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KELT-23Ab: A Hot Jupiter Transiting a Near-solar Twin Close to the TESS and JWST Continuous Viewing Zones
We announce the discovery of KELT-23Ab, a hot Jupiter transiting the relatively bright (V = 10.3) star BD+66 911 (TYC 4187-996-1), and characterize the system using follow-up photometry and spectroscopy. A global fit to the system yields host-star properties of T-eff = 5900 +/- 49 K, M* = 0.945(-0.054)(+0.060) M-circle dot, R* = 0.995 +/- 0.015 R-circle dot, L* = 1.082(-0.048)(+0.051) L-circle dot, log g* = 4.418(-0.025)(+0.026). (cgs), and [Fe/H] = -0.105 +/- 0.077. KELT-23Ab is a hot Jupiter with a mass of M-p = 0.938(-0.042)(+0.045). M-J, radius of R-p = 1.322 0.025 R-J, and density of rho(p) = 0.504(0.035)(+0.038) g cm(-3). Intense insolation flux from the star has likely caused KELT-23Ab to become inflated. The time of inferior conjunction is T-0 = 2458149.40776 +/- 0.00091 BJD(TDB) and the orbital period is P = 2.255353(-0.000030)(+0.000031) ON days. There is strong evidence that KELT-23A is a member of a long-period binary star system with a less luminous companion, and due to tidal interactions, the planet is likely to spiral into its host within roughly a gigayear. This system has one of the highest positive ecliptic latitudes of all transiting planet hosts known to date, placing it near the Transiting Planet Survey Satellite and James Webb Space Telescope continuous viewing zones. Thus we expect it to be an excellent candidate for long-term monitoring and follow up with these facilities.Ohio State University; Vanderbilt University; Lehigh University; Harvard Future Faculty Leaders Postdoctoral fellowship; NSF CAREER Grant [AST-1056524]; National Science Foundation [DGE-1343012, 1559487]; Space Telescope Science Institute [HST-HF2-51402.001-A]; NASA [NAS 5-26555, 80NSSC18K1009, NNX17AB94G]; National Aeronautics and Space Administration; FAPESP [2017/23731-1]; Carol and Ray Neag Undergraduate Research Fund; KELT follow-up collaborationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
KELT-2Ab: A Hot Jupiter Transiting the Bright (V = 8.77) Primary Star of a Binary System
We report the discovery of KELT-2Ab, a hot Jupiter transiting the bright (V = 8.77) primary star of the HD 42176 binary system. The host is a slightly evolved late F-star likely in the very short-lived "blue-hook" stage of evolution, with T_(eff) = 6148 ± 48 K, log g = 4.030^(+0.015)_(–0.026) and [Fe/H] = 0.034 ± 0.78. The inferred stellar mass is M* = 1.314^(+0.063)_(–0.060) M☉ and the star has a relatively large radius of R* = 1.836^(+0.066)_(–0.046) R☉. The planet is a typical hot Jupiter with period 4.1137913 ± 0.00001 days and a mass of M_P = 1.524 ± 0.088 M J and radius of R_P = 1.290^(+0.064)_(–0.050) R_J. This is mildly inflated as compared to models of irradiated giant planets at the ~4 Gyr age of the system. KELT-2A is the third brightest star with a transiting planet identified by ground-based transit surveys, and the ninth brightest star overall with a transiting planet. KELT-2Ab's mass and radius are unique among the subset of planets with V < 9 host stars, and therefore increases the diversity of bright benchmark systems. We also measure the relative motion of KELT-2A and -2B over a baseline of 38 years, robustly demonstrating for the first time that the stars are bound. This allows us to infer that KELT-2B is an early K dwarf. We hypothesize that through the eccentric Kozai mechanism KELT-2B may have emplaced KELT-2Ab in its current orbit. This scenario is potentially testable with Rossiter-McLaughlin measurements, which should have an amplitude of ~44 m s^(–1)
ERTS-1 imagery use in reconnaissance prospecting: Evaluation of commercial utility of ERTS-1 imagery in structural reconnaissance for minerals and petroleum
The author has identified the following significant results. This study was performed to investigate applications of ERTS-1 imagery in commercial reconnaissance for mineral and hydrocarbon resources. ERTS-1 imagery collected over five areas in North America (Montana; Colorado; New Mexico-West Texas; Superior Province, Canada; and North Slope, Alaska) has been analyzed for data content including linears, lineaments, and curvilinear anomalies. Locations of these features were mapped and compared with known locations of mineral and hydrocarbon accumulations. Results were analyzed in the context of a simple-shear, block-coupling model. Data analyses have resulted in detection of new lineaments, some of which may be continental in extent, detection of many curvilinear patterns not generally seen on aerial photos, strong evidence of continental regmatic fracture patterns, and realization that geological features can be explained in terms of a simple-shear, block-coupling model. The conculsions are that ERTS-1 imagery is of great value in photogeologic/geomorphic interpretations of regional features, and the simple-shear, block-coupling model provides a means of relating data from ERTS imagery to structures that have controlled emplacement of ore deposits and hydrocarbon accumulations, thus providing a basis for a new approach for reconnaissance for mineral, uranium, gas, and oil deposits and structures
Spitzer Phase Curves of KELT-1b and the Signatures of Nightside Clouds in Thermal Phase Observations
We observed two full orbital phase curves of the transiting brown dwarf
KELT-1b, at 3.6um and 4.5um, using the Spitzer Space Telescope. Combined with
previous eclipse data from Beatty et al. (2014), we strongly detect KELT-1b's
phase variation as a single sinusoid in both bands, with amplitudes of
ppm at 3.6um and ppm at 4.5um, and confirm the secondary
eclipse depths measured by Beatty et al. (2014). We also measure noticeable
Eastward hotspot offsets of degrees at 3.6um and
degrees at 4.5um. Both the day-night temperature contrasts and the hotspot
offsets we measure are in line with the trends seen in hot Jupiters (e.g.,
Crossfield 2015), though we disagree with the recent suggestion of an offset
trend by Zhang et al. (2018). Using an ensemble analysis of Spitzer phase
curves, we argue that nightside clouds are playing a noticeable role in
modulating the thermal emission from these objects, based on: 1) the lack of a
clear trend in phase offsets with equilibrium temperature, 2) the sharp
day-night transitions required to have non-negative intensity maps, which also
resolves the inversion issues raised by Keating & Cowan (2017), 3) the fact
that all the nightsides of these objects appear to be at roughly the same
temperature of 1000K, while the dayside temperatures increase linearly with
equilibrium temperature, and 4) the trajectories of these objects on a Spitzer
color-magnitude diagram, which suggest colors only explainable via nightside
clouds.Comment: AJ in press. Updated to reflect the accepted versio
Predicting the Yields of Photometric Surveys for Transiting Planets
Observing extrasolar planetary transits is one of the only ways that we may
infer the masses and radii of planets outside the Solar System. As such, the
detections made by photometric transit surveys are one of the only foreseeable
ways that the areas of planetary interiors, system dynamics, migration, and
formation will acquire more data. Predicting the yields of these surveys
therefore serves as a useful statistical tool. Predictions allows us to check
the efficiency of transit surveys (``are we detecting all that we should?'')
and to test our understanding of the relevant astrophysics (``what parameters
affect predictions?''). Furthermore, just the raw numbers of how many planets
will be detected by a survey can be interesting in its own right. Here, we look
at two different approaches to modeling predictions (forward and backward), and
examine three different transit surveys (TrES, XO, and Kepler). In all cases,
making predictions provides valuable insight into both extrasolar planets and
the surveys themselves, but this must be tempered by an appreciation of the
uncertainties in the statistical cut-offs used by the transit surveys.Comment: To appear in the Proceedings of the 253rd IAU Symposium: "Transiting
Planets", May 2008, Cambridge, MA. 7 pages, 2 figures, 2 table
Spin orbit alignment for KELT-7b and HAT-P-56b via Doppler tomography with TRES
We present Doppler tomographic analyses for the spectroscopic transits of
KELT-7b and HAT-P-56b, two hot-Jupiters orbiting rapidly rotating F-dwarf host
stars. These include analyses of archival TRES observations for KELT-7b, and a
new TRES transit observation of HAT-P-56b. We report spin-orbit aligned
geometries for KELT-7b (2.7 +/- 0.6 deg) and HAT-P-56b (8 +/- 2 deg). The host
stars KELT-7 and HAT-P-56 are among some of the most rapidly rotating
planet-hosting stars known. We examine the tidal re-alignment model for the
evolution of the spin-orbit angle in the context of the spin rates of these
stars. We find no evidence that the rotation rates of KELT-7 and HAT-P-56 have
been modified by star-planet tidal interactions, suggesting that the spin-orbit
angle of systems around these hot stars may represent their primordial
configuration. In fact, KELT-7 and HAT-P-56 are two of three systems in
super-synchronous, spin-orbit aligned states, where the rotation periods of the
host stars are faster than the orbital periods of the planets.Comment: 9 pages, accepted for publication in MNRA
KELT-2Ab: A Hot Jupiter Transiting the Bright (V = 8.77) Primary Star of a Binary System
We report the discovery of KELT-2Ab, a hot Jupiter transiting the bright (V = 8.77) primary star of the HD 42176 binary system. The host is a slightly evolved late F-star likely in the very short-lived "blue-hook" stage of evolution, with T_(eff) = 6148 ± 48 K, log g = 4.030^(+0.015)_(–0.026) and [Fe/H] = 0.034 ± 0.78. The inferred stellar mass is M* = 1.314^(+0.063)_(–0.060) M☉ and the star has a relatively large radius of R* = 1.836^(+0.066)_(–0.046) R☉. The planet is a typical hot Jupiter with period 4.1137913 ± 0.00001 days and a mass of M_P = 1.524 ± 0.088 M J and radius of R_P = 1.290^(+0.064)_(–0.050) R_J. This is mildly inflated as compared to models of irradiated giant planets at the ~4 Gyr age of the system. KELT-2A is the third brightest star with a transiting planet identified by ground-based transit surveys, and the ninth brightest star overall with a transiting planet. KELT-2Ab's mass and radius are unique among the subset of planets with V < 9 host stars, and therefore increases the diversity of bright benchmark systems. We also measure the relative motion of KELT-2A and -2B over a baseline of 38 years, robustly demonstrating for the first time that the stars are bound. This allows us to infer that KELT-2B is an early K dwarf. We hypothesize that through the eccentric Kozai mechanism KELT-2B may have emplaced KELT-2Ab in its current orbit. This scenario is potentially testable with Rossiter-McLaughlin measurements, which should have an amplitude of ~44 m s^(–1)
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