We use photometric and spectroscopic observations of the eclipsing binaries V65, V66, and V69 in the field of the globular cluster M4 to derive masses, radii, and luminosities of their components. The orbital periods of these systems are 2.29, 8.11, and 48.19 days, respectively. The measured masses of the primary and secondary components (M-p and M-s) are 0.8035 +/- 0.0086 and 0.6050 +/- 0.0044 M-circle dot for V65, 0.7842 +/- 0.0045 and 0.7443 +/- 0.0042 M-circle dot for V66, and 0.7665 +/- 0.0053 and 0.7278 +/- 0/0048 M-circle dot for V69. The measured radii (R-p and R-s) are 1.147 +/- 0.010 and 0.6110 +/- 0.0092 R-circle dot for V66, 0.9347 +/- 0.0048 and 0.8298 +/- 0.0053 R-circle dot for V66, and 0.8655 +/- 0.0097 and 0.8074 +/- 0.0080 R-circle dot for V69. The orbits of V65 and V66 are circular, whereas that of V69 has an eccentricity of 0.38. Based on systemic velocities and relative proper motions, we show that all three systems are members of the cluster. We find that the distance to M4 is 1.82 +/- 0.04 kpc-in good agreement with recent estimates based on entirely different methods. We compare the absolute parameters of V66 and V69 with two sets of theoretical isochrones in mass-radius and mass-luminosity diagrams, and for assumed [Fe/H] = -1.20, [alpha/Fe] = 0.4, and Y= 0.25 we find the most probable age of M4 to be between 11.2 and 11.3 Gyr. Color-magnitude diagram (CMD) fitting with the same parameters yields an age close to, or slightly in excess of, 12 Gyr. However, considering the sources of uncertainty involved in CMD fitting, these two methods of age determination are not discrepant. Age and distance determinations can be further improved when infrared eclipse photometry is obtained.

We report two low-mass companions orbiting the nearby K7 dwarf GJ 221 that have emerged from reanalyzing 4.4 yr of publicly available HARPS spectra complemented with 2 years of high-precision Doppler measurements with Magellan/PFS. The HARPS measurements alone contain the clear signal of a low-mass companion with a period of 125 days and a minimum mass of 53.2 M-circle plus (GJ 221b), falling in a mass range where very few planet candidates have been found (sub-Saturn desert). The addition of 17 PFS observations allows the confident detection of a second low-mass companion (6.5M(circle plus)) in a hot orbit (3.87 day period, GJ 221c). Spectroscopic and photometric calibrations suggest that GJ 221 is slightly depleted ([Fe/H]similar to-0.1) compared to the Sun, so the presence of two low-mass companions in the system confirms the trend that slightly reduced stellar metallicity does not prevent the formation of planets in the super-Earth to sub-Saturn mass regime.

We derive relative proper motions of stars in the fields of globular clusters M4, M12, M22, NGC 3201, NGC 6362 and NGC 6752 based on a uniform data set collected between 1997 and 2008. We assign a membership class for each star with a measured proper motion and show that these membership classes can be successfully used to eliminate field stars from color-magnitude diagrams of the clusters. They also allow for the efficient selection of rare objects such as blue/yellow/red stragglers and stars from the asymptotic giant branch. Tables with proper motions and photometry of over 87 000 stars are made publicly available via the Internet.

We analyze light and velocity curves of the eclipsing blue straggler V60 in the field of the globular cluster M55. We derive M-p = 1.259 +/- 0.025 M-circle dot, R-p = 1.102 +/- 0.021 R-circle dot, M-p(bol) = 3.03 +/- 0.09 mag for the primary and M-s = 0.327 +/- 0.017 M-circle dot, R-s = 1.480 +/- 0.011 R-circle dot, M-s(bol) = 4.18 +/- 0.12 mag for the secondary. We measure an apparent distance modulus (m - M)(V) = 14.04 +/- 0.09 mag. Based on the systemic velocity, distance, and proper motion of V60 we conclude that the system is a member of the cluster and argue that its present state is a result of rapid but conservative mass exchange which the binary is still undergoing. We report a peculiar blue excess on the ascending branch of the primary eclipse of V60 and discuss its possible origin.

We present six years of new radial velocity data from the Anglo-Australian and Magellan Telescopes on the HD 73526 2:1 resonant planetary system. We investigate both Keplerian and dynamical ( interacting) fits to these data, yielding four possible configurations for the system. The new data now show that both resonance angles are librating, with amplitudes of 40 degrees and 60 degrees, respectively. We then perform long-term dynamical stability tests to differentiate these solutions, which only differ significantly in the masses of the planets. We show that while there is no clearly preferred system inclination, the dynamical fit with i = 90 degrees provides the best combination of goodness-of-fit and long-term dynamical stability.

High-dispersion observations of the Na I D lambda lambda 5890, 5896 and K I lambda lambda 7665, 7699 interstellar lines, and the diffuse interstellar band at 5780 angstrom in the spectra of 32 Type Ia supernovae are used as an independent means of probing dust extinction. We show that the dust extinction of the objects where the diffuse interstellar band at 5780 angstrom is detected is consistent with the visual extinction derived from the supernova colors. This strongly suggests that the dust producing the extinction is predominantly located in the interstellar medium of the host galaxies and not in circumstellar material associated with the progenitor system. One quarter of the supernovae display anomalously large Na I column densities in comparison to the amount of dust extinction derived from their colors. Remarkably, all of the cases of unusually strong Na I D absorption correspond to "Blueshifted" profiles in the classification scheme of Sternberg et al. This coincidence suggests that outflowing circumstellar gas is responsible for at least some of the cases of anomalously large Na I column densities. Two supernovae with unusually strong Na I D absorption showed essentially normal K I column densities for the dust extinction implied by their colors, but this does not appear to be a universal characteristic. Overall, we find the most accurate predictor of individual supernova extinction to be the equivalent width of the diffuse interstellar band at 5780 angstrom, and provide an empirical relation for its use. Finally, we identify ways of producing significant enhancements of the Na abundance of circumstellar material in both the single-degenerate and double-degenerate scenarios for the progenitor system.

We report the discovery of HATS-5b, a transiting hot Saturn orbiting a G-type star, by the HATSouth survey. HATS-5b has a mass of Mp approximate to 0.24 M-J, radius of R-p approximate to 0.91 R-J, and transits its host star with a period of P approximate to 4.7634 days. The radius of HATS-5b is consistent with both theoretical and empirical models. The host star has a V-band magnitude of 12.6, mass of 0.94 M-circle dot, and radius of 0.87 R-circle dot. The relatively high scale height of HATS-5b and the bright, photometrically quiet host starmake this planet a favorable target for future transmission spectroscopy follow-up observations. We reexamine the correlations in radius, equilibrium temperature, and metallicity of the close-in gas giants and find hot Jupiter-mass planets to exhibit the strongest dependence between radius and equilibrium temperature. We find no significant dependence in radius and metallicity for the close-in gas giant population.

Photometric observations of GQ Mus performed between 1992 and 2011 are reported. We find that the total amplitude of the orbital modulation of its brightness decreased from similar to 0.9 mag in 1992 to similar to 0.2 mag in 2010, becoming comparable to the amplitude of chaotic flickering on a time scale of several minutes. Optical spectra obtained in 2001 and 2012 indicate continuing activity of GQ Mus. The spectra show broad emission lines of He II and H I typical for magnetic cataclysmic variables. The nova was found to be an UV-bright object in 2001 and 2012. We also show that the orbital period of GQ Mus has been constant between 1989 and 2010-2011.

We report the discovery by the HATSouth survey of HATS-4b, an extrasolar planet transiting a V = 13.46 mag G star. HATS-4b has a period of P approximate to 2.5167 days, mass of M-p approximate to 1.32 M-Jup, radius of R-p approximate to 1.02 R-Jup, and density of rho(p) = 1.55 +/- 0.16 g cm(-3) approximate to 1.24 rho(Jup). The host star has a mass of 1.00 M-circle dot, a radius of 0.92 R-circle dot, and a very high metallicity [Fe/H]= 0.43 +/- 0.08. HATS-4b is among the densest known planets with masses between 1 and 2 M-J and is thus likely to have a significant content of heavy elements of the order of 75 M-circle plus. In this paper we present the data reduction, radial velocity measurements, and stellar classification techniques adopted by the HATSouth survey for the CORALIE spectrograph. We also detail a technique for simultaneously estimating nu sin i and macroturbulence using high resolution spectra.

We report the detection of GJ 832c, a super-Earth orbiting near the inner edge of the habitable zone of GJ 832, an M dwarf previously known to host a Jupiter analog in a nearly circular 9.4 yr orbit. The combination of precise radial-velocity measurements from three telescopes reveals the presence of a planet with a period of 35.68 +/- 0.03 days and minimum mass (m sin i) of 5.4 +/- 1.0 Earth masses. GJ 832c moves on a low-eccentricity orbit (e = 0.18 +/- 0.13) toward the inner edge of the habitable zone. However, given the large mass of the planet, it seems likely that it would possess a massive atmosphere, which may well render the planet inhospitable. Indeed, it is perhaps more likely that GJ 832c is a "super-Venus," featuring significant greenhouse forcing. With an outer giant planet and an interior, potentially rocky planet, the GJ 832 planetary system can be thought of as a miniature version of our own solar system.