We present 3D global MHD simulations of proto-planetary disks calculated with the ZeusMP code. We focus on gas dynamics; the magnetic diffusivity and temperature are fixed during the simulation. A zone with low gas ionization at the midplane is included within ±2 scale heights. We mimic the ‘snow’-line radius with one order of magnitude jump in magnetic diffusivity η. Resulting turbulent Maxwell and Reynolds stresses are present at the midplane despite of low ionization. We find no radial inhomogeneities in turbulent α stress for a mild ionization contrast at the ‘snow’-line. A smooth azimuthal magnetic field is produced in the dead zone which may be a driving force for a weak accretion flow.

We present a new method to solve for the star-formation history (SFH) of a complex stellar population system from the analysis of the color-magnitude diagram (CMD). The SFH is obtained in four steps: i) computing a synthetic CMD, ii) simulating observational effects, iii) parameterization and sampling of the synthetic and observed CMDs, and iv) solving and averaging the solutions. The consistency and stability of the method have been tested using a mock stellar population.

The method has been used to solve the SFH of a set of six isolated Local Group dwarf galaxies observed with HST. The main goal is to probe the effects of cosmological processes, such as reionization in the early star formation, or the ability of SNe feedback to remove gas in small halos, in dwarf galaxies free from environmental effects due to the strong interaction with the host galaxy.

We describe two studies of the interstellar magnetic field in regions of the Small Magellanic Cloud (SMC), including those affected by the interaction with the Large Magellanic Cloud (LMC). We use optical polarization data from aligned grains in the interstellar medium of the SMC in order to map the sky-projected direction of the magnetic field and determine characteristics of the SMC and Pan-Magellanic field structures. The earlier, photoelectric data are reanalyzed and they provide values for the average projected magnetic field intensity (1.7 × 10−6 G) and the random field component intensity (3.5 × 10−6 G). Another on-going program uses imaging data and, when concluded, will allow more local estimates of the field intensity in the SMC NE/Wing regions. Additional goals include cross-correlating our field mapping results with those of point sources and structures found by the Spitzer Space Telescope in the SMC between 3.6 and 8 μm.

Observations of core collapse supernovae and their progenitors generally support expectations of increasing mass loss with increasing initial mass. Mass loss rates are expected to decline at lower metallicity, and there are prospects for directly testing this for the red supergiant progenitors of Type IIP supernovae. However, there are indications that mass loss rates for high mass early type stars may be overestimated and that there are mass loss mechanisms that do not decline at lower metallicity. In this case, there may be supernova emission from strong circumstellar interaction even at low metallicity. Although there is evidence for dust formation in freely expanding ejecta of supernovae, the quantities are relatively small. Another promising site of dust formation is the circumstellar interaction region, but this should occur in only a fraction of supernovae.

We present the physical structure (density and temperature profiles) and the distribution of formaldehyde and methanol in intermediate mass protostar OMC2-FIR4 in the Orion molecular cloud complex.

Transiting planets are generally close enough to their host stars that tides may govern their orbital and thermal evolution. We present calculations of the tidal evolution of recently discovered transiting planets and discuss their implications. The tidal heating that accompanies this orbital evolution can be so great that it controls the planet's physical properties and may explain the large radii observed in several cases, including, for example, TrES-4. Also, since a planet's transit probability depends on its orbit, it evolves due to tides. Current values depend sensitively on the physical properties of the star and planet, as well as on the system's age. As a result, tidal effects may introduce observational biases in transit surveys, which may already be evident in current observations. Transiting planets tend to be younger than non-transiting planets, an indication that tidal evolution may have destroyed many close-in planets. Also the distribution of the masses of transiting planets may constrain the orbital inclinations of non-transiting planets.

Commission 53 on Extrasolar Planets was created at the 2006 Prague General Assembly of the IAU, in recognition of the outburst of astronomical progress in the field of extrasolar planet discovery, characterization, and theoretical work that has occurred since the discovery of the pulsar planets in 1992 and the discovery of the first planet in orbit around a solar-type star in 1995. Commission 53 is the logical successor to the IAU Working Group on Extrasolar Planets WG-ESP, which ended its six years of existence in August 2006. The founding president of Commission 53 is Michael Mayor, in honor of his seminal contributions to this new field of astronomy. The vice-president is Alan Boss, the former chair of the WG-ESP, and the members of the Commission 53 Organizing Committee are the other former members of the WG-ESP.

I discuss how the chemical abundance distributions, kinematics and age distributions of stars in the thin and thick disks of the Galaxy can be used to decipher the merger history of the Milky Way, a typical large galaxy. The observational evidence points to a rather quiescent past merging history, unusual in the context of the ‘consensus’ cold-dark-matter cosmology favoured from observations of structure on scales larger than individual galaxies.

We positionally cross-identified FIRST (the Faint Images of the Radio Sky at Twenty centimeters) catalogue with 2MASS (the Two Micron All Sky Survey) pointed-source database and collected the data from radio band and near infrared band. Then the data were cross-matched with the Véron-Cetty & Véron 2006 catalog and the Tycho-2 catalog, respectively. Therefore the known samples of quasars and stars are obtained. We applied principal component analysis (PCA) on the known sample. The overall sample may be projected in the principal component space. From the space, we can easily locate the area that radio stars occupy, and select out radio star candidates. With the follow-up observation of these candidates, the properties of radio stars may be studied.

We present 2-D numerical simulations of wave propagation in the magnetic network. The network is modelled as consisting of individual magnetic flux sheets located in intergranular lanes. They have a typical horizontal size of about 150 km at the base of the photosphere and expand upward and become uniform. We consider flux sheets of different field strengths. Waves are excited by means of transverse motions at the lower boundary, to simulate the effect of granular buffeting. We look at the magneto-acoustic waves generated within the flux sheet and the acoustic waves generated in the ambient medium due to the excitation. We calculate the wave energy fluxes separating them into contributions from the acoustic and the Poynting part and study the effect of the different field strengths.

We carry out a Monte-Carlo simulation to study the formation of methanol on the grain surfaces. We found that the recombination efficiencies are strongly dependent on the extrinsic properties of the grain, such as the number of sites on the grain surface and the flux of the accreting matter. This uses the concept of effective grain surface (denoted through a factor α) area which changes as the grain is populated.

Early results from the SAGE-SMC (Surveying the Agents of Galaxy Evolution in the tidally-disrupted, low-metallicity Small Magellanic Cloud) Spitzer legacy program are presented. These early results concentrate on the SAGE-SMC MIPS observations of the SMC Tail region. This region is the high H i column density portion of the Magellanic Bridge adjacent to the SMC Wing. We detect infrared dust emission and measure the gas-to-dust ratio in the SMC Tail and find it similar to that of the SMC Body. In addition, we find two embedded cluster regions that are resolved into multiple sources at all MIPS wavelengths.

We have now entered a phase of extrasolar planets characterization: probing their atmospheres for molecules, constraining their horizontal and vertical temperature profiles and estimating the contribution of clouds and hazes. We review here the current situation with ground-based and space-based observations, and present the transmission spectra of HD189733b in the spectral range 0.5-24 microns.

The very peculiar abundance patterns observed in extremely metal-poor (EMP) stars can not be explained by conventional normal supernova nucleosynthesis but can be well-reproduced by nucleosynthesis in hyper-energetic and hyper-aspherical explosions, i.e., Hypernovae (HNe). Previously, such HNe have been observed only as Type Ic supernovae. Here, we examine the properties of recent Type Ib supernovae (SNe Ib). In particular, SN Ib 2008D associated with the luminous X-ray transient 080109 is found to be a more energetic explosion than normal core-collapse supernovae. We estimate that the progenitor's main sequence mass is MMS = 20 − 25M⊙ with an explosion of kinetic energy of EK ~ 6.0 × 1051 erg. These properties are intermediate between those of normal SNe and hypernovae associated with gamma-ray bursts. Therefore, such energetic SNe Ib could also make an important contribution to the chemical enrichment in the early Universe.

We present the properties of a large sample (12,282) of nearly face-on low surface brightness disk galaxies selected from the main galaxy sample of SDSS-DR4. Those properties includes B-band central surface brightness μ0(B), scale lengths h, distances D, integrated magnitudes, colors and some resulted relations. This sample has μ0(B) from 22 to 24.5 mag arcsec−2 with a median value of 22.44 mag arcsec−2. They are quite bright with MB taking values from −18 to −23 mag with a median value of −20.08 mag. The disk scale lengths h are from 2 kpc to 19 kpc. There exist clear correlations between log h and MB, log h and log D. Both the optical-optical and optical-NIR color-color relations show most of them have a mix of young and old stellar populations.

The activity of the Minor Planet Center continued generally to increase during the two triennia covered by this report, principally because of the continuing success of the surveys for near-earth objects. Chief among these has been the Lincoln (Laboratory) Near-Earth Asteroid Research Project, or LINEAR, which is credited with the discovery of slightly more than half of all the minor planets that have been numbered, although since 2005 the Catalina Sky Survey and Mount Lemmon Survey in Arizona and the Siding Spring Survey in New South Wales (all three of which, together with the long-lasting Spacewatch Survey, are operated from the University of Arizona) have come to dominate the field. The total number of observations of minor planets in the MPC's files more than doubled from 14.1 million in mid-2002 to 30.9 million in mid-2005, with almost another doubling, to 55.4 million, in mid-2008.

Recent data have revealed a clear distinction between the abundance patterns of the Milky Way (MW) thick and thin disks, suggesting a different origin for each of these components. In this work we first review the main ideas on the formation of the thin disk. From chemical evolution arguments we show that the thin disk should have formed on a long timescale. We also show clear signs that the local stellar samples are contaminated by stars coming from inner radii. We then check what would have to be changed in such a model in order to explain the observables in the thick disk. We find that a model in which the thick disk forms on a much shorter timescale than thin disk and with a star formation efficiency of around a factor of 10 larger than that in the thin disk can account for the observed abundance ratio shifts of several elements between thick and thin disk stars. Moreover, the lack of scatter in the abundance ratio patterns of both the thick and thin disks suggest both components to have been formed in situ by gas accretion and not by mergers of smaller stellar systems. Especially for the thick disk, this last constraint becomes a strong one if its metallicity distribution extends to, at least, solar. Finally, we briefly discuss the interplay between present deuterium abundance and present infall rates in connection with the thin disk evolution.

In ultra dense and hot region realized in stellar core-collapse, neutrino takes major role in energy and momentum transports. We investigate the growth of magnetorotational instability (MRI) in neutrino viscous matter by using linear theory. It is found from the local linear analysis that the neutrino viscosity can suppress the MRI in the regime of weak magnetic field (B ≪ 1014G). This suggest that MHD turbulence sustained by the MRI might not be driven efficiently in the neutrino viscous media. Applying this result to collapsar disk, which is known as the central engine of gamma-ray burst (GRB), we find that the MRI can be suppressed only in its inner region. Based on this finding, a new evolutionary scenario of collapsar disk, “Episodic Disk Accretion Model” are proposed.

The spreads in chemical abundances inferred by recent precision observations suggest that some or possibly all globular clusters can no longer be considered as simple stellar populations. The most striking case is ω Cen in the sense that its bluest main-sequence, despite its high metallicity, demands an extreme helium abundance of Y ≈ 0.4. I focus on this issue of “the extreme helium population problem” in this review.

Coronal Mass Ejections (CMEs) have been addressed by a particularly active research community in recent years. With the advent of the International Heliophysical Year and the new STEREO and Hinode missions, in addition to the on-going SOHO mission, CME research has taken centre stage in a renewed international effort. This review aims to touch on some key observational areas, and their interpretation. First, we consider coronal dimming, which has become synonymous with CME onsets, and stress that recent advances have heralded a move from a perceived association between the two phenomena to a firm, well-defined physical link. What this means for our understanding of CME modeling is discussed. Second, with the new STEREO observations, and noting the on-going SMEI observations, it is important to review the opening field of CME studies in the heliosphere. Finally, we discuss some specific points with regard to EIT-waves and the flare-CME relationship. In the opinion of the author, these issues cover key hot topics which need consideration for significant progress in the field.