Physical Parameters of the Multiplanet Systems HD 106315 and GJ 9827* †
Autor: | Lee J. Rosenthal, S. Giacalone, Charles Beichman, Stephen R. Kane, Andrew W. Howard, Ryan A. Rubenzahl, Benjamin J. Fulton, Samuel K. Grunblatt, Gregory W. Henry, Jessica Krick, Howard Isaacson, Michelle L. Hill, Aida Behmard, Stephen A. Shectman, Sharon X. Wang, David Berardo, Malena Rice, Cesar Laguna, Paul A. Dalba, Ashley Chontos, Fei Dai, Varoujan Gorjian, Qingtian Liu, Steve B. Howell, Johanna Teske, Lea A. Hirsch, Jessie L. Christiansen, Caroline Piaulet, Chiara Dane Villanueva, Joseph M. Akana Murphy, Ian Crossfield, Farisa Y. Morales, Teo Mocnik, Nicholas J. Scott, Michael W. Werner, Laura Kreidberg, J. Burt, John H. Livingston, Caroline Morley, Sean M. Mills, Lauren M. Weiss, Erik A. Petigura, Molly R. Kosiarek, Jeffrey D. Crane, Andrew W. Mayo |
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Rok vydání: | 2020 |
Předmět: |
Radial velocity
010504 meteorology & atmospheric sciences FOS: Physical sciences chemistry.chemical_element Astrophysics Ephemeris 01 natural sciences Gaussian Processes regression Planet 0103 physical sciences Transit (astronomy) Spectroscopy Mini Neptunes Super Earths 010303 astronomy & astrophysics Helium 0105 earth and related environmental sciences Earth and Planetary Astrophysics (astro-ph.EP) Physics Exoplanets Astronomy and Astrophysics Exoplanet PRECISION Stars chemistry Space and Planetary Science ARRAY Transit photometry PLANETS Astrophysics - Earth and Planetary Astrophysics |
Zdroj: | Kosiarek, M R, Berardo, D A, Crossfield, I J M, Laguna, C, Piaulet, C, Akana Murphy, J M, Howell, S B, Henry, G W, Isaacson, H, Fulton, B, Weiss, L M, Petigura, E A, Behmard, A, Hirsch, L A, Teske, J, Burt, J A, Mills, S M, Chontos, A, Mocnik, T, Howard, A W, Werner, M, Livingston, J H, Krick, J, Beichman, C, Gorjian, V, Kreidberg, L, Morley, C, Christiansen, J L, Morales, F Y, Scott, N J, Crane, J D, Wang, S X, Shectman, S A, Rosenthal, L J, Grunblatt, S K, Rubenzahl, R A, Dalba, P A, Giacalone, S, Villanueva, C D, Liu, Q, Dai, F, Hill, M L, Rice, M, Kane, S R & Mayo, A W 2021, ' Physical Parameters of the Multiplanet Systems HD 106315 and GJ 9827*dagger ', Astronomical Journal, vol. 161, no. 1, 47 . https://doi.org/10.3847/1538-3881/abca39 |
ISSN: | 1538-3881 0004-6256 |
Popis: | HD 106315 and GJ 9827 are two bright, nearby stars that host multiple super-Earths and sub-Neptunes discovered by K2 that are well suited for atmospheric characterization. We refined the planets’ ephemerides through Spitzer transits, enabling accurate transit prediction required for future atmospheric characterization through transmission spectroscopy. Through a multiyear high-cadence observing campaign with Keck/High Resolution Echelle Spectrometer and Magellan/Planet Finder Spectrograph, we improved the planets’ mass measurements in anticipation of Hubble Space Telescope transmission spectroscopy. For GJ 9827, we modeled activity-induced radial velocity signals with a Gaussian process informed by the Calcium II H&K lines in order to more accurately model the effect of stellar noise on our data. We measured planet masses of M b = 4.87 ± 0.37 M ⊕, M c = 1.92 ± 0.49 M ⊕, and M d = 3.42 ± 0.62 M ⊕. For HD 106315, we found that such activity radial velocity decorrelation was not effective due to the reduced presence of spots and speculate that this may extend to other hot stars as well (T eff > 6200 K). We measured planet masses of M b = 10.5 ± 3.1 M ⊕ and M c = 12.0 ± 3.8 M ⊕. We investigated all of the planets’ compositions through comparison of their masses and radii to a range of interior models. GJ 9827 b and GJ 9827 c are both consistent with a 50/50 rock-iron composition, GJ 9827 d and HD 106315 b both require additional volatiles and are consistent with moderate amounts of water or hydrogen/helium, and HD 106315 c is consistent with a ∼10% hydrogen/helium envelope surrounding an Earth-like rock and iron core. |
Databáze: | OpenAIRE |
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