HATNet Field G205: Follow-Up Observations of 28 Transiting-Planet candidates and Confirmation of the Planet HAT-P-8b

We report the identification of 32 transiting-planet candidates in HATNet field G205. We describe the procedures that we have used to follow up these candidates with spectroscopic and photometric observations, and we present a status report on our interpretation of the 28 candidates for which we have follow-up observations. Eight are eclipsing binaries with orbital solutions whose periods are consistent with their photometric ephemerides; two of these spectroscopic orbits are singled-lined and six are double-lined. For one of the candidates, a nearby but fainter eclipsing binary proved to be the source for the HATNet light curve, due to blending in the HATNet images. Four of the candidates were found to be rotating more rapidly than vsini = 50 km/s and were not pursued further. Thirteen of the candidates showed no significant velocity variation at the level of 0.5 to 1.0 km/s . Seven of these were eventually withdrawn as photometric false alarms based on an independent reanalysis using more sophisticated tools. Of the remaining six, one was put aside because a close visual companion proved to be a spectroscopic binary, and two were not followed up because the host stars were judged to be too large. Two of the remaining candidates are members of a visual binary, one of which was previously confirmed as the first HATNet transiting planet, HAT-P-1b. In this paper we confirm that the last of this set of candidates is also a a transiting planet, which we designate HAT-P-8b, with mass Mp = 1.52 +/- 0.18/0.16 Mjup, radius Rp = 1.50 +/- 0.08/0.06 Rjup, and photometric period P = 3.076320 +/- 0.000004 days. HAT-P-8b has an inflated radius for its mass, and a large mass for its period. The host star is a solar-metallicity F dwarf, with mass M* = 1.28 +/- 0.04 Msun and Rp = 1.58 +/- 0.08/0.06 Rsun.Comment: 16 pages, 6 figures, 13 table

The N2K Consortium. III. Short-Period Planets Orbiting HD 149143 and HD 109749

We report the detection of two short-period planets discovered at Keck Observatory. HD 149143 is a metal-rich G0 IV star with a planet of M sin i = 1.33M_J and an orbital radius of 0.053 AU. The best-fit Keplerian model has an orbital period, P = 4.072 days, semivelocity amplitude, K = 149.6 m s^(-1), and eccentricity, e = 0.016 ± 0.01. The host star is chromospherically inactive and metal-rich, with [Fe/H] = 0.26. Based on the T_(eff) and stellar luminosity, we derive a stellar radius of 1.49 R_☉. Photometric observations of HD 149143 were carried out using the automated photometric telescopes at Fairborn Observatory. HD 149143 is photometrically constant over the radial velocity period to 0.0003 ± 0.0002 mag, supporting the existence of the planetary companion. No transits were detected down to a photometric limit of approximately 0.02%, eliminating transiting planets with a variety of compositions and constraining the orbital inclination to less than 83°. A short-period planet was also detected around HD 109749, a G3 IV star. HD 109749 is chromospherically inactive, with [Fe/H] = 0.25 and a stellar radius of 1.24. The radial velocities for HD 109749 are modeled by a Keplerian with P = 5.24 days and K = 28.7 m s^(-1). The inferred planet mass is M sin i = 0.28M_J and the semimajor axis of this orbit is 0.0635 AU. Photometry of HD 109749 was obtained with the SMARTS consortium telescope, the PROMPT telescope, and by transitsearch.org observers in Adelaide and Pretoria. These observations did not detect a decrement in the brightness of the host star at the predicted ephemeris time, and they constrain the orbital inclination to less than 85° for gas giant planets with radii down to 0.7R_J

The Mass of KOI-94d and a Relation for Planet Radius, Mass, and Incident Flux

We measure the mass of a modestly irradiated giant planet, KOI-94d. We wish to determine whether this planet, which is in a 22 day orbit and receives 2700 times as much incident flux as Jupiter, is as dense as Jupiter or rarefied like inflated hot Jupiters. KOI-94 also hosts at least three smaller transiting planets, all of which were detected by the Kepler mission. With 26 radial velocities of KOI-94 from the W. M. Keck Observatory and a simultaneous fit to the Kepler light curve, we measure the mass of the giant planet and determine that it is not inflated. Support for the planetary interpretation of the other three candidates comes from gravitational interactions through transit timing variations, the statistical robustness of multi-planet systems against false positives, and several lines of evidence that no other star resides within the photometric aperture. We report the properties of KOI-94b (M_P = 10.5 ± 4.6 M_⊕, R_P = 1.71 ± 0.16 R_⊕, P = 3.74 days), KOI-94c (M_P = 15.6^(+5.7)_(-15.6) M_⊕, R_P = 4.32 ± 0.41 R_⊕, P = 10.4 days), KOI-94d (M_P = 106 ± 11 M_⊕, R_P = 11.27 ± 1.06 R_⊕, P = 22.3 days), and KOI-94e (M_P = 35^(+18)_(-28) M_⊕, R_P = 6.56 ± 0.62 R_⊕, P = 54.3 days). The radial velocity analyses of KOI-94b and KOI-94e offer marginal (>2σ) mass detections, whereas the observations of KOI-94c offer only an upper limit to its mass. Using the KOI-94 system and other planets with published values for both mass and radius (138 exoplanets total, including 35 with M_P 150 M_⊕. These equations can be used to predict the radius or mass of a planet

Werther

Johann Wolfgang Goethe'nin Malumat'ta yayımlanan Werther adlı romanının ilk ve son tefrikalarıTefrikanın devamına rastlanmamış, tefrika yarım kalmıştır