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Author Bergsten, G.J.; Pascucci, I.; Mulders, G.D.; Fernandes, R.B.; Koskinen, T.T.
Title The Demographics of Kepler's Earths and Super-Earths into the Habitable Zone Type
Year 2022 Publication Astronomical Journal Abbreviated Journal Astron. J.
Volume 164 Issue 5 Pages 190
Keywords POWERED MASS-LOSS; PLANET OCCURRENCE RATES; RADIUS DISTRIBUTION; RELIABILITY; DEPENDENCE; EXOPLANETS; MISSION; VALLEY; TRENDS
Abstract Understanding the occurrence of Earth-sized planets in the habitable zone of Sun-like stars is essential to the search for Earth analogs. Yet a lack of reliable Kepler detections for such planets has forced many estimates to be derived from the close-in (2 < P-orb < 100 days) population, whose radii may have evolved differently under the effect of atmospheric mass-loss mechanisms. In this work, we compute the intrinsic occurrence rates of close-in super-Earths (similar to 1-2 R-circle plus and sub-Neptunes (similar to 2-3.5 R-circle plus) for FGK stars (0.56-1.63 M-circle dot) as a function of orbital period and find evidence of two regimes: where super-Earths are more abundant at short orbital periods, and where sub-Neptunes are more abundant at longer orbital periods. We fit a parametric model in five equally populated stellar mass bins and find that the orbital period of transition between these two regimes scales with stellar mass, like P-trans proportional to M-*(1.7 +/- 0.2). Ptrans These results suggest a population of former sub-Neptunes contaminating the population of gigayear-old close-in super-Earths, indicative of a population shaped by atmospheric loss. Using our model to constrain the long-period population of intrinsically rocky planets, we estimate an occurrence rate of Gamma(circle plus) = 15(-4)(+6)% for Earth-sized habitable zone planets, and predict that sub-Neptunes may be similar to twice as common as super-Earths in the habitable zone (when normalized over the natural log-orbital period and radius range used). Finally, we discuss our results in the context of future missions searching for habitable zone planets.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6256 ISBN Medium
Area Expedition Conference
Notes WOS:000867413100001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1665
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Author Fernandes, R.B.; Mulders, G.D.; Pascucci, I.; Bergsten, G.J.; Koskinen, T.T.; Hardegree-Ullman, K.K.; Pearson, K.A.; Giacalone, S.; Zink, J.; Ciardi, D.R.; O'Brien, P.
Title pterodactyls: A Tool to Uniformly Search and Vet for Young Transiting Planets in TESS Primary Mission Photometry Type
Year 2022 Publication Astronomical Journal Abbreviated Journal Astron. J.
Volume 164 Issue 3 Pages 78
Keywords POWERED MASS-LOSS; ZODIACAL EXOPLANETS; RADIUS DISTRIBUTION; DWARF; HUNT; STAR; FREQUENCY; EFFICIENT; KEPLER; SYSTEM
Abstract Kepler's short-period exoplanet population has revealed evolutionary features such as the Radius Valley and the Hot Neptune desert that are likely sculpted by atmospheric loss over time. These findings suggest that the primordial planet population is different from the Gyr-old Kepler population, and motivates exoplanet searches around young stars. Here, we present pterodactyls, a data reduction pipeline specifically built to address the challenges in discovering exoplanets around young stars and to work with TESS Primary Mission 30-minute cadence photometry, since most young stars were not preselected TESS two-minute cadence targets. pterodactyls builds on publicly available and tested tools in order to extract, detrend, search, and vet transiting young planet candidates. We search five clusters with known transiting planets: the Tucana-Horologium Association, IC 2602, Upper Centaurus Lupus, Ursa Major, and Pisces-Eridani. We show that pterodactyls recovers seven out of the eight confirmed planets and one out of the two planet candidates, most of which were initially detected in two-minute cadence data. For these clusters, we conduct injection-recovery tests to characterize our detection efficiency, and compute an intrinsic planet occurrence rate of 49% +/- 20% for sub-Neptunes and Neptunes (1.8-6 R (circle plus)) within 12.5 days, which is higher than Kepler's Gyr-old occurrence rates of 6.8% +/- 0.3%. This potentially implies that these planets have shrunk with time due to atmospheric mass loss. However, a proper assessment of the occurrence of transiting young planets will require a larger sample unbiased to planets already detected. As such, pterodactyls will be used in future work to search and vet for planet candidates in nearby clusters and moving groups.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6256 ISBN Medium
Area Expedition Conference
Notes WOS:000835823800001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1636
Permanent link to this record