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We analyse the anisotropic clustering of massive galaxies from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 9 (DR9) sample, which consists of 264 283 galaxies in the redshift range 0.43 < z < 0.7 spanning 3275 deg2. Both peculiar velocities and errors in the assumed redshift-distance relation ('Alcock-Paczynski effect') generate correlations between clustering amplitude and orientation with respect to the line of sight. Together with the sharp baryon acoustic oscillation (BAO) standard ruler, our measurements of the broad-band shape of the monopole and quadrupole correlation functions simultaneously constrain the comoving angular diameter distance (2190 ± 61 Mpc) to z = 0.57, the Hubble expansion rate at z = 0.57 (92.4 ± 4.5 km s-1 Mpc-1) and the growth rate of structure at that same redshift (dsigma8/d ln a = 0.43 ± 0.069). Our analysis provides the best current direct determination of both DA and H in galaxy clustering data using this technique. If we further assume a Lambdacold dark matter expansion history, our growth constraint tightens to dsigma8/d ln a = 0.415 ± 0.034. In combination with the cosmic microwave background, our measurements of DA, H and dsigma8/d ln a all separately require dark energy at z > 0.57, and when combined imply OmegaLambda = 0.74 ± 0.016, independent of the Universe's evolution at z < 0.57. All of these constraints assume scale-independent linear growth, and assume general relativity to compute both O(10 per cent) non-linear model corrections and our errors. In our companion paper, Samushia et al., we explore further cosmological implications of these observations.

We present an eccentric, short-period brown dwarf candidate orbiting the active, slightly evolved subgiant star TYC 2087-00255-1, which has effective temperature Teff = 5903±42 K, surface gravity log(g) = 4.07±0.16 (cgs), and metallicity [Fe/H] = −0.23 ± 0.07. This candidate was discovered using data from the first two years of the Multi-object APO Radial Velocity Exoplanets Large-area Survey, which is part of the third phase of Sloan Digital Sky Survey. From our 38 radial velocity measurements spread over a two-year time baseline, we derive a Keplerian orbital fit with semi-amplitude K = 3.571 ± 0.041 km s−1, period P = 9.0090 ± 0.0004 days, and eccentricity e = 0.226±0.011. Adopting a mass of 1.16±0.11M for the subgiant host star, we infer that the companion has a minimum mass of 40.0 ± 2.5MJup. Assuming an edge-on orbit, the semimajor axis is 0.090 ± 0.003 AU. The host star is photometrically variable at the ∼1% level with a period of ∼13.16±0.01 days, indicating that the host star spin and companion orbit are not synchronized. Through adaptive optics imaging we also found a point source 643 ± 10 mas away from TYC 2087-00255-1, which would have a mass of 0.13M if it is physically associated with TYC 2087-00255-1 and has the same age. Future proper motion observation should be able to resolve if this tertiary object is physically associated with TYC 2087-00255-1 and make TYC 2087-00255-1 a triple body system. Core Ca ii H and K line emission indicate that the host is chromospherically active, at a level that is consistent with the inferred spin period and measured vrot sin i, but unusual for a subgiant of this Teff . This activity could be explained by ongoing tidal spin-up of the host star by the companion.

We report the discovery of a candidate brown dwarf (BD) or a very low mass stellar companion (MARVELS-5b) to the star HIP 67526 from the Multi-object Apache point observatory Radial Velocity Exoplanet Large-area Survey (MARVELS). The radial velocity curve for this object contains 31 epochs spread over 2.5 yr.OurKeplerian fit, using a Markov Chain Monte Carlo approach, reveals that the companion has an orbital period of 90.2695+0.0188 −0.0187 days, an eccentricity of 0.4375±0.0040, and a semi-amplitude of 2948.14+16.65 −16.55 m s−1. Using additional high-resolution spectroscopy, we find the host star has an effective temperature Teff = 6004 ± 34 K, a surface gravity log g (cgs) = 4.55 ± 0.17, and a metallicity [Fe/H] = +0.04 ± 0.06. The stellar mass and radius determined through the empirical relationship of Torres et al. yields 1.10±0.09M and 0.92±0.19R . The minimummass ofMARVELS- 5b is 65.0±2.9MJup, indicating that it is likely to be either a BD or a very low mass star, thus occupying a relatively sparsely populated region of the mass function of companions to solar-type stars. The distance to this system is 101 ± 10 pc from the astrometric measurements of Hipparcos. No stellar tertiary is detected in the high-contrast images taken by either FastCam lucky imaging or Keck adaptive optics imaging, ruling out any star with mass greater than 0.2 M at a separation larger than 40 AU.

TYC 4110-01037-1 has a low-mass stellar companion, whose small mass ratio and short orbital period are atypical among binary systems with solar-like (Teff 6000 K) primary stars. Our analysis of TYC 4110-01037-1 reveals it to be a moderately aged ( 5 Gyr) solar-like star having a mass of 1.07 ± 0.08M and radius of 0.99 ± 0.18 R . We analyze 32 radial velocity (RV) measurements from the SDSS-III MARVELS survey as well as 6 supporting RV measurements from the SARG spectrograph on the 3.6 m Telescopio Nazionale Galileo telescope obtained over a period of ∼2 years. The best Keplerian orbital fit parameters were found to have a period of 78.994 ± 0.012 days, an eccentricity of 0.1095 ± 0.0023, and a semi-amplitude of 4199 ± 11 m s−1. We determine the minimum companion mass (if sin i = 1) to be 97.7 ± 5.8 MJup. The system’s companion to host star mass ratio, 0.087 ± 0.003, places it at the lowest end of observed values for short period stellar companions to solar-like (Teff 6000 K) stars. One possible way to create such a system would be if a triple-component stellar multiple broke up into a short period, low q binary during the cluster dispersal phase of its lifetime. A candidate tertiary body has been identified in the system via single-epoch, high contrast imagery. If this object is confirmed to be comoving, we estimate it would be a dM4 star. We present these results in the context of our larger-scale effort to constrain the statistics of low-mass stellar and brown dwarf companions to FGK-type stars via the MARVELS survey.