We have measured the distance to the high-mass star-forming region G59.7+0.1 (IRAS 19410+2336) and W3OH. Their distances, 2.20 ± 0.11 kpc and 1.95 ± 0.04 kpc, respectively, were determined by triangulation using Very Long Baseline Array (VLBA) observations of 12.2 GHz methanol masers phase-referenced to compact extragalactic radio sources. In addition to the distances, we have also obtained their proper motions.

In this contribution we review the main observational properties of Blue Stragglers Stars (BSS) in galactic GCs. A flower of results on the BSS frequency, radial distribution, and chemical composition are presented and discussed.

The Arecibo L-band Feed Array Zone of Avoidance Survey (ALFA ZOA) will map 1350-1800 deg2 at low Galactic latitude, providing HI spectra for galaxies in regions of the sky where our knowledge of local large scale structure remains incomplete, owing to obscuration from dust and high stellar confusion near the Galactic plane. Because of these effects, a substantial fraction of the galaxies detected in the survey will have no optical or infrared counterparts. However, near infrared follow up observations of ALFA ZOA sources found in regions of lowest obscuration could reveal whether some of these sources could be objects in which little or no star formation has taken place (“dark galaxies”). We present here the results of ALFA ZOA precursor observations on two patches of sky totaling 140 deg2 (near l = 40°, and l = 192°). We have measured HI parameters for detections from these observations, and cross-correlated with the NASA/IPAC Extragalactic Database (NED). A significant fraction of the objects have never been detected at any wavelength. For those galaxies that have been previously detected, a significant fraction have no previously known redshift, and no previous HI detection.

For a sample of 52 double-peaked broad-lines AGNs from the Sloan Digital Sky Survey (SDSS), we do the spectral decomposition to obtain the host spectrum and the nuclei spectrum from their SDSS spectra, as well as the bulge luminosity (Lbulge), stellar velocity dispersion (σ*). A strong correlation is found between the σ* and the gaseous velocity dispersion in narrow line regions. With the Mbh − σ* relation, we estimate the black hole masses, range from 1.0 × 107 to 6 × 108 M⊙, and the Eddington ratio from about 0.01 to about 1. It is consistent with the result from Mbh − Lbulge relation. However, it is not consistent with the mass from the Hβ FWHM. It seems that the empirical size-luminosity relation for broad line regions dose not hold for double-peaked AGNs, otherwise the calibration factor is as small as 0.185, suggesting the non-virial dynamics of broad line regions.

Rapidly-evolving red supergiants (RSG) lose half or more of their mass before ending their lives as supernovae. Masers allow us to study the mass loss from 4 nearby RSG in AU-scale detail using MERLIN and EVN/global VLBI. The water maser clouds are over-dense and over-magnetised with respect to the surrounding wind. In most cases, the brighter an individual maser component is the smaller its apparent (beamed) FWHM appears, as predicted for approximately spherical clouds. Individual water maser features have a typical half-life of 5-10 yr, but comparison with single dish monitoring suggests that the water vapour clouds themselves survive many decades (the water maser shell crossing time), within which the local masers wink on and off. OH mainline masers are found in the tenuous surrounding gas, overlapping the water maser shell, surrounded by OH 1612-MHz masers at a greater distance from the star.

Recently a new approach was presented where astronomical objects as galaxies and clusters are idealized as self-gravitating systems living in a universe endowed with more than 3+1 dimensions. A such paradigm, named GEDi (Gravitation with Extra Dimensions), may solve exactly the missing mass problem for rotation curves of galaxies or gravitational lensing of clusters with no dark matter particles. Here we present an introductory discussion about the construction of a real galaxy using a Miyamoto-Nagai solution for isotropical coordinates to mimic spiral galaxies with bulges.

The Working Group Historical Instruments (WG-HI) was founded by the members of Commission 41 at the 2000 Manchester IAU XXIV General Assembly, with the main objectives to assemble a bibliography of existing publications relating to such instruments, and to encourage colleagues to carry out research and publish their results. Membership of the WG-HI has increased from three to nine people since its foundation. This clearly demonstrates the IAU members increasing interest in safeguarding old astronomical instruments and buildings as witness to their own country's cultural heritage and scientific progress.

Globular clusters produce orders of magnitude more millisecond pulsars per unit mass than the Galactic disk. Since the first cluster pulsar was uncovered 20 years ago, at least 138 have been identified – most of which are binary millisecond pulsars. Because their origins involve stellar encounters, many of the systems are exotic objects that would never be observed in the Galactic disk. Examples include pulsar-main sequence binaries, extremely rapid rotators (including the current record holder), and millisecond pulsars in highly eccentric orbits. These systems are allowing new probes of the interstellar medium, the equation of state of material at supra-nuclear density, the masses of neutron stars, and globular cluster dynamics.

The ESA space astrometry mission Gaia will measure the positions, parallaxes and proper motions of the 1 billion brightest stars on the sky. Expected accuracies are in the 7–25 μas range down to 15 mag and sub-mas accuracies at the faint limit (20 mag). The astrometric data are complemented by low-resolution spectrophotometric data in the 330–1000 nm wavelength range and, for the brighter stars, radial velocity measurements. The scientific case covers an extremely wide range of topics in galactic and stellar astrophysics, solar system and exoplanet science, as well as the establishment of a very accurate, dense and faint optical reference frame. With a planned launch around 2012 and an (extended) operational lifetime of 6 years, final results are expected around 2021. We give a brief overview of the science goals of Gaia, the overall project organisation, expected performance, and some key technical features and challenges.

We use a multi-dimensional hydrodynamics code to study the gravitational interaction between an embedded planet and a protoplanetary disk with emphasis on the generation of vortensity (Potential Vorticity or PV) through a Baroclinic Instability. We show that the generation of PV is very common and effective in non-barotropic disks through the Baroclinic Instability, especially within the coorbital region. Our results also complement previous work that non-axisymmetric Rossby-Wave Instabilities (RWIs) are likely to develop at local minima of PV distribution that are generated by the interaction between a planet and an inviscid barotropic disk. The development of RWIs results in non-axisymmetric density blobs, which exert stronger torques onto the planet when they move to the vicinity of the planet. Hence, large amplitude oscillations are introduced to the time behavior of the total torque acted on the planet by the disk. In current simulations, RWIs do not change the overall picture of inward orbital migration but cause a non-monotonic behavior to the migration speed. As a side effect, RWIs also introduce interesting structures into the disk. These structures may help the formation of Earth-like planets in the Habitable Zone or Hot Earths interior to a close-in giant planet.

The location of two nearby galaxy groups within ~20 Mpc in the Leo region allows for a detailed study of low-mass galaxies. A catalog of HI line detections in Leo (9h36m < α < 11h36m, +8° < δ < +16°) has been made from the blind HI survey ALFALFA. More sensitive single-pixel Arecibo observations targeted Leo dwarf candidates noted optically by Karachentsev et al. 2004 (K04) to determine group members and allow for a comparison of HI and optically-selected samples. This presentation highlights the differences between the two samples and the significant contribution blind HI surveys can make to the missing satellites problem.

We study the pairing of massive black holes embedded in a massive circum–nuclear, rotationally supported disc, until they form a close binary. Using high resolution SPH simulations, we follow the black hole dynamics, and in particular the eccentricity evolution, as a function of the composition in stars and gas of the disc. Binary–disc interaction always leads to orbital decay and, in case of co–rotating black holes, to orbit circularization. We present also a higher resolution simulation performed using the particle–splitting technique showing that the binary orbital decay is efficient down to a separation of ~ 0.1 pc, comparable to our new resolution limit. We detail the gaseous mass profile bound to each black hole. Double nuclear activity is expected to occur on an estimated timescale of ≲ 10 Myrs.

Gaia is an ambitious space astrometry mission of ESA with a main objective to map the sky in astrometry and photometry down to a magnitude 20 by the end of the next decade. While the mission is built and operated by ESA and an industrial consortium, the data processing is entrusted to a consortium formed by the scientific community, which was formed in 2006 and formally selected by ESA one year later. The satellite will downlink around 100 TB of raw telemetry data over a mission duration of 5 years from which a very complex iterative processing will lead to the final science output: astrometry with a final accuracy of a few tens of microarcseconds, epoch photometry in wide and narrow bands, radial velocity and spectra for the stars brighter than 17 mag. We discuss the general principles and main difficulties of this very large data processing and present the organization of the European Consortium responsible for its design and implementation.

The International Astronomical Union (IAU) was founded in 1922 to “promote and safeguard astronomy . . . and to develop it through international co-operation”. The IAU is funded through its National Members. Almost all of the funds supplied from the dues are used for the development of astronomy.

We investigate the migration of two giant planets embedded in a proto-stellar disk. The inner planet(initially located at R10=1) is of 1 Jupiter mass and the outer one(R20=1.5) is of 1 Saturn mass. We find that due to the existence of the inner massive planet, the outer planet can not open a clear gap. Instead of an inward migration and being captured by the mean motion resonance of the inner planet, the outer planet undergoes an outward runaway migration. We conclude that this runaway migration is caused by the co-rotation torque in the co-orbital region of the outer planet and sustained by the wave(flow) driven by the inner massive planet.

We report on the (serendipitous) detection and analysis of an extremely massive HI cloud without an obvious stellar counterpart nearby the relatively isolated giant spiral galaxy NGC 1030 and present first results of this dark galaxy candidate.

Low-mass X-ray binaries, recycled pulsars, cataclysmic variables and magnetically active binaries are observed as X-ray sources in globular clusters. We discuss the classification of these systems, and find that some presumed active binaries are brighter than expected. We discuss a new statistical method to determine from observations how the formation of X-ray sources depends on the number of stellar encounters and/or on the cluster mass. We show that cluster mass is not a proxy for the encounter number, and that optical identifications are essential in proving the presence of primordial binaries among the low-luminosity X-ray sources.

We present the results of SiO line observations of a sample of known SiO maser sources covering a wide dust-temperature range. The aim of the present research is to investigate the causes of the correlation between infrared colors and SiO maser intensity ratios among different transition lines. We observed in total 75 SiO maser sources with the Nobeyama 45m telescope quasi-simultaneously in the SiO J = 1-0 v = 0, 1, 2, 3, 4 and J = 2-1 v = 1, 2 lines. We also observed the sample in the 29SiO J = 1-0 v = 0 and J = 2-1 v = 0, and 30SiO J = 1-0 v = 0 lines, and the H2O 61,6-52,3 line. As reported in previous papers, we confirmed that the intensity ratios of the SiO J = 1-0 v = 2 to v = 1 lines clearly correlate with infrared colors. In addition, we found possible correlation between infrared colors and the intensity ratios of the SiO J = 1-0 v = 3 to v = 1&2 lines.

The Program Group for the World-wide Development of Astronomy (PG-WWDA) is one of nine Commission 46 program groups engaged with various aspects of astronomical education or development of astronomy education and research in the developing world. In the case of PG-WWDA, its goals are to promote astronomy education and research in the developing world through a variety of activities, including visiting astronomers in developing countries and interacting with them by way of giving encouragement and support.

SIM PlanetQuest is a very high accuracy space astrometric instrument based on a long baseline stellar interferometer. For global astrometry SIM was designed to be accurate to ≈ 4μas (microarcsec) after a 5 year mission. For narrow angle astrometry (≈ 1000 s integration over a 1° radius field) SIM is designed for 1μas precision. The technology program was completed in 2005 and based on laboratory results, the current best estimate of SIM's performance would be 0.6 μas for narrow angle precision and 2.4 μas for global accuracy. This paper describes a variety of science programs that the SIM science team have proposed to conduct from a search for one Earth mass planets in the habitable zone of (≈130) nearby stars to the study of dark matter in the galactic disk, the galactic halo and the local group.