147 research outputs found

    A Case-Control Study of Trace-Element Status and Lung Cancer in Appalachian Kentucky

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    Appalachian Kentucky (App KY) leads the nation in lung cancer incidence and mortality. Trace elements, such as As, have been associated with lung cancers in other regions of the country and we hypothesized that a population-based study would reveal higher trace element concentrations in App KY individuals with cancer compared to controls. Using toenail and drinking water trace element concentrations, this study investigated a possible association between lung cancer incidence and trace-element exposure in residents of this region. This population-based case-control study had 520 subjects, and 367 subjects provided toenail samples. Additionally, we explored the relationship between toenail and fingernail trace-element concentrations to determine if fingernails could be used as a surrogate for toenails when patients are unable to provide toenail samples. We found that, contrary to our initial hypothesis, trace element concentrations (Al, As, Cr, Mn, Co, Fe, Ni, Cu, Se, and Pb) were not higher in cancer cases than controls with the exception of Zn where concentrations were slightly higher in cases. In fact, univariate logistic regression models showed that individuals with lower concentrations of several elements (Al, Mn, Cr, and Se) were more likely to have lung cancer, although only Mn was significant in multivariate models which controlled for confounding factors. While drinking water concentrations of Al, Cr and Co were positively related to cancer incidence in univariate models, only Co remained significant in multivariate models. However, since the drinking water concentrations were extremely low and not reflected in the toenail concentrations, the significance of this finding is unclear. We also found that fingernail concentrations were not consistently predictive of toenail concentrations, indicating that fingernails should not be used as surrogates for toenails in future studies

    KELT-7b: A hot Jupiter transiting a bright V=8.54 rapidly rotating F-star

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    We report the discovery of KELT-7b, a transiting hot Jupiter with a mass of 1.28±0.181.28 \pm 0.18 MJ, radius of 1.530.047+0.0461.53_{-0.047}^{+0.046} RJ, and an orbital period of 2.7347749±0.00000392.7347749 \pm 0.0000039 days. The bright host star (HD33643; KELT-7) is an F-star with V=8.54V=8.54, Teff =678949+50=6789_{-49}^{+50} K, [Fe/H] =0.1390.081+0.075=0.139_{-0.081}^{+0.075}, and logg=4.149±0.019\log{g}=4.149 \pm 0.019. It has a mass of 1.5350.054+0.0661.535_{-0.054}^{+0.066} Msun, a radius of 1.7320.045+0.0431.732_{-0.045}^{+0.043} Rsun, and is the fifth most massive, fifth hottest, and the ninth brightest star known to host a transiting planet. It is also the brightest star around which KELT has discovered a transiting planet. Thus, KELT-7b is an ideal target for detailed characterization given its relatively low surface gravity, high equilibrium temperature, and bright host star. The rapid rotation of the star (73±0.573 \pm 0.5 km/s) results in a Rossiter-McLaughlin effect with an unusually large amplitude of several hundred m/s. We find that the orbit normal of the planet is likely to be well-aligned with the stellar spin axis, with a projected spin-orbit alignment of λ=9.7±5.2\lambda=9.7 \pm 5.2 degrees. This is currently the second most rapidly rotating star to have a reflex signal (and thus mass determination) due to a planetary companion measured.Comment: Accepted to The Astronomical Journa

    KELT-6b: A P~7.9 d Hot Saturn Transiting a Metal-Poor Star with a Long-Period Companion

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    We report the discovery of KELT-6b, a mildly-inflated Saturn-mass planet transiting a metal-poor host. The initial transit signal was identified in KELT-North survey data, and the planetary nature of the occulter was established using a combination of follow-up photometry, high-resolution imaging, high-resolution spectroscopy, and precise radial velocity measurements. The fiducial model from a global analysis including constraints from isochrones indicates that the V=10.38 host star (BD+31 2447) is a mildly evolved, late-F star with T_eff=6102 \pm 43 K, log(g_*)=4.07_{-0.07}^{+0.04} and [Fe/H]=-0.28 \pm 0.04, with an inferred mass M_*=1.09 \pm 0.04 M_sun and radius R_star=1.58_{-0.09}^{+0.16} R_sun. The planetary companion has mass M_P=0.43 \pm 0.05 M_J, radius R_P=1.19_{-0.08}^{+0.13} R_J, surface gravity log(g_P)=2.86_{-0.08}^{+0.06}, and density rho_P=0.31_{-0.08}^{+0.07} g~cm^{-3}. The planet is on an orbit with semimajor axis a=0.079 \pm 0.001 AU and eccentricity e=0.22_{-0.10}^{+0.12}, which is roughly consistent with circular, and has ephemeris of T_c(BJD_TDB)=2456347.79679 \pm 0.00036 and P=7.845631 \pm 0.000046 d. Equally plausible fits that employ empirical constraints on the host star parameters rather than isochrones yield a larger planet mass and radius by ~4-7%. KELT-6b has surface gravity and incident flux similar to HD209458b, but orbits a host that is more metal poor than HD209458 by ~0.3 dex. Thus, the KELT-6 system offers an opportunity to perform a comparative measurement of two similar planets in similar environments around stars of very different metallicities. The precise radial velocity data also reveal an acceleration indicative of a longer-period third body in the system, although the companion is not detected in Keck adaptive optics images.Comment: Published in AJ, 17 pages, 15 figures, 6 table

    Long-term ocean and resource dynamics in a hotspot of climate change

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    Unidad de excelencia María de Maeztu CEX2019-000940-MThe abundance, distribution, and size of marine species are linked to temperature and nutrient regimes and are profoundly affected by humans through exploitation and climate change. Yet little is known about long-term historical links between ocean environmental changes and resource abundance to provide context for current and potential future trends and inform conservation and management. We synthesize >4000 years of climate and marine ecosystem dynamics in a Northwest Atlantic region currently undergoing rapid changes, the Gulf of Maine and Scotian Shelf. This period spans the late Holocene cooling and recent warming and includes both Indigenous and European influence. We compare environmental records from instrumental, sedimentary, coral, and mollusk archives with ecological records from fossils, archaeological, historical, and modern data, and integrate future model projections of environmental and ecosystem changes. This multidisciplinary synthesis provides insight into multiple reference points and shifting baselines of environmental and ecosystem conditions, and projects a near-future departure from natural climate variability in 2028 for the Scotian Shelf and 2034 for the Gulf of Maine. Our work helps advancing integrative end-to-end modeling to improve the predictive capacity of ecosystem forecasts with climate change. Our results can be used to adjust marine conservation strategies and network planning and adapt ecosystem-based management with climate change

    Discovery of δ Scuti Pulsations in the Young Hybrid Debris Disk Star HD 156623

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    The bRing robotic observatory network was built to search for circumplanetary material within the transiting Hill sphere of the exoplanet β Pic b across its bright host star β Pic. During the bRing survey of β Pic, it simultaneously monitored the brightnesses of thousands of bright stars in the southern sky (V ; 4–8, δ −30°). In this work, we announce the discovery of δ Scuti pulsations in the A-type star HD 156623 using bRing data. HD 156623 is notable as it is a well-studied young star with a dusty and gas-rich debris disk, previously detected using ALMA. We present the observational results on the pulsation periods and amplitudes for HD 156623, discuss its evolutionary status, and provide further constraints on its nature and age. We find strong evidence of frequency regularity and grouping. We do not find evidence of frequency, amplitude, or phase modulation for any of the frequencies over the course of the observations. We show that HD 156623 is consistent with other hot and highfrequency pre-main sequence and early zero-age main sequence (ZAMS) δ Scutis as predicted by theoretical models and corresponding evolutionary tracks, although we observe that HD 156623 lies hotter than the theoretical blue edge of the classical instability strip. This, coupled with our characterization and Sco–Cen membership analyses, suggests that the star is most likely an outlying ZAMS member of the ∼16 Myr Upper Centaurus-Lupus subgroup of the Sco–Cen associatio

    KELT-6b: A P ~ 7.9 Day Hot Saturn Transiting A Metal-Poor Star With A Long-Period Companion

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    We report the discovery of KELT-6b, a mildly inflated Saturn-mass planet transiting a metal-poor host. The initial transit signal was identified in KELT-North survey data, and the planetary nature of the occulter was established using a combination of follow-up photometry, high-resolution imaging, high-resolution spectroscopy, and precise radial velocity measurements. The fiducial model from a global analysis including constraints from isochrones indicates that the V = 10.38 host star (BD+31 2447) is a mildly evolved, late-F star with T eff = 6102 ± 43 K, log g_\star =4.07_{-0.07}^{+0.04}, and [Fe/H] = -0.28 ± 0.04, with an inferred mass M sstarf = 1.09 ± 0.04 M ☉ and radius R_\star =1.58_{-0.09}^{+0.16} \,R_\odot. The planetary companion has mass MP = 0.43 ± 0.05 M Jup, radius R_{P}=1.19_{-0.08}^{+0.13} \,R_Jup, surface gravity log g_{P}=2.86_{-0.08}^{+0.06}, and density \rho _{P}=0.31_{-0.08}^{+0.07}\,g\,cm^{-3}. The planet is on an orbit with semimajor axis a = 0.079 ± 0.001 AU and eccentricity e=0.22_{-0.10}^{+0.12}, which is roughly consistent with circular, and has ephemeris of T c(BJDTDB) = 2456347.79679 ± 0.00036 and P = 7.845631 ± 0.000046 days. Equally plausible fits that employ empirical constraints on the host-star parameters rather than isochrones yield a larger planet mass and radius by ~4}-7}. KELT-6b has surface gravity and incident flux similar to HD 209458b, but orbits a host that is more metal poor than HD 209458 by ~0.3 dex. Thus, the KELT-6 system offers an opportunity to perform a comparative measurement of two similar planets in similar environments around stars of very different metallicities. The precise radial velocity data also reveal an acceleration indicative of a longer-period third body in the system, although the companion is not detected in Keck adaptive optics images.KELT is a joint project of The Ohio State University, Vanderbilt University, and Lehigh University

    Kelt-4Ab: An inflated hot jupiter transiting the bright (V ∼ 10) component of a hierarchical triple

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    We report the discovery of KELT-4Ab, an inflated, transiting Hot Jupiter orbiting the brightest component of ahierarchical triple stellar system. The host star is an F star with Teff =6206 ± 75 K, log g =4.108 ± 0.014, [Fe/H]= -0.116+0.069+0.065, M∗ = 1.201-0.061+0.067 M⊙, and R∗ = 1.603-0.038+0.039 R⊙. The best-fit linear ephemeris is BJDTDB =2456193.29157±0.00021 + E(2.9895936±0.0000048). With a magnitude of V∼10, a planetary radius of 1.699-0.045+0.046 RJ, and a mass of 0.902-0.059+0.060 MJ, it is the brightest host among the population of inflated Hot Jupiters (RP \u3e 1.5RJ), making it a valuable discovery for probing the nature of inflated planets. In addition, its existence within a hierarchical triple and its proximity to Earth (210 pc) provide a unique opportunity for dynamical studies with continued monitoring with high resolution imaging and precision radial velocities. The projected separation between KELT-4A and KELT-4BC is 328±16 AU and the projected separation between KELT-4B and KELT-4C is 10.30±0.74 AU. Assuming face-on, circular orbits, their respective periods would be 3780±290 and 29.4±3.6 years and the astrometric motions relative to the epoch in this work of both the binary stars around each other and of the binary around the primary star would be detectable now and may provide meaningful constraints on the dynamics of the system

    KELT-4Ab: An Inflated Hot Jupiter Transiting The Bright (V~10) Component Of A Hierarchical Triple

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    We report the discovery of KELT-4Ab, an inflated, transiting Hot Jupiter orbiting the brightest component of a hierarchical triple stellar system. The host star is an F star with Teff{T}_{{\rm{eff}}} = 6206±756206\pm 75 K, logg\mathrm{log}g = 4.108±0.0144.108\pm 0.014, [Fe/H][{\rm{Fe}}/{\rm{H}}] = 0.1160.069+0.065-{0.116}_{-0.069}^{+0.065}, M{M}_{*} = 1.2010.061+0.067{1.201}_{-0.061}^{+0.067}   M\;{M}_{\odot }, and R{R}_{*} = 1.6030.038+0.039{1.603}_{-0.038}^{+0.039}   R\;{R}_{\odot }. The best-fit linear ephemeris is BJDTDB{\mathrm{BJD}}_{\mathrm{TDB}}   =  2456193.29157±0.00021\;=\;2456193.29157\pm 0.00021 +E(2.9895936±0.0000048)\quad +\quad E(2.9895936\pm 0.0000048). With a magnitude of V ~ 10, a planetary radius of 1.6990.045+0.046{1.699}_{-0.045}^{+0.046}   RJ\;{R}_{{\rm{J}}}, and a mass of 0.9020.059+0.060{0.902}_{-0.059}^{+0.060}   MJ\;{M}_{{\rm{J}}}, it is the brightest host among the population of inflated Hot Jupiters (RP \u3e 1.5RJ), making it a valuable discovery for probing the nature of inflated planets. In addition, its existence within a hierarchical triple and its proximity to Earth (210 pc) provide a unique opportunity for dynamical studies with continued monitoring with high resolution imaging and precision radial velocities. The projected separation between KELT-4A and KELT-4BC is 328 ± 16 AU and the projected separation between KELT-4B and KELT-4C is 10.30 ± 0.74 AU. Assuming face-on, circular orbits, their respective periods would be 3780 ± 290 and 29.4 ± 3.6 years and the astrometric motions relative to the epoch in this work of both the binary stars around each other and of the binary around the primary star would be detectable now and may provide meaningful constraints on the dynamics of the system

    KELT-6b: A P ~ 7.9 Day Hot Saturn Transiting a Metal-poor Star with a Long-period Companion

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    We report the discovery of KELT-6b, a mildly inflated Saturn-mass planet transiting a metal-poor host. The initial transit signal was identified in KELT-North survey data, and the planetary nature of the occulter was established using a combination of follow-up photometry, high-resolution imaging, high-resolution spectroscopy, and precise radial velocity measurements. The fiducial model from a global analysis including constraints from isochrones indicates that the V = 10.38 host star (BD+31 2447) is a mildly evolved, late-F star with T eff = 6102 ± 43 K, , and [Fe/H] = –0.28 ± 0.04, with an inferred mass M = 1.09 ± 0.04 M ☉ and radius . The planetary companion has mass MP = 0.43 ± 0.05 M Jup, radius , surface gravity , and density . The planet is on an orbit with semimajor axis a = 0.079 ± 0.001 AU and eccentricity , which is roughly consistent with circular, and has ephemeris of T c(BJDTDB) = 2456347.79679 ± 0.00036 and P = 7.845631 ± 0.000046 days. Equally plausible fits that employ empirical constraints on the host-star parameters rather than isochrones yield a larger planet mass and radius by ~4}-7}. KELT-6b has surface gravity and incident flux similar to HD 209458b, but orbits a host that is more metal poor than HD 209458 by ~0.3 dex. Thus, the KELT-6 system offers an opportunity to perform a comparative measurement of two similar planets in similar environments around stars of very different metallicities. The precise radial velocity data also reveal an acceleration indicative of a longer-period third body in the system, although the companion is not detected in Keck adaptive optics images
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