An all-sky list of 88 nearby dwarf spheroidal (dSph) galaxies with distances $D < 10$ Mpc is considered. Most of the objects have recently been found by Karachentseva & Karachentsev based on POSSII/ESO-SERC survey. A hundred more dSph galaxies are expected in this volume, being missed so far because of their low luminosity and low surface brightness. Apart from 22 dSph members of the Local Group, there are 33 dSphs in other nearby groups that have been resolved recently into stars with HST. Only 5% of the local dSphs are situated outside the known groups.

We discuss observational correlation between basic parameters of the dwarf spheroidal galaxies, in particular, absolute magnitude, surface brightness, metallicity, and so-called “tidal index”. The observed number of dSphs in group increases with luminosity of its brightest galaxy. In a “synthetic” nearby group, dwarf spheroidal galaxies are distributed in depth quite symmetrically about the principal galaxy, having an rms distance scatter of 200 kpc. Projected radial distribution of dSphs in the synthetic group follows the profile $N(R) ~ exp(-R/200$ kpc).

We present new FUSE and HST/STIS observations of two high Galactic latitude AGN that we use to measure the nuclear wind velocity of the Milky Way for the first time. We find high velocity C III & O VI at a heliocentric velocity of $+163 \pm 8 {\rm km s^{-1}}$ and C III & N V at $-105 \pm 14 {\rm km s^{-1}}$ toward PKS 2005–489 ($l=350^{\circ}, b=-33^{\circ}$) and C III, C IV, & Si IV and C III & O VI toward Mrk 1383 ($l=349^{\circ}, b=55^{\circ}$) at $+48 \pm 4 {\rm km s^{-1}}$ and $+94 \pm 7 {\rm km s^{-1}}$, respectively. We have estimated the Galactocentric escape velocity of gas above the Galactic Centre along the PKS 2005–489 and Mrk 1383 sight-lines to be $\geq\,$$215 \pm 35$ and $\geq\,$$145 \pm 25 {\rm km s^{-1}}$, respectively. Thus, we have detected both infalling and bound outflowing gas from the Galactic Centre, indicating that the Milky Way does not produce a starburst wind, but a bound Galactic “fountain” instead.

There seems to be no consensus on the [O/Fe] values found in metal-poor stars nor their trend with metallicity: different indicators give different results. We present here [O/Fe] derived from three different oxygen abundance indicators ([OI], OI and OH UV lines) for a sample of thirteen subgiant stars with metallicities in the range $-3\le\mathrm{[Fe/H]\le-1.5$. Oxygen and iron abundances were determined from the analysis of high $S/N$ spectra acquired with the UVES spectrograph at VLT. We found good agreement between [O/Fe] estimates based on OH and the estimates based on [Oi] ($\mathrm{mean\ difference}\sim-0.09\pm0.25(\mathrm{s.d.})$), although the scatter is not insignificant. Unfortunately, good agreement is not reached for the third indicator ($\mathrm{mean\difference}\sim0.19\pm0.22(\mathrm{s.d.})$). Our [OI] and OH-based estimates do not show a well defined linear trend with metallicity. Another interesting result is that the abundances based on molecular lines ($\mathrm{[O/Fe]}\sim0.45$) are in general lower than previous published results for turn-off stars even though a lower solar oxygen abundance ($A(\mathrm{O})=8.74$) was assumed.

As the nearest galaxies around us, the Local Group systems offer especially good opportunities for observations of their nuclear X-ray radiation. Certain or possible nuclear X-ray sources in the Local Group suggest a minimum luminosity for activity to become manifest.

An account of a free-ranging Panel Discussion held during the Symposium.

In the last triennium two International Schools for Young Astronomers took place in 2004 and 2005, respectively in Morocco and Mexico.

This article reviews the popular reasons for the belief that dwarf elliptical galaxies and (ordinary) elliptical galaxies are distinct and separate species. They include: light–profile shape (or similarly image concentration); the magnitude–central surface brightness diagram; the magnitude–effective surface brightness diagram (or similarly the magnitude–effective radius diagram); and the Fundamental Plane. It is shown how a continuous trend between luminosity and a) light–profile shape, and b) central surface brightness (until the onest of core formation at $M_B \sim -20.5$ mag), results in a unification of the dwarf elliptical and (ordinary) elliptical galaxies. Neither the above four reasons, nor the luminosity function (at least in the Virgo cluster) provide evidence for a division at $M_B=-18$ mag between the dwarf elliptical and (ordinary) elliptical galaxies. Instead, they appear to be continuous extensions of each other.

A forthcoming step in the study of extrasolar planetary systems is the direct detection and characterization of Earth-like planets. An asset of the ELTs in that context is their very high angular resolution and their collecting area. The luminosity ratio between a terrestrial planet and its star ($10^{-10}$) is such an ambitious goal that a thorough study needs to be carried out. We started with a simple analysis of the fundamental limitations for the detection of extraterrestrial planets with ELTs. Here, we considered an extreme adaptive optics device upstream of a perfect coronagraph. Even with high Strehl ratios, the coronagraphic halo level is only $10^{-6}$ to $10^{-7}$ at typical exo-Earth angular distances. A calibration device is therefore mandatory to reach the contrast between a terrestrial planet and its star in the near infra-red. We considered a simple but realistic model taking into account dynamic aberrations left uncorrected by the adaptive optics system, static aberrations of optical system and differential static aberrations due to the calibration channel itself. Numerical simulations prove that, after the calibration, the limitations are set by the static aberrations which cannot be neglected anymore.

Visible Nulling Coronagraphy (VNC) is the proposed method of detecting and characterizing exo-solar Jovian planets (null depth $10^{-9}$) for the proposed NASA's Extrasolar Planetary Imaging Coronagraph (EPIC) Clampin & Lyon 2004 and is an approach under evaluation for NASA's Terrestrial Planet Finder (TPF) mission. The VNC approach uses a single unobscured filled-aperture telescope and splits, via a 50:50 beamsplitter, its re-imaged pupil into two paths within a Mach-Zender interferometer. An achromatic PI phase shift is imposed onto one beam path and the two paths are laterally sheared with respect to each other. The two beams are recombined at a second 50:50 beamsplitter. The net effect is that the on axis (stellar) light is transmitted out of the bright interferometer arm while the off-axis (planetary) light is transmitted out of the nulled interferometer arm. The bright output is used for fine pointing control and coarse wavefront control. The nulled output is relayed to the science camera for science imagery and fine wavefront control. The actual transmission pattern, projected on the sky, follows a $\theta^2$ pattern for a single shear, $\theta^4$ for a double shear, with the spacing of the successive maxima proportional to the inverse of the relative lateral shear. Combinations of shears and spacecraft rolls build up the spatial frequency content of the sky transmission pattern in the same manner as imaging interferometer builds up the spatial frequency content of the image.

The Program Group for the World-wide Development of Astronomy (PGWWDA) is one of nine Comm. 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 PGWWDA, 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.

We report the results from an homogeneous analysis of the X-ray (ACIS-S/Chandra) data available for a sample of 52 LINER galaxies. The X-ray morphology has been classified attending to their nuclear compactness in the hard band (4.5–8.0 keV), into 2 categories: AGN-like nuclei (with a clearly identified unresolved nuclear source) and Starburst-like nuclei (without a clear nuclear source). 60% of the total sample are classified as AGNs, with a median luminosity of $\rm{L_{X}(2.0\hbox{-}10.0 keV)=2.5\times 10^{40} erg s^{-1}}$, which is an order of magnitude higher than that for SB-like nuclei. The spectral fitting allows to conclude that most of the objects need a non-negligible thermal contribution. When no spectral fitting can be performed (low signal-to-noise ratio), the Color-Color diagrams allow us to compute physical parameters such as density column, temperature of the thermal model or spectral index and therefore to analyze the origin of the X-ray emission. All X-ray morphology, spectral fitting and Color-Color diagrams allow conclude that a high percentage of LINER galaxies host AGN nuclei.

A colour analysis of a carefully selected sample of over 200 Virgo cluster dEs and 8 giant ellipticals (Es) in the SDSS yields the following results: a) the nucleated dEs (dENs) follow a tight colour-magnitude relation (CMR) which does not broaden significantly at fainter ($M_r \ge -15$) magnitudes, b) the CMR of dENs smoothly transitions to the CMR of Es, but the latter changes its slope at about $M_r \approx -20$, c) the brighter dENs are consistent with ages of $t \ge 5\rm{Gyr}$ and a decrease of metallicity towards fainter magnitudes, but a possible additional luminosity-age relation is not ruled out, d) it is crucial to treat dS0s separately from dEs since their different colour properties would otherwise bias the comparison of nucleated and non-nucleated dEs (dEnoNs), e) the dEnoNs show a weak trend towards bluer colours than dENs.

We find evidence for dust in the intervening QSO absorbers from the spectra of QSOs in the Sloan Digital Sky Survey Data Release 1. No evidence is found for the 2175 Å feature which is present in the Milky Way dust extinction curve.

We have derived abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Ni and Ba for 43 metal-poor field stars, mostly stars at the turn-off point and on the subgiant branch, in the interval ${-}3.0{<}$[Fe/H]${<}{-}0.4$. The analysis is differential relative to the Sun. Oxygen abundances, with consideration of NLTE effects, were derived from the OI 777.4 nm triplet lines. We find [O/Fe] to gradually increase with decreasing [Fe/H], though considerably slower than has earlier been obtained from OH lines in the UV. A scatter in [O,Mg,Ca,Ti/Fe] at a given [Fe/H] is found and we argue that this scatter is partly real. The deviations from the mean trends of abundance ratios vs [Fe/H] are found to correlate in non-trivial ways for different abundances. Similar trends are found from results of accurate studies by other groups. This seems to give further evidence for the hypothesis that the stars once formed in different subsystems, with different star-formation rates.

The paper is in press in A&A, may be obtained as astro-ph/0505118.

In order to detect directly faint planets around other stars it is important to develop techniques to cancel the central starlight. We report progress in terms of null depth on the visible nulling experiments at JPL, essential for NASAs future space missions as well as for an upcoming sounding rocket based experiment. A level of 1 Million to 1 nulling ratio (1e-6 rejection ratio) has been obtained for the first time for visible laser light, and a level of 100000 to 1 nulling ratio has been obtained for a relatively large (5%) bandpass at 650nm. Using a combination of a fiber array and deformable mirror a null of 1e-6 would correspond to a contrast of 1e-9 at a distance of 2-3$\lambda$ in the airy disk plane, only 10x away from TPFs goal. The configuration used was a fiber fed Mach Zender type interferometer, using 2 or 3 mirrors in each two arm, placed in an enclosed air container. For broadband light we used tilted dispersion glass plates in the nuller arms and an avalanche photon diode module to cover the large dynamic range. We describe a variety of conditions that have to be met and optimized to reach very deep nulls and sub-nanometer optical path difference stability, such as optical alignment, symmetry in the two arms, mechanical stability and vibration isolation.

A software for simulations of observations with an Integral Field Spectrograph attached to an extreme adaptive optics system is presented here. This code, written in IDL, has been conceived within the CHEOPS project, a second generation “Planet Finder” instrument for ESO's VLT, and it has been successfully extended to the case of various ELTs in order to test the capabilities in detecting planets of an instrument based on Integral Field Spectroscopy (IFS). We present here, beside a general description of the procedure adopted to simulate IFS observations, a set of significant simulations of detections using OWL for different kinds of planets, in order to understand which objects are the best targets for an IFS-Planet Finder mounted on a 100m-class telescope.

The Working Group on Communicating Astronomy with the Public is under Division XII - Union-Wide Activities. Formed in early 2004, this Working Group has been very active in establishing itself and promoting its core goals.

We present two new phase mask coronagraphs implemented with subwavelength diffractive optical elements. The first one is an evolution of the four quadrant phase mask coronagraph (FQPM), which resolves the $\pi$ phase shift chromaticity issue: the four quadrant zeroth order grating (4QZOG). The second one is a totally new design consisting of an optical vortex induced by a space-variant grating: the annular groove phase mask (AGPM) coronagraph is fully symmetric and free from any “shaded zones”. The potential performances of the 4QZOG and AGPM coronagraph are very good, ensuring, for instance, a theoretical contrast of $1.4 \times 10^{-7}$ at 3$\lambda/D$ over the whole K band. These coronagraphs could be used alone on single-pupil telescopes either in space or on the ground (with an adaptive optics system) to detect exoplanets.

White dwarfs are excellent targets for direct imaging searches for extra-solar planets, since they are up to $10^4$ times fainter than their main sequence progenitors, providing a huge gain in the contrast problem. In addition, the orbits of planetary companions that lie beyond the maximum extent of the Red Giant envelope are expected to widen considerably, improving resolution and further encouraging direct detection. We discuss current searches for planetary companions to white dwarfs, including our own “DODO” programme. At the time of writing, no planetary companion to a white dwarf has been detected. The most sensitive searches have been capable of detecting companions ${\gtrsim}5$M$_{\rm Jup}$, and their non-detection is consistent with the conclusions of McCarthy & Zuckerman (2004), that no more than 3% of stars harbour 5–10M$_{\rm Jup}$ planets at orbits between 75–300AU. Extremely Large Telescopes are required to enable deeper searches sensitive to lower mass planets, and to provide larger target samples including more distant and older white dwarfs. ELTs will also enable spectroscopic follow-up for any resolved planets, and follow-up of any planetary companions discovered astrometrically by GAIA and SIM.

There has been a renewed interest in searching for diffuse interstellar bands (DIBs) due to their probable connection to organic molecules and, thus, their possible link to life in the Universe. Our group is undertaking an extensive search for DIBs in DLAs via QSO absorption-line systems. Six of our DLA targets are presented here. Our equivalent width (EW) limits for the $\lambda$5780 DIB line strongly suggest that DIB abundance is below the Milky Way expected value or that metallicity plays a large role in DIB strengths.