The Astronomical Journal (Jan 2024)
Investigating the Atmospheric Mass Loss of the Kepler-105 Planets Straddling the Radius Gap
- Aaron Householder,
- Lauren M. Weiss,
- James E. Owen,
- Howard Isaacson,
- Andrew W. Howard,
- Daniel Fabrycky,
- Leslie A. Rogers,
- Hilke E. Schlichting,
- Benjamin J. Fulton,
- Erik A. Petigura,
- Steven Giacalone,
- Joseph M. Akana Murphy,
- Corey Beard,
- Ashley Chontos,
- Fei Dai,
- Judah Van Zandt,
- Jack Lubin,
- Malena Rice,
- Alex S. Polanski,
- Paul Dalba,
- Sarah Blunt,
- Emma V. Turtelboom,
- Ryan Rubenzahl,
- Casey Brinkman
Affiliations
- Aaron Householder
- ORCiD
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, MA 02139, USA ; [email protected]; Department of Astronomy, Yale University , 52 Hillhouse, New Haven, CT 06511, USA
- Lauren M. Weiss
- ORCiD
- Department of Physics and Astronomy, University of Notre Dame , Notre Dame, IN 46556, USA
- James E. Owen
- ORCiD
- Astrophysics Group, Department of Physics, Imperial College London , Prince Consort Road, London SW7 2AZ, UK
- Howard Isaacson
- ORCiD
- Department of Astronomy, University of California Berkeley , Berkeley, CA 94720, USA; Centre for Astrophysics, University of Southern Queensland , Toowoomba, QLD, Australia
- Andrew W. Howard
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Daniel Fabrycky
- ORCiD
- Dept. of Astronomy & Astrophysics, University of Chicago , 5640 S. Ellis Avenue, Chicago, IL 60637, USA
- Leslie A. Rogers
- ORCiD
- Department of Astronomy and Astrophysics, University of Chicago , Chicago, IL 60637, USA
- Hilke E. Schlichting
- ORCiD
- Department of Earth, Planetary, and Space Sciences, The University of California , Los Angeles, 595 Charles E. Young Drive East, Los Angeles, CA 90095, USA
- Benjamin J. Fulton
- ORCiD
- Cahill Center for Astronomy & Astrophysics, California Institute of Technology , Pasadena, CA 91125, USA; IPAC-NASA Exoplanet Science Institute , Pasadena, CA 91125, USA
- Erik A. Petigura
- ORCiD
- Department of Physics & Astronomy, University of California Los Angeles , Los Angeles, CA 90095, USA
- Steven Giacalone
- ORCiD
- Department of Astronomy, University of California Berkeley , Berkeley, CA 94720, USA; Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Joseph M. Akana Murphy
- ORCiD
- Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USA
- Corey Beard
- ORCiD
- Department of Physics & Astronomy, The University of California , Irvine, Irvine, CA 92697, USA
- Ashley Chontos
- ORCiD
- Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08540, USA; Institute for Astronomy, University of Hawaii , 2680 Woodlawn Drive, Honolulu, HI 96822 USA
- Fei Dai
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA; Division of Geological and Planetary Sciences , 1200 E California Boulevard, Pasadena, CA, 91125, USA
- Judah Van Zandt
- ORCiD
- Department of Physics & Astronomy, University of California Los Angeles , Los Angeles, CA 90095, USA
- Jack Lubin
- ORCiD
- Department of Physics & Astronomy, University of California Irvine , Irvine, CA 92697, USA
- Malena Rice
- ORCiD
- Department of Astronomy, Yale University , 52 Hillhouse, New Haven, CT 06511, USA
- Alex S. Polanski
- ORCiD
- Department of Physics and Astronomy, University of Kansas , Lawrence, KS 66045, USA
- Paul Dalba
- ORCiD
- Department of Earth & Planetary Sciences, University of California Riverside , 900 University Avenue, Riverside, CA 92521, USA
- Sarah Blunt
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Emma V. Turtelboom
- ORCiD
- Department of Astronomy, 501 Campbell Hall, University of California , Berkeley, CA 94720, USA
- Ryan Rubenzahl
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Casey Brinkman
- ORCiD
- Institute for Astronomy, University of Hawaii , 2680 Woodlawn Drive, Honolulu, HI 96822 USA
- DOI
- https://doi.org/10.3847/1538-3881/ad19c6
- Journal volume & issue
-
Vol. 167,
no. 2
p. 84
Abstract
An intriguing pattern among exoplanets is the lack of detected planets between approximately 1.5 R _⊕ and 2.0 R _⊕ . One proposed explanation for this “radius gap” is the photoevaporation of planetary atmospheres, a theory that can be tested by studying individual planetary systems. Kepler-105 is an ideal system for such testing due to the ordering and sizes of its planets. Kepler-105 is a Sun-like star that hosts two planets straddling the radius gap in a rare architecture with the larger planet closer to the host star ( R _b = 2.53 ± 0.07 R _⊕ , P _b = 5.41 days, R _c = 1.44 ± 0.04 R _⊕ , P _c = 7.13 days). If photoevaporation sculpted the atmospheres of these planets, then Kepler-105b would need to be much more massive than Kepler-105c to retain its atmosphere, given its closer proximity to the host star. To test this hypothesis, we simultaneously analyzed radial velocities and transit-timing variations of the Kepler-105 system, measuring disparate masses of M _b = 10.8 ± 2.3 M _⊕ ( ρ _b = 3.68 ± 0.84 g cm ^−3 ) and M _c = 5.6 ± 1.2 M _⊕ ( ρ _c = 10.4 ± 2.39 g cm ^−3 ). Based on these masses, the difference in gas envelope content of the Kepler-105 planets could be entirely due to photoevaporation (in 76% of scenarios), although other mechanisms like core-powered mass loss could have played a role for some planet albedos.
Keywords
- Exoplanet atmospheres
- Exoplanet formation
- Exoplanet evolution
- Radial velocity
- Transit timing variation method
- Exoplanets
