Since the IAU General Assembly in Sydney in July 2003, the WGPSN has conducted its business through numerous e-mail exchanges between the members. A nomenclature workshop was held at Hardingasete, western Norway on September 1–3, 2005. That meeting was attended by eight members from the WG and two from the Task Groups (TG) for the small bodies and for the outer solar system. Input to the meeting had also been received by e-mail from other members.

Observations suggest systematic differences between chemical abundances of stars in satellite galaxies and those in the Milky Way halo. Specifically, for the same [Fe/H] values, stars in surviving satellite galaxies display significantly lower [α/Fe] ratios than stars in the stellar halo.

Here we investigate whether the observed differences can be explained in the framework of hierarchical structure formation. We model the chemical enrichment of a typical Milky Way galaxy in a ΛCDM Universe using, in combination, i) a semi-analytical code and numerical simulations that model the accretion and disruption of halo substructure and ii) a chemical evolution model that takes into account each satellite's star formation, metal enrichment and stellar feedback. Our results suggest that the observed chemical abundance patterns are a natural outcome in the process of hierarchical assembly of the Galaxy. We find that the stellar halo is built up from satellite galaxies accreted early on (more than 8–9 Gyr ago) and enriched in α-elements produced in Type II supernovae (average [α/Fe] values between 0.2–0.5). In contrast, satellites which survive today were typically accreted late (within the last 4–5 Gyr) and had at the time of accretion nearly solar [α/Fe] values as a result of the longer contribution of Type Ia supernovae.

We examine the origin of water in the terrestrial planets. We list various geochemical measurements that may be used to discriminate between different endogenous and exogenous sources of water. Late stage delivery of significant quantities of water from asteroidal and cometary sources appears to be ruled out by isotopic and molecular ratio considerations, unless either comets and asteroids currently sampled spectroscopically and by meteorites are unlike those falling to Earth 4.5 Ga ago or our measurements are not representative of those bodies. The dust in the accretion disk from which terrestrial planets formed was bathed in a gas of H, He and O. The dominant gas phase species were H2O, He, H2O, and CO. Thus grains in the accretion disk must have been exposed to and adsorbed H2 and water. We examine the efficacy of nebular gas adsorption as a mechanism by which the terrestrial planets accreted “wet”. A simple model suggests that grains accreted to Earth could have adsorbed 1 - 3 Earth oceans of water. The fraction of this water retained during accretion is unknown, but these results suggest that at least some of the water in the terrestrial planets may have originated by adsorption.

The Swift Gamma-ray Burst Explorer mission, launched on 2004 November 20, is a multiwavelength observatory for gamma-ray burst (GRB) astronomy. The satellite carries three instruments: a new-generation wide-field gamma-ray (15–150 keV) detector that detects bursts, calculates 1–4 arcmin positions, and triggers autonomous spacecraft slews; a narrow-field X-ray telescope that gives 5 arcsec positions and performs spectroscopy in the 0.2 to 10 keV band; and a narrow-field UV/optical telescope that operates in the 170–600 nm band and provides 0.3 arcsec positions and optical finding charts. In the first 8 months of the mission (until the end of July 2005), Swift detected 54 GRBs performing detailed X-ray and UV/optical afterglow observations spanning timescales from 1 minute to several days after the burst. Swift has already collected a rich trove of early X-ray afterglow data and some interesting features are emerging. In particular early afterglow signatures reveal valuable and unprecedented information about GRBs, including the prompt emission – afterglow transition, GRB emission site, central engine activity, forward-reverse shock physics, and the GRB immediate environment.

Cosmological variations in the fine structure constant, $\alpha$, can be probed through precise velocity measurements of metallic absorption lines from intervening gas clouds seen in spectra of distant quasars. Data from the Keck/HIRES instrument support a variation in $\alpha$ of 6 parts per million. Such a variation would have profound implications, possibly providing a window into the extra spatial dimensions required by unified theories such as string/M-theory. However, recent results from VLT/UVES suggest no variation in $\alpha$. The COsmic Dynamics EXperiment (CODEX) spectrograph currently being designed for the ESO OWL telescope (Pasquini et al. 2005) with a resolution high enough to properly resolve even the narrowest of metallic absorption lines, $R \gt 150000$, will achieve a 2-to-3 order-of-magnitude precision increase in $\Delta\alpha/\alpha$. This will rival the precision available from the Oklo natural fission reactor and upcoming satellite-borne atomic clock experiments. Given the vital constraints on fundamental physics possible, the ELT community must consider such a high-resolution optical spectrograph like CODEX.

Here we examine the visible spectra of giant planets in anticipation of the science return of missions like the Terrestrial Planet Finder-Coronagraph and proposed Discovery class space coronagraph missions EPIC and ECLIPSE. Our understanding of extrasolar giant planets is already greatly improving because of our studies of old brown dwarfs (which have effective temperatures similar to young giant planets), transiting hot Jupiters, and the planet Jupiter itself. The first data collected on Jupiter-like extrasolar giant planets will likely consist of magnitudes in a few filters or very low resolution spectra. We investigate diagnostics for determining planetary effective temperature, atmospheric chemical abundances, cloud cover, and mass using such limited data. In general, giant planet science is improved significantly if missions in the visible domain extend to wavelengths as long as possible, within engineering constraints.

We present Very Long Baseline Array (VLBA) proper motion observations of water masers toward two young stellar objects (YSOs) of the W75N(B) high-mass star forming region. These observations (Torrelles et al. 2003) show two objects having a similar spectral type (early-B stars), separated in the sky by 0$0^''$7 (corresponding to 1400 AU at the source distance), sharing the same molecular gas environment, but presenting a strikingly different outflow ejection geometry. One of these YSOs, W75N(B)-VLA 1, has a jet-like outflow at 2000 AU scale, with the water masers moving at velocities of ${\simeq}$20 km s$^{-1}$ along the major axis of the thermal radio continuum jet, while the other YSO has a water maser shell outflow of 160 AU radius expanding at ${\simeq}$30 km s$^{-1}$ in multiple directions with respect to the central compact radio continuum source W75N(B)-VLA 2. Given the small dynamical time obtained for the water maser shell (${\simeq}$13 yr), we propose that in the very early stages of the star-formation process there may exist short lived, possibly repetitive, events associated with very poorly collimated outflows. All these results suggest that outflow collimation is not only a consequence of ambient conditions, but something intrinsic to the evolution of the individual stars, opening the important question of how and when these non-collimated wind ejection events occur in the evolution of YSOs. Although we argue in this paper that W75N(B)-VLA 2 could be in an earlier stage of evolution than W75N(B)-VLA 1, we think that observations at (sub)millimeter wavelengths with angular resolutions of ${\simeq}0^''1$ can provide the key for determining the relative stage of evolution of these two remarkable YSOs.

The rare light elements — Li, Be, and B — have a unique and highly coupled history in the Universe. A coordinated analysis of their abundances in very low metallicity stars can help us understand the inner workings of stars and can constrain models of Galactic chemical evolution. We measure the Be abundances of nine stars and the Li isotopic ratio of ten stars. We find three stars with interesting Be abundances and three stars with detectable $^6$Li.

Rich molecular complexity has been shown to exist in star forming regions primarily through millimeter to submillimeter single-dish spectral line surveys or searches over the years. With a few case studies, we demonstrate that interferometric observations are a powerful tool for advancing our knowledge of the chemical processes related to the formation of complex organic molecules in these regions. In particular, interferometers are sensitive to compact structures, such as those of the so called “hot molecular core” sources where complex organics are almost exclusively found. The high angular resolutions achieved by interferometers allow us to better spatially discriminate chemical differentiation and, possibly, evolutionary effects.

We present a new semi–analytic treatment of the evolution of galactic winds within high resolution, large scale cosmological N–body simulations of a $\Lambda$CDM Universe. We focus our analysis on the impact of winds on the diffuse intergalactic medium at $z=3$ and we make predictions for the volume filling factor of winds as a function of our model parameters. We then verify this prediction by extracting a set of synthetic spectra along random lines of sight through our simulated box and by calculating the probability distribution function (PDF) of the spectral flux. We find that galactic winds do not significantly modify the PDF. We finally argue that the increased flux transmissivity found by Adelberger et al. (2003) around a small sample of Lyman break galaxies may be explained by the presence of hot ionised bubbles due to pressure–driven winds outflowing from the galaxies. However, this effect cannot be explained by cooled, momentum–driven winds. We conclude that the result of Adelberger et al. (2003) may be the outcome of a selection effect.

Understanding the sources responsible for reionizing the Universe is a key goal of observational cosmology. A discrepancy has existed between the meta-galactic hydrogen ionisation rate, $\Gamma_{\rm HI}$, predicted by early hydrodynamical simulations of the Lyman-$\alpha$ forest if scaled to appropriate assumptions for the IGM temperature, when compared to values predicted from the proximity effect. We present new estimates for $\Gamma_{\rm HI}$ in the redshift range $2<z<4$ based on hydrodynamical simulations of the Lyman-$\alpha$ forest opacity. Within the current concordance cosmology, and assuming updated QSO emissivity rates, a substantial contribution to the UV background from young star-forming galaxies appears to be required over the entire redshift range. Our results are consistent with lower-end estimates from the proximity effect. It is also found that the errors on the ionisation rate are dominated by uncertainties in the thermal state of the intergalactic medium and the r.m.s fluctuation amplitude at the Jeans scale.

Interstellar aldehydes have been called the “sugars of space” ever since the discoveries of formaldehyde (H2CO) in 1969 and acetaldehyde (CH3CHO) in 1973. At present, more than 135 interstellar molecular species have been identified. Excluding diatomic species, 30% of all interstellar molecules have isomeric counterparts. The newest instrument in the interstellar molecule search arsenal is the Green Bank Telescope (GBT), which is credited with the discovery of the large aldehydes propenal (CH2CHCHO) and propanal (CH3CH<2CHO). In addition, the GBT has been used to observe interstellar glycolaldehyde (CH2OHCHO), the simplest possible aldehyde sugar, and interstellar ethylene glycol (HOCH2CH2OH), the sugar alcohol of glycolaldehyde. These new GBT observations that suggest a universal prebiotic chemistry are presented and discussed. While there is no consensus regarding how large complex interstellar molecules are formed, it may be that the first step in the polymerization of interstellar formaldehyde (H2CO) with its isomer trans hydroxy methylene (t-HCOH) is responsible for the formation of interstellar glycolaldehyde. We discuss this polymerization mechanism that can result in the generation of more complex sugars. We assess the likelihood of interstellar trans hydroxy methylene and suggest a search strategy for it using the GBT.

We have computed updated models of population II stars on the Spite plateau. We focus here on the light elements abundance predictions when the new tachocline mixing process is accounted for.

We present here the results of new XMM-Newton observations of the PSR B1259–63 system during the beginning of 2004, as the pulsar approaches the disc of the Be star. We combine these results with earlier X-ray data from BeppoSAX, XMM-Newton, and ASCA. The X-ray light curve looks similar to the radio light curve with a rapid increase in the flux around the time of the disc crossing. This supports a model in which the X-ray emission from the system is due to inverse Compton scattering of the pulsar wind relativistic particles with moderate Lorentz factor $\gamma \sim 10$–100 on the Be star soft photons.

Dwarf galaxies tend to have a large spread in metal abundances and overall lower metallicites than large Spiral or Elliptical ones. Here we propose that if all stars are formed from an invariant canonical IMF within each star cluster which are distributed according to an embedded cluster mass function (ECMF), then the integrated stellar IMF over the whole galaxy (the integrated galaxial IMF, IGIMF) must be steeper than the canonical IMFs within the clusters, and additionally they must depended on the stellar mass of the galaxy. In particular, dwarf galaxies and low-surface brightness galaxies show steeper galaxial IMFs which vary strongly with the star-formation rate. The resulting number of Supernovae II per low-mass star, and the chemical enrichment history of these galaxies therefore vary substantially depending on the galaxy assembly history.

The phase or orbital light curves of extrasolar terrestrial planets in reflected or emitted light will contain information about their atmospheres and surfaces complementary to data obtained by other techniques such as spectrosopy. We show calculated light curves at optical and thermal infrared wavelengths for a variety of Earth-like and Earth-unlike planets. We also show that large satellites of Earth-sized planets are detectable, but may cause aliasing effects if the lightcurve is insufficiently sampled.

The 2003 report of the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements has appeared in Celestial Mechanics and Dynamical Astronomy(2005)volume 91, part 3–4, pages 203–215. The Working Group continues to maintain and update the information for cartographic coordinates and rotational elements for the Sun, Moon, planets, satellites, asteroids, and comets. A report is published treannually. A web site is maintained at http://extranet.astrogeology.wr.usgs.gov/Projects/WGCCRE with the up-to-date information. It is anticipated that the next report will include updates for Saturn (rotation rate) and all of the Saturnian moons, additions for the newly visited comets and asteroids, and a clarification of the Moon's coordinate systems (the mean Earth/polar axis system needs to be defined more precisely).

Wide-field spectroscopy, in its various forms, has much to contribute to ELT science, so care is needed in trade-offs between telescope size and field of view. Integral field spectroscopy over large areas at high spatial resolution, and especially multiple integral fields, will be essential tools. For wide-field surveys, next-generation multi-object spectrographs (MOS) on 8m-class telescopes will likely out-perform similar instruments on ELTs, due to the smaller fields of view of the current ELT designs. However, there may be $D^4$ gains for medium-resolution MOS if adaptive optics can provide enhanced ‘seeing’ of $\sim0.1''$ over wide fields. New technologies such as OH-suppression fibres offer revolutionary gains, so there is a difficult balance to be achieved in applying the latest technology and having instruments ready for ELT first light.

6.7 and 12.2 GHz CH$_{3}$OH (methanol) and 22.2 GHz H$_{2}$O masers are believed to be good tracers of the earliest phases of high-mass star formation. Interferometric and VLBI (Very Long Baseline Interferometry) observations have shown that water masers are predominantly associated with the innermost portions of the jets/outflows emerging from (proto-)stellar objects. On the other hand, the astrophysical environment traced by the 6.7 GHz (and the associated 12.2 GHz) CH$_{3}$OH masers is still to be more precisely determined. So far, most high-resolution studies have focused either on CH$_{3}$OH or on H$_{2}$O masers and little is known on their connection, wehereas it would be important to study both types of maser emission in the same object. The goal of our long-term project is to perform interferometric and VLBI observations of H$_{2}$O and CH$_3$OH masers towards a selected sample of high-mass YSOs where both maser types have been detected. This work presents preliminary results obtained for a few objects of our sample, and discusses possible implications.

The population of small bodies of the outer Solar System is composed by objects of different kind and size, such as comets, Kuiper Belt objects and Centaurs, all sharing however a common characteristic, that is to be rich in ices and other volatiles. The knowledge of the composition and properties of these bodies would help in better understanding the processes that shaped the solar nebula at large heliocentric distances and determined the formation and evolution of the planets. A large number of observational results are now available on these bodies, due to successful space missions and increasingly powerful telescopes, but all our instruments are unable to probe the interiors. However, we are beginning to see how these seemingly different populations are related to each other by dynamical and genetic relationships. In this paper we try to see what could be their thermal evolution and how and when it brings to their internal differentiation. In fact, in this way we can try to foresee what should be the surface expression of their differentiation and evolution and try to link the surface properties, as probed by instruments, with the interior properties. One thing to note about the cometary activity is that it is well interpreted when assuming that the comets are small, fragile, volatile-rich and low-density objects. This view, despite of the strong differences noted in the few comet nuclei observed in situ, has not been disproved. On the other side, the observations of the Kuiper belt objects are possibly indicating that they are large, probably collisionally evolved objects (Farinella & Davis 1996), maybe with larger densities. We are now facing a kind of paradox: we have from one side the comets, and from the other side a population of much denser and larger objects; we know that a dynamical link exists between them, but how can we go from one type of population to another? In this paper the current status of our knowledge on the subject is reviewed, taking into account the results of thermal modeling and the results of observations.