ORCID Profile
0000-0001-7506-5640
Current Organisation
Louisiana State University
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Publisher: American Astronomical Society
Date: 28-12-2017
Publisher: American Astronomical Society
Date: 21-01-2019
Publisher: Oxford University Press (OUP)
Date: 10-2013
Publisher: American Astronomical Society
Date: 14-08-2020
Abstract: We present the discoveries of KELT-25 b (TIC 65412605, TOI-626.01) and KELT-26 b (TIC 160708862, TOI-1337.01), two transiting companions orbiting relatively bright, early A stars. The transit signals were initially detected by the KELT survey and subsequently confirmed by Transiting Exoplanet Survey Satellite (TESS) photometry. KELT-25 b is on a 4.40 day orbit around the V = 9.66 star CD-24 5016 ( K, M ⋆ = M ⊙ ), while KELT-26 b is on a 3.34 day orbit around the V = 9.95 star HD 134004 ( = K, M ⋆ = M ⊙ ), which is likely an Am star. We have confirmed the substellar nature of both companions through detailed characterization of each system using ground-based and TESS photometry, radial velocity measurements, Doppler tomography, and high-resolution imaging. For KELT-25, we determine a companion radius of R P = R J and a 3 σ upper limit on the companion’s mass of ∼64 M J . For KELT-26 b, we infer a planetary mass and radius of M P = and R P = R J . From Doppler tomographic observations, we find KELT-26 b to reside in a highly misaligned orbit. This conclusion is weakly corroborated by a subtle asymmetry in the transit light curve from the TESS data. KELT-25 b appears to be in a well-aligned, prograde orbit, and the system is likely a member of the cluster Theia 449.
Publisher: American Astronomical Society
Date: 11-2018
Publisher: EDP Sciences
Date: 05-2013
Publisher: Springer Science and Business Media LLC
Date: 06-2017
DOI: 10.1038/NATURE22392
Abstract: The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extrasolar planets now known, only six have been found that transit hot, A-type stars (with temperatures of 7,300-10,000 kelvin), and no planets are known to transit the even hotter B-type stars. For ex le, WASP-33 is an A-type star with a temperature of about 7,430 kelvin, which hosts the hottest known transiting planet, WASP-33b (ref. 1) the planet is itself as hot as a red dwarf star of type M (ref. 2). WASP-33b displays a large heat differential between its dayside and nightside, and is highly inflated-traits that have been linked to high insolation. However, even at the temperature of its dayside, its atmosphere probably resembles the molecule-dominated atmospheres of other planets and, given the level of ultraviolet irradiation it experiences, its atmosphere is unlikely to be substantially ablated over the lifetime of its star. Here we report observations of the bright star HD 195689 (also known as KELT-9), which reveal a close-in (orbital period of about 1.48 days) transiting giant planet, KELT-9b. At approximately 10,170 kelvin, the host star is at the iding line between stars of type A and B, and we measure the dayside temperature of KELT-9b to be about 4,600 kelvin. This is as hot as stars of stellar type K4 (ref. 5). The molecules in K stars are entirely dissociated, and so the primary sources of opacity in the dayside atmosphere of KELT-9b are probably atomic metals. Furthermore, KELT-9b receives 700 times more extreme-ultraviolet radiation (that is, with wavelengths shorter than 91.2 nanometres) than WASP-33b, leading to a predicted range of mass-loss rates that could leave the planet largely stripped of its envelope during the main-sequence lifetime of the host star.
Publisher: American Astronomical Society
Date: 23-04-2013
Publisher: American Astronomical Society
Date: 27-03-2017
Publisher: American Astronomical Society
Date: 30-08-2017
Publisher: American Astronomical Society
Date: 14-11-2012
Publisher: Oxford University Press (OUP)
Date: 12-07-2013
DOI: 10.1093/MNRAS/STT927
Publisher: American Astronomical Society
Date: 09-06-2017
Publisher: American Astronomical Society
Date: 13-08-2012
Publisher: EDP Sciences
Date: 27-03-2013
Publisher: American Astronomical Society
Date: 24-07-2019
Publisher: American Astronomical Society
Date: 27-11-2013
Publisher: American Astronomical Society
Date: 02-2012
Publisher: American Astronomical Society
Date: 17-01-2013
Publisher: American Astronomical Society
Date: 06-05-2013
Publisher: Oxford University Press (OUP)
Date: 04-11-2014
Publisher: American Astronomical Society
Date: 23-09-2014
Publisher: American Astronomical Society
Date: 10-04-2018
Publisher: American Astronomical Society
Date: 25-11-2015
Publisher: American Astronomical Society
Date: 31-08-2022
Abstract: We report the light-curve analysis for the event MOA-2020-BLG-135, which leads to the discovery of a new Neptune-class planet, MOA-2020-BLG-135Lb. With a derived mass ratio of q = 1.52 − 0.31 + 0.39 × 10 − 4 and separation s ≈ 1, the planet lies exactly at the break and likely peak of the exoplanet mass-ratio function derived by the Microlensing Observations in Astrophysics (MOA) Collaboration. We estimate the properties of the lens system based on a Galactic model and considering two different Bayesian priors: one assuming that all stars have an equal planet-hosting probability and the other that planets are more likely to orbit more-massive stars. With a uniform host mass prior, we predict that the lens system is likely to be a planet of mass m planet = 11.3 − 6.9 + 19.2 M ⊕ and a host star of mass M host = 0.23 − 0.14 + 0.39 M ⊙ , located at a distance D L = 7.9 − 1.0 + 1.0 kpc . With a prior that holds that planet occurrence scales in proportion to the host-star mass, the estimated lens system properties are m planet = 25 − 15 + 22 M ⊕ , M host = 0.53 − 0.32 + 0.42 M ⊙ , and D L = 8.3 − 1.0 + 0.9 kpc . This planet qualifies for inclusion in the extended MOA-II exoplanet microlens s le.
Publisher: American Astronomical Society
Date: 09-09-2015
Publisher: American Astronomical Society
Date: 20-10-2016
Publisher: American Astronomical Society
Date: 23-10-2019
Publisher: American Astronomical Society
Date: 02-05-2012
Publisher: American Astronomical Society
Date: 06-07-2012
Publisher: Cambridge University Press (CUP)
Date: 10-2010
DOI: 10.1017/S1743921311020424
Abstract: The discovery of extrasolar planets is arguably the most exciting development in astrophysics during the past 15 years, rivalled only by the detection of dark energy. Two projects are now at the intersection of the two communities of exoplanet scientists and cosmologists: EUCLID, proposed as an ESA M-class mission and WFIRST, the top-ranked large space mission for the next decade by the Astro 2010 Decadal Survey report. The missions are to have several important science programs: a dark energy survey using weak lensing, baryon acoustic oscillations, Type Ia supernova, a survey of exoplanetary architectures using microlensing, and different surveys. The WFIRST and EUCLID microlensing planet search programs will provide a statistical census of exoplanets with masses greater than the mass of Mars and orbital separations ranging from 0.5 AU outwards, including free-floating planets. This will include analogs of all Solar System planets except for Mercury, as well as most types of planets predicted by planet formation theories. In combination with Kepler's census of planets in shorter period orbits, EUCLID and WFIRST's planet search programs will provide a complete statistical census of the planets that populate our Galaxy. As of today, EUCLID is proposed to ESA as a M class mission (the result of the selection will be known in october 2011). We are presenting here preliminary results about the expected planet yields. WFIRST has just appointed a Science Definition Team.
Publisher: American Astronomical Society
Date: 31-07-2012
Publisher: American Astronomical Society
Date: 27-04-2015
Publisher: EDP Sciences
Date: 25-06-2013
Publisher: American Astronomical Society
Date: 08-01-2013
Publisher: American Astronomical Society
Date: 19-05-2017
Publisher: American Astronomical Society
Date: 24-03-2023
Abstract: We analyze the MOA-2020-BLG-208 gravitational microlensing event and present the discovery and characterization of a new planet, MOA-2020-BLG-208Lb, with an estimated sub-Saturn mass. With a mass ratio q = 3.17 − 0.26 + 0.28 × 10 − 4 , the planet lies near the peak of the mass-ratio function derived by the MOA collaboration and near the edge of expected s le sensitivity. For these estimates we provide results using two mass-law priors: one assuming that all stars have an equal planet-hosting probability, and the other assuming that planets are more likely to orbit around more massive stars. In the first scenario, we estimate that the lens system is likely to be a planet of mass m planet = 46 − 24 + 42 M ⊕ and a host star of mass M host = 0.43 − 0.23 + 0.39 M ⊙ , located at a distance D L = 7.49 − 1.13 + 0.99 kpc . For the second scenario, we estimate m planet = 69 − 34 + 37 M ⊕ , M host = 0.66 − 0.32 + 0.35 M ⊙ , and D L = 7.81 − 0.93 + 0.93 kpc . The planet has a projected separation as a fraction of the Einstein ring radius s = 1.3807 − 0.0018 + 0.0018 . As a cool sub-Saturn-mass planet, this planet adds to a growing collection of evidence for revised planetary formation models.
Publisher: American Astronomical Society
Date: 02-2018
Publisher: American Astronomical Society
Date: 21-12-2017
Publisher: IOP Publishing
Date: 25-10-2016
Publisher: American Astronomical Society
Date: 27-01-2014
No related grants have been discovered for Matthew Penny.