Revisiting ρ1 Cancri e: a new mass determination of the transiting super-earth

Endl, Michael and Robertson, Paul and Cochran, William D. and MacQueen, Phillip J. and Brugamyer, Erik J. and Caldwell, Caroline and Wittenmyer, Robert A. and Barnes, Stuart I. and Gullikson, Kevin (2012) Revisiting ρ1 Cancri e: a new mass determination of the transiting super-earth. The Astrophysical Journal, 759 (1). pp. 1-7. ISSN 0004-637X

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We present a mass determination for the transiting super-Earth ρ1 Cancri e based on nearly 700 precise radial velocity (RV) measurements. This extensive RV data set consists of data collected by the McDonald Observatory planet search and published data from Lick and Keck observatories. We obtained 212 RV measurements with the Tull Coudé Spectrograph at the Harlan J. Smith 2.7m Telescope and combined them with a new Doppler reduction of the 131 spectra that we have taken in 2003-2004 with the High-Resolution Spectrograph (HRS) at the Hobby-Eberly Telescope for the original discovery of ρ1 Cancri e. Using this large data set we obtain a five-planet Keplerian orbital solution for the system and measure an RV semi-amplitude of K = 6.29 ± 0.21ms-1 for ρ1 Cnc e and determine a mass of 8.37 ±0.38 M⊕. The uncertainty in mass is thus less than 5%. This planet was previously found to transit its parent star, which allowed them to estimate its radius. Combined with the latest radius estimate from Gillon et al., we obtain a mean density of ρ = 4.50 ± 0.20gcm-3. The location of ρ1 Cnc e in the mass-radius diagram suggests that the planet contains a significant amount of volatiles, possibly a water-rich envelope surrounding a rocky core.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Access to Published version allowed due to publisher copyright policy.
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 19 May 2017 04:31
Last Modified: 07 Mar 2018 00:54
Uncontrolled Keywords: planetary systems; techniques - radial velocities;
Fields of Research (2008): 02 Physical Sciences > 0201 Astronomical and Space Sciences > 020110 Stellar Astronomy and Planetary Systems
Fields of Research (2020): 51 PHYSICAL SCIENCES > 5101 Astronomical sciences > 510109 Stellar astronomy and planetary systems
Socio-Economic Objectives (2008): E Expanding Knowledge > 97 Expanding Knowledge > 970102 Expanding Knowledge in the Physical Sciences
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