.
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ; ;  [6] ;  [7] ;  [8] ;  [9] ;  [10]
  1. Las Cumbres Observatory Global Telescope Network, 6740 Cortona Dr. suite 102, Goleta, CA 93117 (United States)
  2. Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T1Z1 (Canada)
  3. Department of Mathematics, Physics and Geology, Cape Breton University, 1250 Grand Lake Road, Sydney, NS B1P 6L2 (Canada)
  4. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
  5. Department of Astronomy and Physics, St. Mary's University, Halifax, NS B3H 3C3 (Canada)
  6. Universitaet Wien, Institut fuer Astronomie, Tuerkenschanzstrasse 17, A-1180 Wien (Austria)
  7. Dept de physique, Univ de Montreal C.P. 6128, Succ. Centre-Ville, Montreal, QC H3C 3J7 (Canada)
  8. SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States)
  9. Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)
  10. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
Publication Date:
OSTI Identifier:
22118666
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 772; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; BRIGHTNESS; DENSITY; MASS; PHOTOMETRY; PLANETARY ATMOSPHERES; PLANETS; RADIAL VELOCITY; SPACE; STARS; TELESCOPES