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Ten days of photometric data were obtained during the commissioning phase of the Kepler mission, including data for the previously known giant transiting exoplanet HAT-P-7b. The data for HAT-P-7b show a smooth rise and fall of light from the planet as it orbits its star, punctuated by a drop of 130 ± 11 parts per million in flux when the planet passes behind its star. We interpret this as the phase variation of the dayside thermal emission plus reflected light from the planet as it orbits its star and is occulted. The depth of the occultation is similar in photometric precision to the detection of a transiting Earth-size planet for which the mission was designed.

Among the solar proxies, κ1 Cet, stands out as potentially having a mass very close to solar and a young age. We report magnetic field measurements and planetary habitability consequences around this star, a proxy of the young Sun when life arose on Earth. Magnetic strength was determined from spectropolarimetric observations and we reconstruct the large-scale surface magnetic field to derive the magnetic environment, stellar winds, and particle flux permeating the interplanetary medium around κ1 Cet. Our results show a closer magnetosphere and mass-loss rate 50 times larger than the current solar wind mass-loss rate when Life arose on Earth, resulting in a larger interaction via space weather disturbances between the stellar wind and a hypothetical young-Earth analogue, potentially affecting the habitability. Interaction of the wind from the young Sun with the planetary ancient magnetic field may have affected the young Earth and its life conditions.

Among the solar proxies, κ 1 Cet, stands out as potentially having a mass very close to solar and a young age. We report magnetic field measurements and planetary habitability consequences around this star, a proxy of the young Sun when life arose on Earth. Magnetic strength was determined from spectropolarimetric observations and we reconstruct the large-scale surface magnetic field to derive the magnetic environment, stellar winds, and particle flux permeating the interplanetary medium around κ 1 Cet. Our results show a closer magnetosphere and mass-loss rate 50 times larger than the current solar wind mass-loss rate when Life arose on Earth, resulting in a larger interaction via space weather disturbances between the stellar wind and a hypothetical young-Earth analogue, potentially affecting the habitability. Interaction of the wind from the young Sun with the planetary ancient magnetic field may have affected the young Earth and its life conditions.

Among the solar proxies,[...]1 Cet, stands out as potentially having a mass very close to solar and a young age. We report magnetic field measurements and planetary habitability consequences around this star, a proxy of the young Sun when life arose on Earth. Magnetic strength was determined from spectropolarimetric observations and we reconstruct the large-scale surface magnetic field to derive the magnetic environment, stellar winds, and particle flux permeating the interplanetary medium around[...]1 Cet. Our results show a closer magnetosphere and mass-loss rate 50 times larger than the current solar wind mass-loss rate when Life arose on Earth, resulting in a larger interaction via space weather disturbances between the stellar wind and a hypothetical young-Earth analogue, potentially affecting the habitability. Interaction of the wind from the young Sun with the planetary ancient magnetic field may have affected the young Earth and its life conditions.

Models of stellar structure and evolution can be constrained using accurate measurements of the parameters of eclipsing binary members of open clusters. Multiple binary stars provide the means to tighten the constraints and, in turn, to improve the precision and accuracy of the age estimate of the host cluster. In the previous two papers of this series, we have demonstrated the use of measurements of multiple eclipsing binaries in the old open cluster NGC6791 to set tighter constraints on the properties of stellar models than was previously possible, thereby improving both the accuracy and precision of the cluster age. We identify and measure the properties of a non-eclipsing cluster member, V56, in NGC\\,6791 and demonstrate how this provides additional model constraints that support and strengthen our previous findings. We analyse multi-epoch spectra of V56 from FLAMES in conjunction with the existing photometry and measurements of eclipsing binaries in NGC6971. The parameters of the V56 components are found to be \\(M_{\\rm p}=1.103\\pm 0.008 M_{\\odot}\\) and \\(M_{\\rm s}=0.974\\pm 0.007 M_{\\odot}\\), \\(R_{\\rm p}=1.764\\pm0.099 R_{\\odot}\\) and \\(R_{\\rm s}=1.045\\pm0.057 R_{\\odot}\\), \\(T_{\\rm eff,p}=5447\\pm125\\) K and \\(T_{\\rm eff,s}=5552\\pm125\\) K, and surface [Fe/H]=\\(+0.29\\pm0.06\\) assuming that they have the same abundance. The derived properties strengthen our previous best estimate of the cluster age of \\(8.3\\pm0.3\\) Gyr and the mass of stars on the lower red giant branch (RGB), which is \\(M_{\\rm RGB} = 1.15\\pm0.02M_{\\odot}\\) for NGC6791. These numbers therefore continue to serve as verification points for other methods of age and mass measures, such as asteroseismology.

We analyze K2 light curves for 132 low-mass (\\(1\\ \\gtrsim\\ M_*\\ \\gtrsim\\ 0.1\\)~\\({M_{\\odot}}\\)) members of the 600--800~Myr-old Hyades cluster and measure rotation periods (\\(P_{rot}\\)) for 116 of these stars. These include 93 stars with no prior \\(P_{rot}\\) measurement; the total number of Hyads with known \\(P_{rot}\\) is now 232. We then combine literature binary data with Gaia DR2 photometry and astrometry to select single star sequences in the Hyades and its roughly coeval Praesepe open cluster, and derive a new reddening value of $A_V = 0.035$$\\pm$$0.011\\( for Praesepe. Comparing the effective temperature--\\)P_{rot}\\( distributions for the Hyades and Praesepe, we find that solar-type Hyads rotate, on average, 0.4~d slower than their Praesepe counterparts. This \\)P_{rot}\\( difference indicates that the Hyades is slightly older than Praesepe: we apply a new gyrochronology model tuned with Praesepe and the Sun, and find an age difference between the two clusters of 57~Myr. However, this \\)P_{rot}$ difference decreases and eventually disappears for lower-mass stars. This provides further evidence for stalling in the rotational evolution of these stars, and highlights the need for more detailed analysis of angular-momentum evolution for stars of different masses and ages.

NGC 3532 is an extremely rich open cluster embedded in the Galactic disc, hitherto lacking a comprehensive, documented membership list. We provide membership probabilities from new radial velocity observations of solar-type and low-mass stars in NGC 3532, in part as a prelude to a subsequent study of stellar rotation in the cluster. Using extant optical and infra-red photometry we constructed a preliminary photometric membership catalogue, consisting of 2230 dwarf and turn-off stars. We selected 1060 of these for observation with the AAOmega spectrograph at the Anglo-Australian Telescope and 391 stars for observations with the Hydra-South spectrograph at the Victor Blanco Telescope, obtaining spectroscopic observations over a decade for 145 stars. We measured radial velocities for our targets through cross-correlation with model spectra and standard stars, and supplemented them with radial velocities for 433 additional stars from the literature. We also measured log g, Teff, and [Fe/H] from the AAOmega spectra. Together with proper motions from Gaia DR2 we find 660 exclusive members. The members are distributed across the whole cluster sequence, from giant stars to M dwarfs, making NGC 3532 one of the richest Galactic open clusters known to date, on par with the Pleiades. From further spectroscopic analysis of 153 dwarf members we find the metallicity to be marginally sub-solar, with [Fe/H]=-0.07. Exploiting trigonometric parallax measurements from Gaia DR2 we find a distance of \\(484^{+35}_{-30}\\) pc. Based on the membership we provide an empirical cluster sequence in multiple photometric passbands. A comparison of the photometry of the measured cluster members with several recent model isochrones enables us to confirm the 300 Myr cluster age. However, all of the models evince departures from the cluster sequence in particular regions, especially in the lower mass range. (abridged)

We present preliminary observational results on tidal synchronization in detached solar-type binary stars in the open clusters M35 (NGC2168; ~ 150 Myr) and M34 (NGC1039; ~ 250 Myr). M35 and M34 provide populations of close late-type binaries with ages that make them attractive observational tests of models of tidal synchronization during the early main-sequence phase. A combined dataset of stellar rotation periods from time-series photometry and binary orbital periods and eccentricities from time-series spectroscopy enables us to determine the angular rotation velocity of the primary star and the orbital angular velocity at periastron. Comparison of the stellar and orbital angular velocities provides information about the level of synchronization in individual binary stars.

We determine the properties of the binary star V106 in the old open cluster NGC6791. We identify the system to be a blue straggler cluster member by using a combination of ground-based and Kepler photometry and multi-epoch spectroscopy. The properties of the primary component are found to be \\(M_{\\rm p}\\sim1.67 \\rm M_{\\odot}\\), more massive than the cluster turn-off, with \\(R_{\\rm p}\\sim1.91 \\rm R_{\\odot}\\) and \\(T_{\\rm eff}=7110\\pm100\\) K. The secondary component is highly oversized and overluminous for its low mass with \\(M_{\\rm s}\\sim0.182 \\rm M_{\\odot}\\), \\(R_{\\rm s}\\sim0.864 \\rm R_{\\odot}\\) and \\(T_{\\rm eff}=6875\\pm200\\) K. We identify this secondary star as a bloated (proto) extremely low-mass helium white dwarf. These properties of V106 suggest that it represents a typical Algol-paradox system and that it evolved through a mass-transfer phase which provides insight into its past evolution. We present a detailed binary stellar evolution model for the formation of V106 using the MESA code and find that the mass-transfer phase only ceased about 40 Myr ago. Due to the short orbital period (P=1.4463 d) another mass-transfer phase is unavoidable once the current primary star evolves towards the red giant phase. We argue that V106 will evolve through a common-envelope phase within the next 100 Myr and merge to become a single over-massive giant. The high mass will make it appear young for its true age, which is revealed by the cluster properties. Therefore, V106 is potentially a prototype progenitor of old field giants masquerading as young.

We report magnetic field measurements for Kappa1~Cet, a proxy of the young Sun when life arose on Earth. We carry out an analysis of the magnetic properties determined from spectropolarimetric observations and reconstruct its large-scale surface magnetic field to derive the magnetic environment, stellar winds and particle flux permeating the interplanetary medium around Kappa1~Cet. Our results show a closer magnetosphere and mass-loss rate of Mdot = 9.7 x 10^{-13} Msol/yr, i.e., a factor 50 times larger than the current solar wind mass-loss rate, resulting in a larger interaction via space weather disturbances between the stellar wind and a hypothetical young-Earth analogue, potentially affecting the planet's habitability. Interaction of the wind from the young Sun with the planetary ancient magnetic field may have affected the young Earth and its life conditions