198 research outputs found

    Discovery of the Transiting Planet Kepler-5B

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    We present 44 days of high duty cycle, ultra precise photometry of the 13th magnitude star Kepler-5 (KIC 8191672, T(eff) = 6300 K, log g = 4.1), which exhibits periodic transits with a depth of 0.7%. Detailed modeling of the transit is consistent with a planetary companion with an orbital period of 3.548460 +/- 0.000032 days and a radius of 1.431(-0.052)(+0.041) R(J). Follow-up radial velocity measurements with the Keck HIRES spectrograph on nine separate nights demonstrate that the planet is more than twice as massive as Jupiter with a mass of 2.114(-0.059)(+0.056) M(J) and a mean density of 0.894 +/- 0.079 g cm(-3).NASA's Science Mission DirectorateAstronom

    Kepler-7b: A Transiting Planet with Unusually Low Density

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    We report the discovery and confirmation of Kepler-7b, a transiting planet with unusually low density. The mass is less than half that of Jupiter, Mp = 0.43 Mj, but the radius is fifty percent larger, Rp = 1.48 Rj. The resulting density, 0.17 g/cc, is the second lowest reported so far for an extrasolar planet. The orbital period is fairly long, P = 4.886 days, and the host star is not much hotter than the Sun, Teff = 6000 K. However, it is more massive and considerably larger than the sun, Mstar = 1.35 Msun and Rstar = 1.84 Rsun, and must be near the end of its life on the Main Sequence.Comment: 19 pages, 3 figure

    The Interactions of Change in Nutrition on Uterine Environment and Cholesterol Concentrations in Beef Cattle

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    The objective of this study was to evaluate the impact of nutritional changes prior to and after artificial insemination (AI) on uterine environment and plasma cholesterol concentrations

    A Transiting Hot Jupiter Orbiting a Metal-Rich Star

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    We announce the discovery of Kepler-6b, a transiting hot Jupiter orbiting a star with unusually high metallicity, [Fe/H] = +0.34 +/- 0.04. The planet's mass is about 2/3 that of Jupiter, Mp = 0.67 Mj, and the radius is thirty percent larger than that of Jupiter, Rp = 1.32 Rj, resulting in a density of 0.35 g/cc, a fairly typical value for such a planet. The orbital period is P = 3.235 days. The host star is both more massive than the Sun, Mstar = 1.21 Msun, and larger than the Sun, Rstar = 1.39 Rsun.Comment: 12 pages, 2 figures, submitted to the Astrophysical Journal Letter

    Use of Sperm In Vitro Capacitation and Flow Cytometry to Estimate Bull Fertility

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    Study Description: Frozen-thawed semen from five bulls previously identified as high (48.1% and 47.7%, bulls A and B, respectively), intermediary (45.5%, bull C) or low (43.1% and 40.7%, bulls D and E, respectively) fertility, based on pregnancy per AI, were evaluated with several laboratory measures. Measures included total motility, sperm plasma membrane integrity (viability), acrosome integrity, reactive oxygen species (ROS), mitochondrial membrane energy potential (mito-potential), zinc signatures (signatures 1 to 4), and CD9 protein populations at pre-wash, post-wash, h 0 (diluted with non-capacitation media), and at 0, 3, 6, and 24 h after dilution with capacitation media and incubation at 37 ºC. Data were analyzed using the GLIMMIX procedure of SAS for repeated measures with bull, time, and the interaction as fixed effects. Bull by time interaction was significant (P ≤ 0.01) for total motility and viability. There tended (P = 0.06) to be a bull by time interaction for zinc signatures 1 + 2 combined. There was a significant effect of bull (P ≤ 0.03) for viability, viable sperm with disrupted acrosome, zinc signatures 1, 2, and 1 + 2, viable CD9- (CD9 negative), and dead CD9+ (CD9 positive). High and intermediary field fertility bulls had greater (P ≤ 0.04) percentages of viable sperm, zinc signature 2, and zinc signature 1 + 2 compared to low fertility bulls. High and intermediary fertility bulls had decreased (P ≤ 0.05) percentage of dead CD9+ compared to low fertility bulls. There was or tended to be a positive correlation between pregnancy per AI and viability (P = 0.10; r = 0.81), zinc signature 2 (P = 0.04; r = 0.89), and zinc signature 1 + 2 (P = 0.10; r = 0.80)

    Interactions of Change in Nutrition After AI on Plasma Metabolites, Steroid Hormone Production, and Uterine Environment

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    Objective The objective was to evaluate the impact of nutritional changes post artificial insemination (AI) on plasma metabolites, steroid hormones, and uterine environment. Study Description Beef heifers (n = 43) were randomly assigned to two dietary treatment groups (High = 161.5% or Low = 77.5% of maintenance energy) for 14 d after AI (post-AI). Post-AI dietary treatments continued until uteri were flushed for embryo recovery (d 14 post-AI). Blood samples were collected on d -3, 0 (day of AI), 3, 6, 9, 12, and 14 for analysis of plasma glucose, proteins, non-esterified fatty acids (NEFAs), and cholesterol using colorimetric assays. Plasma collected on d 0, 3, 6, 9, 12, and 14 was analyzed for progesterone concentrations by radioimmunoassay. Uterine flushes were analyzed for mineral concentrations of Mg, P, S, K, Ca, Cu, Zn, Se, Mn, Co, B, Cr, and Fe by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Plasma progesterone, NEFAs, protein, glucose and cholesterol (repeated measures) and uterine mineral concentrations were analyzed using the MIXED procedures in SAS. Plasma NEFA concentrations differed between treatments (P = 0.03) with heifers on the low diet treatment having elevated NEFA concentrations. Plasma NEFA concentrations weren’t affected by embryo recovery (P \u3e 0.10), treatment by embryo recovery (P \u3e 0.10), and treatment by embryo recovery by day (P \u3e 0.10). Plasma progesterone, glucose, protein, and cholesterol concentrations were not influenced by treatment (P \u3e 0.10), embryo recovery (P \u3e 0.10), treatment by embryo recovery (P \u3e 0.10), and treatment by embryo recovery by day (P \u3e 0.10). Uterine mineral concentrations were affected by embryo presence for Mg (P = 0.02) and S (P = 0.01) a tendency for Ca (P = 0.08) with decreased concentrations in uterine flushes when an embryo was recovered. A tendency for increased concentration of Mn (P = 0.06) was observed in uterine flushes when an embryo was recovered. Additionally, treatment tended to impact Fe concentrations (P = 0.09), with heifers on the restricted diet having reduced uterine Fe concentrations. In conclusion, changing plane of nutrition post-AI had an effect on NEFA plasma concentrations, but no effect on plasma progesterone, protein, glucose, and cholesterol concentrations. The presence of an embryo however affected uterine mineral concentrations

    A First Comparison of Kepler Planet Candidates in Single and Multiple Systems

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    In this letter we present an overview of the rich population of systems with multiple candidate transiting planets found in the first four months of Kepler data. The census of multiples includes 115 targets that show 2 candidate planets, 45 with 3, 8 with 4, and 1 each with 5 and 6, for a total of 170 systems with 408 candidates. When compared to the 827 systems with only one candidate, the multiples account for 17 percent of the total number of systems, and a third of all the planet candidates. We compare the characteristics of candidates found in multiples with those found in singles. False positives due to eclipsing binaries are much less common for the multiples, as expected. Singles and multiples are both dominated by planets smaller than Neptune; 69 +2/-3 percent for singles and 86 +2/-5 percent for multiples. This result, that systems with multiple transiting planets are less likely to include a transiting giant planet, suggests that close-in giant planets tend to disrupt the orbital inclinations of small planets in flat systems, or maybe even to prevent the formation of such systems in the first place.Comment: 13 pages, 13 figures, submitted to ApJ Letter

    Validation of Kepler's Multiple Planet Candidates. III: Light Curve Analysis & Announcement of Hundreds of New Multi-planet Systems

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    The Kepler mission has discovered over 2500 exoplanet candidates in the first two years of spacecraft data, with approximately 40% of them in candidate multi-planet systems. The high rate of multiplicity combined with the low rate of identified false-positives indicates that the multiplanet systems contain very few false-positive signals due to other systems not gravitationally bound to the target star (Lissauer, J. J., et al., 2012, ApJ 750, 131). False positives in the multi- planet systems are identified and removed, leaving behind a residual population of candidate multi-planet transiting systems expected to have a false-positive rate less than 1%. We present a sample of 340 planetary systems that contain 851 planets that are validated to substantially better than the 99% confidence level; the vast majority of these have not been previously verified as planets. We expect ~2 unidentified false-positives making our sample of planet very reliable. We present fundamental planetary properties of our sample based on a comprehensive analysis of Kepler light curves and ground-based spectroscopy and high-resolution imaging. Since we do not require spectroscopy or high-resolution imaging for validation, some of our derived parameters for a planetary system may be systematically incorrect due to dilution from light due to additional stars in the photometric aperture. None the less, our result nearly doubles the number of verified exoplanets.Comment: 138 pages, 8 Figures, 5 Tables. Accepted for publications in the Astrophysical Journa
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