Bibcode
Kuzuhara, Masayuki; Montañes, P.; Korth, Judith; Hatzes, Artie P.; Grziwa, Sascha; Guenther, Eike W.; Fukui, A.; Fridlund, Malcolm; Erikson, Anders; Eigmüller, Philipp; Deeg, H.; de Leon, Jerome P.; Csizmadia, Szilard; Cabrera, Juan; Barragan, Oscar; Albrecht, Simon; Endl, Michael; Cochran, William D.; Nowak, G.; Trani, Alessandro A.; Gandolfi, Davide; Hirano, Teruyuki; Dai, Fei; Livingston, John H.; Narita, N.; Nespral, D.; Palle, E.; Pätzold, Martin; Persson, Carina M.; Prieto-Arranz, J.; Rauer, Heike; Tamura, Motohide; Van Eylen, Vincent; Winn, Joshua N.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 484, Issue 1, p.8-18
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3
2019
Citations
33
Refereed citations
29
Description
Planet host stars with well-constrained ages provide a rare window to
the time domain of planet formation and evolution. The NASA K2 mission
has enabled the discovery of the vast majority of known planets
transiting stars in clusters, providing a valuable sample of planets
with known ages and radii. We present the discovery of two planets
transiting K2-264, an M2 dwarf in the intermediate age (600-800 Myr)
Praesepe open cluster (also known as the Beehive Cluster, M44, or NGC
2632), which was observed by K2 during Campaign 16. The planets have
orbital periods of 5.8 and 19.7 d, and radii of 2.2 ± 0.2 and 2.7
± 0.2R⊕, respectively, and their equilibrium
temperatures are 496 ± 10 and 331 ± 7 K, making this a
system of two warm sub-Neptunes. When placed in the context of known
planets orbiting field stars of similar mass to K2-264, these planets do
not appear to have significantly inflated radii, as has previously been
noted for some cluster planets. As the second known system of multiple
planets transiting a star in a cluster, K2-264 should be valuable for
testing theories of photoevaporation in systems of multiple planets.
Follow-up observations with current near-infrared (NIR) spectrographs
could yield planet mass measurements, which would provide information
about the mean densities and compositions of small planets soon after
photoevaporation is expected to have finished. Follow-up NIR transit
observations using Spitzer or large ground-based telescopes could yield
improved radius estimates, further enhancing the characterization of
these interesting planets.
Related projects
Exoplanets and Astrobiology
The search for life in the universe has been driven by recent discoveries of planets around other stars (known as exoplanets), becoming one of the most active fields in modern astrophysics. The growing number of new exoplanets discovered in recent years and the recent advance on the study of their atmospheres are not only providing new valuable
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