We present the result of calculations to optimize the search for molecular oxygen, O-2, in Earth analogs transiting around nearby, low-mass stars using ground-based, high-resolution Doppler shift techniques. We investigate a series of parameters, namely spectral resolution, wavelength coverage of the observations, and sky coordinates and systemic velocity of the exoplanetary systems, to find the values that optimize detectability of O-2. We find that increasing the spectral resolution of observations to R similar to 300,000-400,000 from the typical R similar to 100,000 more than doubles the average depth of O-2 lines in planets with atmospheres similar to Earth's. Resolutions higher than similar to 500,000 do not produce significant gains in the depths of the O-2 lines. We confirm that observations in the O-2 A-band are the most efficient except for M9V host stars, for which observations in the O-2 near-infrared (NIR) band are more efficient. Combining observations in the O-2 A, B, and NIR bands can reduce the number of transits needed to produce a detection of O-2 by about one-third in the case of white noise limited observations. However, that advantage disappears in the presence of typical levels of red noise. Therefore, combining observations in more than one band produces no significant gain versus observing only in the A band, unless red noise can be significantly reduced. Blending between the exoplanet's O-2 lines and telluric O-2 lines is a known problem. We find that problem can be alleviated by increasing the resolution of the observations, and by giving preference to targets near the ecliptic.

We have discovered a wide planetary-mass companion to the beta Pic moving group member 2MASS J02495639-0557352 (M6 VL G) using Canada-France-Hawaii Telescope/WIRCam astrometry from the Hawaii Infrared Parallax Program. In addition, Keck laser guide star adaptive optics aperture-masking interferometry shows that the host is itself a tight binary. Altogether, 2MASS J0249-0557ABc is a bound triple system with an 11.6(-1.0)(+1.3) M-Jup object separated by 1950 +/- 200 au (40 '') from a relatively close (2.17 +/- 0.22 au, 0.'' 04) pair of 48(-12)(+13) M(Jup )and 44(-11)(+14) M-Jup objects. 2MASS J0249-0557AB is one of the few ultracool binaries to be discovered in a young moving group and the first confirmed in the beta Pic moving group (22 +/- 6 Myr). The mass, absolute magnitudes, and spectral type of 2MASS J0249-0557 c (L2 VL G) are remarkably similar to those of the planet beta Pic b (L2, 13.0(-0.3)(+0.4)M(Jup)). We also find that the free-floating object 2MASS J2208+2921 (L3 VL-G) is another possible & nbsp;beta Pic moving group member with colors and absolute magnitudes similar to beta Pic b and 2MASS J0249-0557 c. beta Pic b is the first directly imaged planet to have a "twin," namely an object of comparable properties in the same stellar association. Such directly imaged objects provide a unique opportunity to measure atmospheric composition, variability, and rotation across different pathways of assembling planetary-mass objects from the same natal material.

The Kepler survey provides a statistical census of planetary systems out to the habitable zone. Because most planets are non-transiting, orbital architectures are best estimated using simulated observations of ensemble populations. Here, we introduce EPOS, the Exoplanet Population Observation Simulator, to estimate the prevalence and orbital architectures of multi-planet systems based on the latest Kepler data release, DR25. We estimate that at least 42% of Sun-like stars have nearly coplanar planetary systems with seven or more exoplanets. The fraction of stars with at least one planet within 1 au could be as high as 100% depending on assumptions about the distribution of single transiting planets. We estimate an occurrence rate of planets in the habitable zone around Sun-like stars of eta(circle plus) - 36 +/- 14%. The innermost planets in multi-planet systems are clustered around an orbital period of 10 days (0.1 au), reminiscent of the protoplanetary disk inner edge, or which could be explained by a planet trap at that location. Only a small fraction of planetary systems have the innermost planet at long orbital periods, with fewer than approximate to 8% and approximate to 3% having no planet interior to the orbit of Mercury and Venus, respectively. These results reinforce the view that the solar system is not a typical planetary system, but an outlier among the distribution of known exoplanetary systems. We predict that at least half of the habitable zone exoplanets are accompanied by (non-transiting) planets at shorter orbital periods, hence knowledge of a close-in exoplanet could be used as a way to optimize the search for Earth-size planets in the Habitable Zone with future direct imaging missions.

Binary stars make up a significant portion of all stellar systems. Consequently, an understanding of the bulk properties of binary stars is necessary for a full picture of star formation. Binary surveys indicate that both multiplicity fraction and typical orbital separation increase as functions of primary mass. Correlations with higher-order architectural parameters such as mass ratio are less well constrained. We seek to identify and characterize double-lined spectroscopic binaries (SB2s) among the 1350 M-dwarf ancillary science targets with APOGEE spectra in the SDSS-III Data Release 13. We measure the degree of asymmetry in the APOGEE pipeline crosscorrelation functions (CCFs) and use those metrics to identify a sample of 44 high-likelihood candidate SB2s. At least 11 of these SB2s are known, having been previously identified by Deshpande et al. and/or El-Badry et al. We are able to extract radial velocities (RVs) for the components of 36 of these systems from their CCFs. With these RVs, we measure mass ratios for 29 SB2s and five SB3s. We use Bayesian techniques to fit maximum-likelihood (but still preliminary) orbits for four SB2s with eight or more distinct APOGEE observations. The observed (but incomplete) mass-ratio distribution of this sample rises quickly toward unity. Two-sided Kolmogorov-Smirnov tests find probabilities of 18.3% and 18.7%, demonstrating that the mass-ratio distribution of our sample is consistent with those measured by Pourbaix et al. and Fernandez et al., respectively.

We present TURBUSTAT (v1.0): a PYTHON package for computing turbulence statistics in spectral-line data cubes. TURBUSTAT includes implementations of 14 methods for recovering turbulent properties from observational data. Additional features of the software include: distance metrics for comparing two data sets; a segmented linear model for fitting lines with a break point; a two-dimensional elliptical power-law model; multicore fast-Fourier-transform support; a suite for producing simulated observations of fractional Brownian Motion fields, including two-dimensional images and optically thin H I data cubes; and functions for creating realistic world coordinate system information for synthetic observations. This paper summarizes the TURBUSTAT package and provides representative examples using several different methods. TURBUSTAT is an open-source package and we welcome community feedback and contributions.

We announce the discovery of KELT-23Ab, a hot Jupiter transiting the relatively bright (V = 10.3) star BD+66 911 (TYC 4187-996-1), and characterize the system using follow-up photometry and spectroscopy. A global fit to the system yields host-star properties of T-eff = 5900 +/- 49 K, M* = 0.945(-0.054)(+0.060) M-circle dot, R* = 0.995 +/- 0.015 R-circle dot, L* = 1.082(-0.048)(+0.051) L-circle dot, log g* = 4.418(-0.025)(+0.026). (cgs), and [Fe/H] = -0.105 +/- 0.077. KELT-23Ab is a hot Jupiter with a mass of M-p = 0.938(-0.042)(+0.045). M-J, radius of R-p = 1.322 0.025 R-J, and density of rho(p) = 0.504(0.035)(+0.038) g cm(-3). Intense insolation flux from the star has likely caused KELT-23Ab to become inflated. The time of inferior conjunction is T-0 = 2458149.40776 +/- 0.00091 BJD(TDB) and the orbital period is P = 2.255353(-0.000030)(+0.000031) ON days. There is strong evidence that KELT-23A is a member of a long-period binary star system with a less luminous companion, and due to tidal interactions, the planet is likely to spiral into its host within roughly a gigayear. This system has one of the highest positive ecliptic latitudes of all transiting planet hosts known to date, placing it near the Transiting Planet Survey Satellite and James Webb Space Telescope continuous viewing zones. Thus we expect it to be an excellent candidate for long-term monitoring and follow up with these facilities.