| 1. |
- Alsubai, Khalid, et al.
(author)
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Qatar Exoplanet Survey : Qatar-3b, Qatar-4b, and Qatar-5b
- 2017
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In: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 153:4
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Journal article (peer-reviewed)abstract
- We report the discovery of Qatar-3b, Qatar-4b, and Qatar-5b, three new transiting planets identified by the Qatar Exoplanet Survey. The three planets belong to the hot Jupiter family, with orbital periods of P-Q3b = 2.50792 days, P-Q4b = 1.80539 days, and P-Q5b = 2.87923 days. Follow-up spectroscopic observations reveal the masses of the planets to be M-Q3b = 4.31 +/- 0.47 M-J, M-Q4b = 6.10 +/- 0.54 M-J, and M-Q5b = 4.32 +/- 0.18 M-J, while model fits to the transit light curves yield radii of R-Q3b = 1.096 +/- 0.14 RJ, R-Q4b = 1.135 +/- 0.11 R-J, and R-Q5b = 1.107 +/- 0.064 R-J. The host stars are low-mass main sequence stars with masses and radii M-Q3 = 1.145 +/- 0.064 M circle dot, M-Q4 = 0.896 +/- 0.048 M circle dot, M-Q5 = 1.128 +/- 0.056 M circle dot and R-Q3 = 1.272 +/- 0.14 R circle dot, R-Q4 = 0.849 +/- 0.063 R circle dot, and R-Q5 = 1.076 +/- 0.051 R circle dot for Qatar-3, 4, and 5 respectively. The V magnitudes of the three host stars are V-Q3 = 12.88, V-Q4 = 13.60, and V-Q5 = 12.82. All three new planets can be classified as heavy hot Jupiters (M > 4 M-J).
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| 2. |
- Hey, Daniel R., et al.
(author)
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Parameters of the eclipsing binary alpha Draconis observed by TESS and SONG
- 2022
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In: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 511:2, s. 2648-2658
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Journal article (peer-reviewed)abstract
- We present an analysis of the eclipsing single-lined spectroscopic binary system a Dra based on photometry from the Transiting Exoplanet Survey Satellite (TESS) mission and newly acquired spectroscopic measurements. Recently discovered to have eclipses in the TESS data, at a magnitude of V = 3.7, alpha Dra is now one of the brightest detached eclipsing binary (EB) systems known. We obtain the parameters of this system by simultaneously fitting the TESS light curve in conjunction with radial velocities (RVs) acquired from the SONG spectrograph. We determine the fractional radii (Rla) for the primary and secondary components of the system to be 0.0479 +/- 0.0003 and 0.0226 +/- 0.0005, respectively. We constrain the temperature, mass, and luminosity (log(L/L-circle dot)) of the primary to be 9975 +/- 125 K, 3.7 +/- 0.1 M-circle dot, and 2.49 +/- 0.02, respectively, using isochrone fitting. Although the secondary is too faint to appear in the spectra, the obtained mass function and observed inclination yields a secondary minimum mass of M-2 = 2.5 +/- 0.1 M-circle dot, which suggests that it is an A2V type star. We were unable to obtain RVs of the secondary, and are only able to see a weak highly rotationally broadened absorption line, indicating that the secondary is rapidly rotating (vsin i similar to 200 km s(-1)). We also perform an abundance analysis of the primary star for 21 chemical elements. We find a complex abundance pattern, with a few elements having mild underabundances while the majority have solar abundances. We make available the PYTHON code used in this paper to facilitate future modelling of EBs. https://github.com/danhey/adra
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| 3. |
- Olsson, Anders, 1940-, et al.
(author)
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Effects of rosuvastatin and atorvastatin compared over 52 weeks of treatment in patients with hypercholesterolemia
- 2002
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In: American Heart Journal. - : Elsevier BV. - 0002-8703 .- 1097-6744. ; 144:6, s. 1044-1051
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Journal article (peer-reviewed)abstract
- Background: Despite the demonstrated benefits of low-density lipoprotein cholesterol (LDL-C) reduction in reducing the risk of coronary heart disease, many patients receiving lipid-lowering therapy fail to achieve LDL-C goals. We compared the effects of rosuvastatin and atorvastatin in reducing LDL-C and achieving LDL-C goals in patients with primary hypercholesterolemia. Methods and Results: In this 52-week, randomized, double-blind, multicenter trial (4522IL/0026), 412 patients with LDL-C 160 to <250 mg/dL received a 5-mg dose of rosuvastatin (n = 138), a 10-mg dose of rosuvastatin (n = 134), or a 10-mg dose of atorvastatin (n = 140) for 12 weeks, during the following 40 weeks, dosages could be sequentially doubled up to 80 mg if National Cholesterol Education Program Adult Treatment Panel II (ATP-II) LDL-C goals were not achieved. At 12 weeks, 5- and 10-mg doses of rosuvastatin were associated with significantly greater LDL-C reductions than 10-mg doses of atorvastatin (46% and 50% vs 39%, both P < .001). At 12 weeks, both rosuvastatin dosages brought more patients to within ATP-II and European LDL-C goals than atorvastatin (86% and 89% vs 73% and 75%, and 86% vs 55%, respectively). At 52 weeks, compared with atorvastatin, both initial rosuvastatin treatment groups significantly reduced LDL-C (47% and 53% vs 44%, P < .05 and P < .001). Overall, more patients in the initial rosuvastatin 10-mg group achieved their ATP-II LDL-C goal than those in the initial atorvastatin 10-mg group (98% vs 87%), with 82% of patients treated with rosuvastatin achieving their goal at the 10-mg starting dosage without the need for titration, compared with 59% of patients treated with atorvastatin. Both treatments were well tolerated over 52 weeks. Conclusion: Compared with atorvastatin, rosuvastatin produced greater reductions in LDL-C, which may offer advantages in LDL-C goal attainment over existing lipid-lowering therapies.
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| 4. |
- Shvartzvald, Yossi, et al.
(author)
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Spitzer Microlensing Parallax for OGLE-2017-BLG-0896 Reveals a Counter-rotating Low-mass Brown Dwarf
- 2019
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In: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 157:3
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Journal article (peer-reviewed)abstract
- The kinematics of isolated brown dwarfs in the Galaxy, beyond the solar neighborhood, is virtually unknown. Microlensing has the potential to probe this hidden population, as it can measure both the mass and five of the six phase-space coordinates (all except the radial velocity) even of a dark isolated lens. However, the measurements of both the microlens-parallax and finite-source effects are needed in order to recover the full information. Here, we combine the Spitzer satellite parallax measurement with the ground-based light curve, which exhibits strong finite-source effects, of event OGLE-2017-BLG-0896. We find two degenerate solutions for the lens (due to the known satellite-parallax degeneracy), which are consistent with each other except for their proper motion. The lens is an isolated brown dwarf with a mass of either 18 +/- 1 M-J or 20 +/- 1 M-J. This is the lowest isolated-object mass measurement to date, only similar to 45% more massive than the theoretical deuterium-fusion boundary at solar metallicity, which is the common definition of a free-floating planet. The brown dwarf is located at either 3.9 +/- 0.1 kpc or 4.1 +/- 0.1 kpc toward the Galactic bulge, but with proper motion in the opposite direction of disk stars, with one solution suggesting it is moving within the Galactic plane. While it is possibly a halo brown dwarf, it might also represent a different, unknown population.
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| 5. |
- Southworth, John, et al.
(author)
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Detection of the Atmosphere of the 1.6 M-circle plus Exoplanet GJ 1132 b
- 2017
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In: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 153:4
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Journal article (peer-reviewed)abstract
- Detecting the atmospheres of low-mass, low-temperature exoplanets is a high-priority goal on the path to ultimately detecting biosignatures in the atmospheres of habitable exoplanets. High-precision HST observations of several super-Earths with equilibrium temperatures below 1000 K have to date all resulted in featureless transmission spectra, which have been suggested to be due to high-altitude clouds. We report the detection of an atmospheric feature in the atmosphere of a 1.6 M-circle plus transiting exoplanet, GJ 1132 b, with an equilibrium temperature of similar to 600 K and orbiting a nearby M dwarf. We present observations of nine transits of the planet obtained simultaneously in the griz and JHK passbands. We find an average radius of 1.43 +/- 0.16 R-circle plus for the planet, averaged over all the passbands, and a radius of 0.255 +/- 0.023 R-circle dot for the star, both of which are significantly greater than previously found. The planet radius can be decomposed into a surface radius at similar to 1.375 R-circle plus overlaid by atmospheric features that increase the observed radius in the z and K bands. The z-band radius is 4 sigma higher than the continuum, suggesting a strong detection of an atmosphere. We deploy a suite of tests to verify the reliability of the transmission spectrum, which are greatly helped by the existence of repeat observations. The large z-band transit depth indicates strong opacity from H2O and/or CH4 or a hitherto-unconsidered opacity. A surface radius of 1.375 +/- 0.16 R-circle plus allows for a wide range of interior compositions ranging from a nearly Earth-like rocky interior, with similar to 70% silicate and similar to 30% Fe, to a substantially H2O-rich water world.
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