TY - JOUR
T1 - Kepler-78 and the Ultra-Short-Period planets
AU - Winn, Joshua N.
AU - Sanchis-Ojeda, Roberto
AU - Rappaport, Saul
N1 - Funding Information:
We thank Jack Lissauer for the invitation to write this review, and Scott Tremaine for helpful consultations. We thank Eve Lee and Eugene Chiang for granting us permission to reproduce Fig. 1 from their 2017 paper (which appears as Fig. 4 in this article). J.N.W. thanks the Heising–Simons foundation for support. We are all deeply grateful to the engineers, managers, and scientists who were reponsible for the Kepler mission which has led to so many important discoveries.
PY - 2018/11
Y1 - 2018/11
N2 - Compared to the Earth, the exoplanet Kepler-78b has a similar size (1.2 R⊕) and an orbital period a thousand times shorter (8.5 h). It is currently the smallest planet for which the mass, radius, and dayside brightness have all been measured. Kepler-78b is an exemplar of the ultra-short-period (USP) planets, a category defined by the simple criterion Porb < 1 day. We describe our Fourier-based search of the Kepler data that led to the discovery of Kepler-78b, and review what has since been learned about the population of USP planets. They are about as common as hot Jupiters, and they are almost always smaller than 2 R⊕. They are often members of compact multi-planet systems, although they tend to have relatively large period ratios and mutual inclinations. They might be the exposed rocky cores of “gas dwarfs,” the planets between 2–4 R⊕ in size that are commonly found in somewhat wider orbits.
AB - Compared to the Earth, the exoplanet Kepler-78b has a similar size (1.2 R⊕) and an orbital period a thousand times shorter (8.5 h). It is currently the smallest planet for which the mass, radius, and dayside brightness have all been measured. Kepler-78b is an exemplar of the ultra-short-period (USP) planets, a category defined by the simple criterion Porb < 1 day. We describe our Fourier-based search of the Kepler data that led to the discovery of Kepler-78b, and review what has since been learned about the population of USP planets. They are about as common as hot Jupiters, and they are almost always smaller than 2 R⊕. They are often members of compact multi-planet systems, although they tend to have relatively large period ratios and mutual inclinations. They might be the exposed rocky cores of “gas dwarfs,” the planets between 2–4 R⊕ in size that are commonly found in somewhat wider orbits.
KW - Planets
KW - Time-series photometry
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U2 - 10.1016/j.newar.2019.03.006
DO - 10.1016/j.newar.2019.03.006
M3 - Review article
AN - SCOPUS:85065541102
SN - 1387-6473
VL - 83
SP - 37
EP - 48
JO - New Astronomy Reviews
JF - New Astronomy Reviews
ER -