Taking advantage of the Gaia DR1, we combined TGAS parallaxes with the Tycho-2 and APASS photometry to calculate the star formation history (SFH) of the solar neighbourhood within 250 pc using the colour-magnitude diagram fitting technique. Our dynamically-evolved SFH is in excellent agreement with that calculated from the Hipparcos catalogue within 80 pc of the Sun, showing an enhanced star formation rate (SFR) in the past ~4 Gyr. We then correct the SFR for the disc thickening with age to obtain a SFR that is representative of the whole solar cylinder, and show that even with an extreme correction our results are not consistent with an exponentially decreasing SFR as found by recent studies. Finally, we discuss how this technique can be applied out to ~5 kpc thanks to the next Gaia data releases, which will allow us to quantify the SFH of the thin disc, thick disc and halo in situ.

We took advantage of the Gaia DR1 to combine TGAS parallaxes with Tycho-2 and APASS photometry to calculate the star formation history (SFH) of the solar neighbourhood within 250 pc using the colour-magnitude diagram fitting technique. We present the determination of the completeness within this volume, and compare the resulting SFH with that calculated from the Hipparcos catalogue within 80 pc of the Sun. We also show how this technique will be applied out to ~5 kpc thanks to the next Gaia data releases, which will allow us to quantify the SFH of the thin disc, thick disc and halo in situ, rather than extrapolating based on the stars from these components that are today in the solar neighbourhood.

We use 63,774 F/G dwarf stars from the LAMOST pilot survey to explore the velocity distribution in the solar neighborhood. The intrinsic UV distribution is reconstructed with a 20-Gaussian model using extreme deconvolution. We find at least two arcs, one extending from (−106, −3) to (94, −27) km/s and the other from (29, −9) to (78, −51) km/s. The arcs are qualitatively consistent with numerical simulations of the resonance induced by the Galactic bar and can be used to constrain its dynamical properties.

Rotation is a fundamental physical parameter in stellar astrophysics, playing an important role on the formation and evolution of stars. This parameter may also offer valuable information on stellar magnetism, mixing in the stellar interior, tidal interactions in close binary, as well as on angular momentum transfer and rotational breaking due to planets. The present work brings the results of an unprecedented study on the behavior of the distribution of the projected rotational velocity (v sin i) as a function of galactic position, on the basis of an unique sample of 14000 main-sequence field stars, along the spectral regions F and G. The vsini measurements used in this analyses were obtained from observations carried out with the CORAVEL spectrometers, with a precision better than about 1 km/s.