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Abstract

Low-mass planets have an extraordinarily diverse range of bulk compositions, from primarily rocky worlds to those with deep gaseous atmospheres. As techniques for measuring the masses of exoplanets advance the field toward the regime of rocky planets, from ultrashort orbital periods to Venus-like distances, we identify the bounds on planet compositions, where sizes and incident fluxes inform bulk planet properties. In some cases, the precision of measurement of planet masses and sizes is approaching the theoretical uncertainties in planet models. An emerging picture explains aspects of the diversity of low-mass planets, although some problems remain: Do extreme low-density, low-mass planets challenge models of atmospheric mass loss? Are planet sizes strictly separated by bulk composition? Why do some stellar characterizations differ between observational techniques? With the () mission, low-mass exoplanets around the nearest stars will soon be discovered and characterized with unprecedented precision, permitting more detailed planetary modeling and atmospheric characterization of low-mass exoplanets than ever before.

  • ▪  Following the mission, studies of exoplanetary compositions have entered the terrestrial regime.
  • ▪  Low-mass planets have an extraordinary range of compositions, from Earth-like mixtures of rock and metal to mostly tenuous gas.
  • ▪  The mission will discover low-mass planets that can be studied in more detail than ever before.

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2019-05-30
2024-06-16
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Literature Cited

  1. Agol E, Deck K 2016. Transit timing to first order in eccentricity. Astrophys. J. 818:177
    [Google Scholar]
  2. Agol E, Steffen J, Sari R, Clarkson W 2005. On detecting terrestrial planets with timing of giant planet transits. Mon. Not. R. Astron. Soc. 359:567–79
    [Google Scholar]
  3. Almenara JM, Díaz RF, Dorn C, Bonfils X, Udry S 2018. Absolute densities in exoplanetary systems: photodynamical modelling of Kepler-138. Mon. Not. R. Astron. Soc 478:460–86
    [Google Scholar]
  4. Anglada-Escudé G, Amado PJ, Barnes J, Berdiñas ZM, Butler RP et al. 2016. A terrestrial planet candidate in a temperature orbit around Proxima Centauri. Nature 536:437–40
    [Google Scholar]
  5. Batalha NM, Borucki WJ, Bryson ST, Buchhave LA, Caldwell DA et al. 2011. Kepler's first rocky planet: Kepler-10b. Astrophys. J. 729:27
    [Google Scholar]
  6. Becker JC, Vanderburg A, Adams FC, Rappaport SA, Schwengeler HM 2015. WASP-47: a hot Jupiter system with two additional planets discovered by K2. Astrophys. J. Lett. 812:L18
    [Google Scholar]
  7. Bedell M, Bean JL, Meléndez J, Mills SM, Fabrycky DC et al. 2017. Kepler-11 is a solar twin: revising the masses and radii of benchmark planets via precise stellar characterization. Astrophys. J. 839:94
    [Google Scholar]
  8. Berger TA, Huber D, Gaidos E, van Saders JL 2018. Revised radii of Kepler stars and planets using Gaia Data Release 2. Astrophys. J. 866:99
    [Google Scholar]
  9. Bodenheimer P, Lissauer JJ 2014. Accretion and evolution of ∼2.5 M planets with voluminous H/He envelopes. Astrophys. J. 791:103
    [Google Scholar]
  10. Bond JC, O'Brien DP, Lauretta DS 2010. The compositional diversity of extrasolar terrestrial planets. I. In situ simulations. Astrophys. J. 715:1050–70
    [Google Scholar]
  11. Borucki WJ, Koch DG, Brown TM, Basri G, Batalha NM et al. 2010. Kepler-4b: a hot Neptune-like planet of a G0 star near main-sequence turnoff. Astrophys. J. Lett. 713:L126–30
    [Google Scholar]
  12. Borucki WJ, Koch DG, Dunham EW, Jenkins JM 1997. The Kepler Mission: a mission to determine the frequency of inner planets near the habitable zone for a wide range of stars. Planets Beyond the Solar System and the Next Generation of Space Missions D Soderblom153–173 Astron. Soc. Pac. Conf. Ser. 119 San Francisco, CA: Astron. Soc. Pac.
    [Google Scholar]
  13. Bourrier V, Ehrenreich D, Allart R, Wyttenbach A, Semaan T et al. 2017. Strong HI Lyman-α variations from an 11 Gyr-old host star: a planetary origin?. Astron. Astrophys. 602:A106
    [Google Scholar]
  14. Brown H 1950. On the compositions and structures of the planets.. Astrophys. J. 111:641
    [Google Scholar]
  15. Carter JA, Agol E, Chaplin WJ, Basu S, Bedding TR et al. 2012. Kepler-36: a pair of planets with neighboring orbits and dissimilar densities. Science 337:556–59
    [Google Scholar]
  16. Chatterjee S, Tan JC 2015. Vulcan planets: inside-out formation of the innermost super-Earths. Astrophys. J. Lett. 798:L32
    [Google Scholar]
  17. Chen J, Kipping D 2017. Probabilistic forecasting of the masses and radii of other worlds. Astrophys. J. 834:17
    [Google Scholar]
  18. Chiang E, Laughlin G 2013. The minimum-mass extrasolar nebula: in situ formation of close-in super-Earths. Mon. Not. R. Astron. Soc. 431:3444–55
    [Google Scholar]
  19. Ciardi DR, Fabrycky DC, Ford EB, Gautier TN III, Howell SB et al. 2013. On the relative sizes of planets within Kepler multiple-candidate systems. Astrophys. J. 763:41
    [Google Scholar]
  20. Cochran WD, Fabrycky DC, Torres G, Fressin F, Désert JM et al. 2011. Kepler-18b, c, and d: a system of three planets confirmed by transit timing variations, light curve validation, Warm-Spitzer photometry, and radial velocity measurements. Astrophys. J. Suppl. 197:7
    [Google Scholar]
  21. Crossfield IJM, Kreidberg L 2017. Trends in atmospheric properties of Neptune-size exoplanets. Astron. J. 154:261
    [Google Scholar]
  22. Cubillos P, Erkaev NV, Juvan I, Fossati L, Johnstone CP et al. 2017. An overabundance of low-density Neptune-like planets. Mon. Not. R. Astron. Soc. 466:1868–79
    [Google Scholar]
  23. Dai F, Winn JN, Gandolfi D, Wang SX, Teske JK et al. 2017. The discovery and mass measurement of a new ultra-short-period planet: K2-131b. Astron. J. 154:226
    [Google Scholar]
  24. Dorn C, Hinkel NR, Venturini J 2017. Bayesian analysis of interiors of HD 219134b, Kepler-10b, Kepler-93b, CoRoT-7b, 55 Cnc e, and HD 97658b using stellar abundance proxies. Astron. Astrophys. 597:A38
    [Google Scholar]
  25. Dressing CD, Charbonneau D, Dumusque X, Gettel S, Pepe F et al. 2015. The mass of Kepler-93b and the composition of terrestrial planets. Astrophys. J. 800:135
    [Google Scholar]
  26. Fabrycky DC, Lissauer JJ, Ragozzine D, Rowe JF, Steffen JH et al. 2014. Architecture of Kepler's multi-transiting systems. II. New investigations with twice as many candidates. Astrophys. J. 790:146
    [Google Scholar]
  27. Faria JP, Haywood RD, Brewer BJ, Figueira P, Oshagh M et al. 2016. Uncovering the planets and stellar activity of CoRoT-7 using only radial velocities. Astron. Astrophys. 588:A31
    [Google Scholar]
  28. Ford EB, Holman MJ 2007. Using transit timing observations to search for Trojans of transiting extrasolar planets. Astrophys. J. Lett. 664:L51–54
    [Google Scholar]
  29. Ford EB, Ragozzine D, Rowe JF, Steffen JH, Barclay T et al. 2012. Transit timing observations from Kepler. V. Transit timing variation candidates in the first sixteen months from polynomial models. Astrophys. J. 756:185
    [Google Scholar]
  30. Fortney JJ, Marley MS, Barnes JW 2007. Planetary radii across five orders of magnitude in mass and stellar insolation: application to transits. Astrophys. J. 659:1661–72
    [Google Scholar]
  31. Fulton BJ, Petigura EA 2018. The California-Kepler Survey VII. Precise planet radii leveraging Gaia DR2 reveal the stellar mass dependence of the planet radius gap. Astron. J. 156:264
    [Google Scholar]
  32. Fulton BJ, Petigura EA, Howard AW, Isaacson H, Marcy GW et al. 2017. The California-Kepler Survey. III. A gap in the radius distribution of small planets. Astron. J. 154:109
    [Google Scholar]
  33. Gaia Collab., Brown AGA, Vallenari A, Prusti T, de Bruijne JHJ et al. 2018. Gaia Data Release 2. Summary of the contents and survey properties. Astron. Astrophys. 616:A1
    [Google Scholar]
  34. Gomes da Silva J, Santos NC, Bonfils X, Delfosse X, Forveille T et al. 2012. Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program. II. Activity and radial velocity. Astron. Astrophys. 541:A9
    [Google Scholar]
  35. Grasset O, Schneider J, Sotin C 2009. A study of the accuracy of mass-radius relationships for silicate-rich and ice-rich planets up to 100 Earth masses. Astrophys. J. 693:722–33
    [Google Scholar]
  36. Greene TP, Line MR, Montero C, Fortney JJ, Lustig-Yaeger J, Luther K 2016. Characterizing transiting exoplanet atmospheres with JWST. Astrophys. J. 817:17
    [Google Scholar]
  37. Grimm SL, Demory BO, Gillon M, Dorn C, Agol E et al. 2018. The nature of the TRAPPIST-1 exoplanets. Astron. Astrophys. 613:A68
    [Google Scholar]
  38. Guenther EW, Barragán O, Dai F, Gandolfi D, Hirano T et al. 2017. K2-106, a system containing a metal-rich planet and a planet of lower density. Astron. Astrophys. 608:A93
    [Google Scholar]
  39. Hadden S, Lithwick Y 2014. Densities and eccentricities of 139 Kepler planets from transit time variations. Astrophys. J. 787:80
    [Google Scholar]
  40. Hadden S, Lithwick Y 2017. Kepler planet masses and eccentricities from TTV analysis. Astron. J. 154:5
    [Google Scholar]
  41. Holman MJ, Fabrycky DC, Ragozzine D, Ford EB, Steffen JH et al. 2010. Kepler-9: a system of multiple planets transiting a sun-like star, confirmed by timing variations. Science 330:51–54
    [Google Scholar]
  42. Holman MJ, Murray NW 2005. The use of transit timing to detect terrestrial-mass extrasolar planets. Science 307:1288–91
    [Google Scholar]
  43. Howard AW, Sanchis-Ojeda R, Marcy GW, Johnson JA, Winn JN et al. 2013. A rocky composition for an Earth-sized exoplanet. Nature 503:381–84
    [Google Scholar]
  44. Hsu DC, Ford EB, Ragozzine D, Morehead RC 2018. Improving the accuracy of planet occurrence rates from Kepler using approximate Bayesian computation. Astron. J. 155:205
    [Google Scholar]
  45. Huber D, Chaplin WJ, Christensen-Dalsgaard J, Gilliland RL, Kjeldsen H et al. 2013. Fundamental properties of Kepler planet-candidate host stars using asteroseismology. Astrophys. J. 767:127
    [Google Scholar]
  46. Hurley PM 1957. Test on the possible chondritic composition of the Earth's mantle and its abundance of uranium, thorium, and potassium. Geol. Soc. Am. Bull. 68:379–82
    [Google Scholar]
  47. Ikoma M, Hori Y 2012. In situ accretion of hydrogen-rich atmospheres on short-period super-Earths: implications for the Kepler-11 planets. Astrophys. J. 753:66
    [Google Scholar]
  48. Jackson AP, Davis TA, Wheatley PJ 2012. The coronal X-ray-age relation and its implications for the evaporation of exoplanets. Mon. Not. R. Astron. Soc. 422:2024–43
    [Google Scholar]
  49. Johnson JA, Petigura EA, Fulton BJ, Marcy GW, Howard AW et al. 2017. The California-Kepler Survey. II. Precise physical properties of 2025 Kepler planets and their host stars. Astron. J. 154:108
    [Google Scholar]
  50. Jontof-Hutter D, Ford EB, Rowe JF, Lissauer JJ, Fabrycky DC 2016a. The diversity of low-mass exoplanets characterized via transit timing. Proc. Int. Astron. Union 11:40–50
    [Google Scholar]
  51. Jontof-Hutter D, Ford EB, Rowe JF, Lissauer JJ, Fabrycky DC et al. 2016b. Secure mass measurements from transit timing: 10 Kepler exoplanets between 3 and 8 with diverse densities and incident fluxes. Astrophys. J. 820:39
    [Google Scholar]
  52. Jontof-Hutter D, Lissauer JJ, Rowe JF, Fabrycky DC 2014. Kepler-79’s low density planets. Astrophys. J. 785:15
    [Google Scholar]
  53. Jontof-Hutter D, Lissauer JJ, Rowe JF, Fabrycky DC 2015. The mass of the Mars-sized exoplanet Kepler-138 b from transit timing.. Nature 522:321–23
    [Google Scholar]
  54. Kipping DM 2010. Investigations of approximate expressions for the transit duration. Mon. Not. R. Astron. Soc. 407:301–13
    [Google Scholar]
  55. Kipping DM, Nesvorný D, Buchhave LA, Hartman J, Bakos , Schmitt AR 2014. The hunt for exomoons with Kepler (HEK). IV. A search for moons around eight M dwarfs. Astrophys. J. 784:28
    [Google Scholar]
  56. Knudson MD, Desjarlais MP, Lemke RW, Mattsson TR, French M et al. 2012. Probing the interiors of the ice giants: shock compression of water to 700 GPa and 3.8g/cm. Phys. Rev. Lett. 108:091102
    [Google Scholar]
  57. Kotani T, Tamura M, Suto H, Nishikawa J, Sato B et al. 2014. Infrared Doppler instrument (IRD) for the Subaru telescope to search for Earth-like planets around nearby M-dwarfs. SPIE Proceedings 9147 Ground-Based and Airborne Instrumentation for Astronomy V, Proceedings of SPIE AStronomical Telescopes + Instrumentation, Montreal, Quebec, Canada 14–23 Bellingham, WA: SPIE
    [Google Scholar]
  58. Kreidberg L, Bean JL, Désert JM, Benneke B, Deming D et al. 2014. Clouds in the atmosphere of the super-Earth exoplanet GJ1214b. Nature 505:69–72
    [Google Scholar]
  59. Lee EJ, Chiang E 2016. Breeding super-Earths and birthing super-puffs in transitional disks. Astrophys. J. 817:90
    [Google Scholar]
  60. Léger A, Rouan D, Schneider J, Barge P, Fridlund M et al. 2009. Transiting exoplanets from the CoRoT space mission. VIII. CoRoT-7b: the first super-Earth with measured radius. Astron. Astrophys. 506:287–302
    [Google Scholar]
  61. Ligi R, Creevey O, Mourard D, Crida A, Lagrange AM et al. 2016. Radii, masses, and ages of 18 bright stars using interferometry and new estimations of exoplanetary parameters. Astron. Astrophys. 586:A94
    [Google Scholar]
  62. Lissauer JJ, Fabrycky DC, Ford EB, Borucki WJ, Fressin F et al. 2011a. A closely packed system of low-mass, low-density planets transiting Kepler-11. Nature 470:53–58
    [Google Scholar]
  63. Lissauer JJ, Jontof-Hutter D, Rowe JF, Fabrycky DC, Lopez ED et al. 2013. All six planets known to orbit Kepler-11 have low densities. Astrophys. J. 770:131
    [Google Scholar]
  64. Lissauer JJ, Ragozzine D, Fabrycky DC, Steffen JH, Ford EB et al. 2011b. Architecture and dynamics of Kepler's candidate multiple transiting planet systems. Astrophys. J. Suppl. 197:8
    [Google Scholar]
  65. Lithwick Y, Xie J, Wu Y 2012. Extracting planet mass and eccentricity from TTV data. Astrophys. J. 761:122
    [Google Scholar]
  66. Lopez ED, Fortney JJ 2013. The role of core mass in controlling evaporation: the Kepler radius distribution and the Kepler-36 density dichotomy. Astrophys. J. 776:2
    [Google Scholar]
  67. Lopez ED, Fortney JJ 2014. Understanding the mass-radius relation for sub-Neptunes: radius as a proxy for composition. Astrophys. J. 792:1
    [Google Scholar]
  68. Lopez ED, Fortney JJ, Miller N 2012. How thermal evolution and mass-loss sculpt populations of super-Earths and sub-Neptunes: application to the Kepler-11 system and beyond. Astrophys. J. 761:59
    [Google Scholar]
  69. MacDonald MG, Ragozzine D, Fabrycky DC, Ford EB, Holman MJ et al. 2016. A dynamical analysis of the Kepler-80 system of five transiting planets. Astron. J. 152:105
    [Google Scholar]
  70. Mahadevan S, Ramsey LW, Terrien R, Halverson S, Roy A et al. 2014. The Habitable-zone Planet Finder: A status update on the development of a stabilized fiber-fed near-infrared spectrograph for the for the Hobby-Eberly telescope. SPIE Proceedings 9147 Ground-Based and Airborne Instrumentation for Astronomy V, Proceedings of SPIE AStronomical Telescopes + Instrumentation, Montreal, Quebec, Canada 1–10 Bellingham, WA: SPIE
    [Google Scholar]
  71. Marcy GW, Isaacson H, Howard AW, Rowe JF, Jenkins JM et al. 2014. Masses, radii, and orbits of small Kepler planets: the transition from gaseous to rocky planets. Astrophys. J. Suppl. 210:20
    [Google Scholar]
  72. Masuda K 2014. Very low density planets around Kepler-51 revealed with transit timing variations and an anomaly similar to a planet-planet eclipse event. Astrophys. J. 783:53
    [Google Scholar]
  73. Masuda K, Hirano T, Taruya A, Nagasawa M, Suto Y 2013. Characterization of the KOI-94 system with transit timing variation analysis: implication for the planet-planet eclipse. Astrophys. J. 778:185
    [Google Scholar]
  74. Mazeh T, Holczer T, Faigler S 2016. Dearth of short-period Neptunian exoplanets: a desert in period-mass and period-radius planes. Astron. Astrophys. 589:A75
    [Google Scholar]
  75. Miller-Ricci E, Seager S, Sasselov D 2009. The atmospheric signatures of super-Earths: how to distinguish between hydrogen-rich and hydrogen-poor atmospheres. Astrophys. J. 690:1056–67
    [Google Scholar]
  76. Mills SM, Fabrycky DC 2017. Mass, density, and formation constraints in the compact, sub-Earth Kepler-444 system including two Mars-mass planets. Astrophys. J. Lett. 838:L11
    [Google Scholar]
  77. Mills SM, Fabrycky DC, Migaszewski C, Ford EB, Petigura E, Isaacson H 2016. A resonant chain of four transiting, sub-Neptune planets. Nature 533:509–12
    [Google Scholar]
  78. Mills SM, Mazeh T 2017. The planetary mass-radius relation and its dependence on orbital period as measured by transit timing variations and radial velocities. Astrophys. J. Lett. 839:L8
    [Google Scholar]
  79. Morley CV, Kreidberg L, Rustamkulov Z, Robinson T, Fortney JJ 2017. Observing the atmospheres of known temperate Earth-sized planets with JWST. Astrophys. J. 850:121
    [Google Scholar]
  80. Morton TD, Bryson ST, Coughlin JL, Rowe JF, Ravichandran G et al. 2016. False positive probabilities for all Kepler objects of interest: 1284 newly validated planets and 428 likely false positives. Astrophys. J. 822:86
    [Google Scholar]
  81. Nesvorný D, Kipping D, Terrell D, Hartman J, Bakos , Buchhave LA 2013. KOI-142, the king of transit variations, is a pair of planets near the 2:1 resonance. Astrophys. J. 777:3
    [Google Scholar]
  82. Nesvorný D, Kipping DM, Buchhave LA, Bakos , Hartman J, Schmitt AR 2012. The detection and characterization of a nontransiting planet by transit timing variations. Science 336:1133–36
    [Google Scholar]
  83. Nesvorný D, Vokrouhlický D 2014. The effect of conjunctions on the transit timing variations of exoplanets. Astrophys. J. 790:58
    [Google Scholar]
  84. Nesvorný D, Vokrouhlický D 2016. Dynamics and transit variations of resonant exoplanets. Astrophys. J. 823:72
    [Google Scholar]
  85. Ofir A, Dreizler S, Zechmeister M, Husser TO 2014. An independent planet search in the Kepler dataset. II. An extremely low-density super-Earth mass planet around Kepler-87. Astron. Astrophys. 561:A103
    [Google Scholar]
  86. Osborn HP, Santerne A, Barros SCC, Santos NC, Dumusque X et al. 2017. K2-110 b: a massive mini-Neptune exoplanet. Astron. Astrophys. 604:A19
    [Google Scholar]
  87. Owen JE, Morton TD 2016. The initial physical conditions of Kepler-36 b and c. Astrophys. J. Lett. 819:L10
    [Google Scholar]
  88. Owen JE, Wu Y 2013. Kepler planets: a tale of evaporation. Astrophys. J. 775:105
    [Google Scholar]
  89. Owen JE, Wu Y 2016. Atmospheres of low-mass planets: the “boil-off.”. Astrophys. J. 817:107
    [Google Scholar]
  90. Owen JE, Wu Y 2017. The evaporation valley in the Kepler planets. Astrophys. J. 847:29
    [Google Scholar]
  91. Pepe F, Cameron AC, Latham DW, Molinari E, Udry S et al. 2013. An Earth-sized planet with an Earth-like density. Nature 503:377–80
    [Google Scholar]
  92. Petrovich C, Deibert E, Wu Y 2018. Ultra-short-period planets from secular chaos. arXiv:1804.05065 [astro-ph.EP]
  93. Ragozzine D, Holman MJ 2010. The value of systems with multiple transiting planets. arXiv:1006.3727 [astro-ph.EP]
  94. Rajpaul V, Aigrain S, Roberts S 2016. Ghost in the time series: no planet for Alpha Cen B. Mon. Not. R. Astron. Soc. 456:L6–10
    [Google Scholar]
  95. Rappaport S, Barclay T, DeVore J, Rowe J, Sanchis-Ojeda R, Still M 2014. KOI-2700b: a planet candidate with dusty effluents on a 22 hr orbit. Astrophys. J. 784:40
    [Google Scholar]
  96. Rappaport S, Sanchis-Ojeda R, Rogers LA, Levine A, Winn JN 2013. The Roche limit for close-orbiting planets: minimum density, composition constraints, and application to the 4.2 hr planet KOI 1843.03. Astrophys. J. Lett. 773:L15
    [Google Scholar]
  97. Ribas I, Guinan EF, Güdel M, Audard M 2005. Evolution of the solar activity over time and effects on planetary atmospheres. I. High-energy irradiances (1–1700 Å). Astrophys. J. 622:680–94
    [Google Scholar]
  98. Ricker GR, Winn JN, Vanderspek R, Latham DW, Bakos et al. 2014. Transiting Exoplanet Survey Satellite (TESS). SPIE Proceedings 9143 Space Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wave 20–34 Bellingham, WA: SPIE
    [Google Scholar]
  99. Robertson P, Roy A, Mahadevan S 2015. Stellar activity mimics a habitable-zone planet around Kapteyn's star. Astrophys. J. Lett. 805:L22
    [Google Scholar]
  100. Rogers LA 2015. Most 1.6 Earth-radius planets are not rocky. Astrophys. J. 801:41
    [Google Scholar]
  101. Rogers LA, Bodenheimer P, Lissauer JJ, Seager S 2011. Formation and structure of low-density exo-Neptunes. Astrophys. J. 738:59
    [Google Scholar]
  102. Rowe JF, Bryson ST, Marcy GW, Lissauer JJ, Jontof-Hutter D et al. 2014. Validation of Kepler's multiple planet candidates. III. Light curve analysis and announcement of hundreds of new multi-planet systems. Astrophys. J. 784:45
    [Google Scholar]
  103. Sanchis-Ojeda R, Rappaport S, Winn JN, Kotson MC, Levine A, El Mellah I 2014. A study of the shortest-period planets found with Kepler. Astrophys. J. 787:47
    [Google Scholar]
  104. Santerne A, Brugger B, Armstrong DJ, Adibekyan V, Lillo-Box J et al. 2018. An Earth-sized exoplanet with a Mercury-like composition. Nat. Astron. 2:393–400
    [Google Scholar]
  105. Schneider J, Dedieu C, Le Sidaner P, Savalle R, Zolotukhin I 2011. Defining and cataloging exoplanets: the exoplanet.eu database. Astron. Astrophys. 532:A79
    [Google Scholar]
  106. Seager S, Kuchner M, Hier-Majumder CA, Militzer B 2007. Mass-radius relationships for solid exoplanets. Astrophys. J. 669:1279–97
    [Google Scholar]
  107. Seager S, Mallén-Ornelas G 2003. A unique solution of planet and star parameters from an extrasolar planet transit light curve. Astrophys. J. 585:1038–55
    [Google Scholar]
  108. Sheets HA, Deming D 2017. Average albedos of close-in super-Earths and super-Neptunes from statistical analysis of long-cadence Kepler secondary eclipse data. Astron. J. 154:160
    [Google Scholar]
  109. Sinukoff E, Howard AW, Petigura EA, Schlieder JE, Crossfield IJM et al. 2016. Eleven multiplanet systems from K2 campaigns 1 and 2 and the masses of two hot super-Earths. Astrophys. J. 827:78
    [Google Scholar]
  110. Smith RF, Fratanduono DE, Braun DG, Duffy TS, Wicks JK et al. 2018. Equation of state of iron under core conditions of large rocky exoplanets. Nat. Astron. 2:452–58
    [Google Scholar]
  111. Spake JJ, Sing DK, Evans TM, Oklopčić A, Bourrier V et al. 2018. Helium in the eroding atmosphere of an exoplanet. Nature 557:68–70
    [Google Scholar]
  112. Stassun KG, Oelkers RJ, Pepper J, Paegert M, De Lee N et al. 2018. The TESS Input Catalog and Candidate Target List. Astron. J. 156:102
    [Google Scholar]
  113. Steffen JH 2016. Sensitivity bias in the mass-radius distribution from transit timing variations and radial velocity measurements. Mon. Not. R. Astron. Soc. 457:4384–92
    [Google Scholar]
  114. Steffen JH, Fabrycky DC, Agol E, Ford EB, Morehead RC et al. 2013. Transit timing observations from Kepler. VII. Confirmation of 27 planets in 13 multiplanet systems via transit timing variations and orbital stability. Mon. Not. R. Astron. Soc. 428:1077–87
    [Google Scholar]
  115. Stevenson KB 2016. Quantifying and predicting the presence of clouds in exoplanet atmospheres. Astrophys. J. Lett. 817:L16
    [Google Scholar]
  116. Thomas SW, Madhusudhan N 2016. In hot water: effects of temperature-dependent interiors on the radii of water-rich super-Earths. Mon. Not. R. Astron. Soc. 458:1330–44
    [Google Scholar]
  117. Unterborn CT, Dismukes EE, Panero WR 2016. Scaling the Earth: a sensitivity analysis of terrestrial exoplanetary interior models. Astrophys. J. 819:32
    [Google Scholar]
  118. Valencia D, O'Connell RJ, Sasselov D 2006. Internal structure of massive terrestrial planets. Icarus 181:545–54
    [Google Scholar]
  119. van Lieshout R, Min M, Dominik C 2014. Dusty tails of evaporating exoplanets. I. Constraints on the dust composition. Astron. Astrophys. 572:A76
    [Google Scholar]
  120. Vanderburg A, Becker JC, Buchhave LA, Mortier A, Lopez E et al. 2017. Precise masses in the WASP-47 system. Astron. J. 154:237
    [Google Scholar]
  121. Vanderburg A, Plavchan P, Johnson JA, Ciardi DR, Swift J, Kane SR 2016. Radial velocity planet detection biases at the stellar rotational period. Mon. Not. R. Astron. Soc. 459:3565–73
    [Google Scholar]
  122. von Braun K, Boyajian TS, ten Brummelaar TA, Kane SR, van Belle GT et al. 2011. 55 Cancri: stellar astrophysical parameters, a planet in the habitable zone, and implications for the radius of a transiting super-Earth. Astrophys. J. 740:49
    [Google Scholar]
  123. Wagner FW, Sohl F, Hussmann H, Grott M, Rauer H 2011. Interior structure models of solid exoplanets using material laws in the infinite pressure limit. Icarus 214:366–76
    [Google Scholar]
  124. Wagner FW, Tosi N, Sohl F, Rauer H, Spohn T 2012. Rocky super-Earth interiors: structure and internal dynamics of CoRoT-7b and Kepler-10b. Astron. Astrophys. 541:A103
    [Google Scholar]
  125. Wakeford HR, Sing DK, Kataria T, Deming D, Nikolov N et al. 2017. HAT-P-26b: a Neptune-mass exoplanet with a well-constrained heavy element abundance. Science 356:628–31
    [Google Scholar]
  126. Weiss LM, Marcy GW 2014. The mass-radius relation for 65 exoplanets smaller than 4 Earth radii. Astrophys. J. Lett. 783:L6
    [Google Scholar]
  127. Weiss LM, Marcy GW, Petigura EA, Fulton BJ, Howard AW et al. 2018. The California-Kepler Survey. V. Peas in a pod: planets in a Kepler multi-planet system are similar in size and regularly spaced. Astron. J. 155:48
    [Google Scholar]
  128. Weiss LM, Marcy GW, Rowe JF, Howard AW, Isaacson H et al. 2013. The mass of KOI-94d and a relation for planet radius, mass, and incident flux. Astrophys. J. 768:14
    [Google Scholar]
  129. Weiss LM, Rogers LA, Isaacson HT, Agol E, Marcy GW et al. 2016. Revised masses and densities of the planets around Kepler-10. Astrophys. J. 819:83
    [Google Scholar]
  130. Winn JN 2011. Exoplanet transits and occultations. Exoplanets S Seager55–78 Tucson: Univ. Arizona Press
    [Google Scholar]
  131. Winn JN, Matthews JM, Dawson RI, Fabrycky D, Holman MJ et al. 2011. A super-Earth transiting a naked-eye star. Astrophys. J. Lett. 737:L18
    [Google Scholar]
  132. Winn JN, Sanchis-Ojeda R, Rappaport S 2018. Kepler-78 and the ultra-short-period planets. arXiv:1803.03303 [astro-ph.EP]
  133. Wolfgang A, Lopez E 2015. How rocky are they? The composition distribution of Kepler's sub-Neptune planet candidates within 0.15 AU. Astrophys. J. 806:183
    [Google Scholar]
  134. Wolfgang A, Rogers LA, Ford EB 2016. Probabilistic mass-radius relationship for sub-Neptune-sized planets. Astrophys. J. 825:19
    [Google Scholar]
  135. Wright JT, Fakhouri O, Marcy GW, Han E, Feng Y et al. 2011. The exoplanet orbit database. Publ. Astron. Soc. Pac. 123:412
    [Google Scholar]
  136. Wu Y, Lithwick Y 2013. Density and eccentricity of Kepler planets. Astrophys. J. 772:74
    [Google Scholar]
  137. Xie JW 2014. Transit timing variation of near-resonance planetary pairs. II. Confirmation of 30 planets in 15 multiple-planet systems. Astrophys. J. Suppl. 210:25
    [Google Scholar]
  138. Zeng L, Sasselov D 2013. A detailed model grid for solid planets from 0.1 through 100 Earth masses. Publ. Astron. Soc. Pac. 125:227
    [Google Scholar]
  139. Zeng L, Sasselov D 2014. The effect of temperature evolution on the interior structure of HO-rich planets. Astrophys. J. 784:96
    [Google Scholar]
  140. Zeng L, Sasselov DD, Jacobsen SB 2016. Mass-radius relation for rocky planets based on PREM. Astrophys. J. 819:127
    [Google Scholar]
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