Humans have a need to understand where they fit in the cosmos. Driven by the unlimited possibilities of human imagination the night sky has been and is one of the most powerful stimulators of curiosity. In pre-modern times, farmers, pastoralists, travelers, even city dwellers unhampered by light pollution, had many opportunities to observe and wonder on the mysteries of the starry night. In this, the International Year of Astronomy marking the 400th anniversary of Galileo's telescopic observations (that is also the 200th anniversary of the birth of Charles Darwin) there are many explorations using the advanced and expensive instruments that society provides for satisfying the public curiosity and, of course, that of the astronomers trained to ask and answer the questions. However, it is a truism that scientific answers always raise new questions that could not have been asked raised prior to the preceding answers. The more we know the more we know about what we do not know; the task of scientific inquiry, or, for that matter, inquiry in general, is endless.

The results of the analysis of the spectra of comets 9P/Tempel 1, 37P/Forbes and C/2004 Q2 (Machholz) observed in 2004-2005 at Observatório do Pico dos Dias (Brazil), and at Mount Pastukhov (SAO, Russia) are presented.

Accurate characterization of the astrometric errors in the forthcoming Gaia catalogue is essential for making optimal use of the data. Using small-scale numerical simulations of the astrometric solution, we investigate the expected spatial correlation between the astrometric errors of stars as function of their angular separation. Extrapolating to the full-scale solution for the final Gaia catalogue, we find that the expected correlations are generally very small, but could reach some fraction of a percent for angular separations smaller than about one degree. The spatial correlation length is related to the size of the field of view of Gaia, while the maximum correlation coefficient is related to the mean number of stars present in the field at any time. Our scalable simulation tool (AGISLab) makes it possible to characterize the astrometric errors and correlations, e.g., as functions of position and magnitude.

We present selected results from an investigation that is currently underway to determine the abundances of the Fe group elements in early B stars and assess the extent to which contemporary NLTE and LTE models represent their atmospheres. High resolution UV and optical spectra of B stars that display ultrasharp lines are compared with computations from TLUSTY/SYNSPEC and SYNTHE. Some results from our analysis of the abundance standard ι Her (B3V) are presented here.

We have measured the velocity dispersion of the Galactic globular cluster NGC 2419 to determine if a substantial amount of dark matter is present in this cluster. NGC 2419 is one of the best globular clusters to look for dark matter due to its large mass, long relaxation time and large Galactocentric distance, which makes tidal stripping of dark matter unlikely. Our results can be summarized as follows. (i) We found a global velocity dispersion of 4.14 ± 0.48 km s−1, which leads to a total cluster mass of (9.02 ± 2.22) × 105 M⊙ and implies a global mass-to-light ratio of 2.05 ± 0.50 M⊙/L⊙. (ii) Our derived mass-to-light ratio is completely consistent with the mass-to-light ratio of a standard stellar population at the metallicity and age of NGC 2419. In addition, the mass-to-light ratio of NGC 2419 does not increase towards the outer cluster parts. (iii) We can therefore rule out the presence of a dark-matter halo with a central density greater than about 0.02 M⊙ pc−3. Similar limits are found for other halo globular clusters, like Pal 14. These observations therefore indicate that NGC 2419 and other halo globular clusters did not form at the centers of dark-matter halos similar to those surrounding dwarf galaxies. Instead, an origin driven by gas-dynamical processes during mergers between galaxies or proto-galactic fragments seems to be the more likely explanation for the formation of even the lowest-metallicity globular clusters.

The study of stellar populations in galaxies is entering a new era with the availability of large and high-quality data bases of both observed galactic spectra and state-of-the-art evolutionary synthesis models. The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) has a 4m primary, and a 5 degree field of view, accommodate as many as 4000 optical fibers. It can obtain the spectra of objects as faint as down to B = 20.5 mag with an exposure of 1.5 hour, promising a very high spectrum acquiring rate of ten-thousands of spectra per night. In this talk, we introduce the progress of the LAMOST project, its surveys and show the spectral synthesis code that we are developing for the LAMOST ExtraGAlactic Surveys (LEGAS).

Quasi–periodic pulsations in various wavebands are natural manifestations of emission of stellar flares. We suggest a diagnostic tool of stellar flares based on the coronal seismology and the solar–stellar analogy. Two approaches are used: (I) flare loop as a resonator for MHD oscillations and (II) flare loop as an equivalent electric circuit. Using optical, X–ray, and radio data we obtained flare plasma parameters for the red dwarfs EQ Peg, AT Mic, and AD Leo. The characteristic length of stellar flare loops l ~ R* and their electric currents turned out to be one–two orders of magnitude lager than the solar ones. Advantages of proposed diagnostics in comparison to the scaling law methods are given.

Observations of light elements in hot massive stars are limited to few transitions of boron in the satellite-ultraviolet; lithium and beryllium are not observable at all. But because of its high sensitivity to the effects of rotational mixing, boron abundance determinations in massive stars have excelled as the definite test for evolutionary models with rotation. In this paper the observational evidence for rotational mixing in massive stars is reviewed and alternative interpretations are discussed.

The model of Schönrich & Binney (2009) offers new ways to understand the chemo-kinematic structure of the solar neighbourhood in the light of radial mixing. The combination of chemical information with rich kinematic data reveals a still hardly explored abundance of interconnections and structures from which we can learn about both the physics and history of our Galaxy. Large upcoming datasets can be used to improve estimates of central parameters, to shed light on the Galaxy's history and to explore the unexpected way of understanding the well-known division of the Galactic disc yielded by the new model.

Active galactic nuclei can be identified in deep HST surveys using different selection techniques and multiwavelength data. We aim to produce a complete sample of AGN in the GOODS South and North fields by combining X-ray, optical and mid-IR selection criteria, including galaxies displaying nuclear optical variability.

We are reporting some recent results from our long-term program aimed at characterizing the obscured present-day star cluster population in the Galaxy. Our goal is to expand the current census of the Milky Way's inner stellar disk to guide models seeking to understand the structure and recent star-formation history of our Galaxy. The immediate goal is to derive accurate cluster physical parameters using precise infrared photometry and spectroscopy. So far, we observed approximately 60 star cluster candidates selected from different infrared catalogs. Their nature, reddening, distance, age and mass are analyzed. Two of them, Mercer 3 and Mercer 5, are new obscured Milky Way globular clusters. Among the newly identified open clusters, the objects [DBS2003] 179, Mercer 23, Mercer 30, Mercer 70, and [DBS2003] 106 are particularly interesting because they contain massive young OB and Wolf–Rayet stars with strong emission lines.

In this talk I shall try to highlight some themes that seem to promise specially interesting progress in the coming decades. I can't claim to be much of a prophet myself, but I'd like to recall someone who was: Arthur C. Clarke. He lived in Sri Lanka, and died in 2007, aged 90. I'd like to discuss three issues that he would have found interesting: space and alien life; galaxies and their origin; and (more speculatively) the size of our universe.

We give an overview of the science case for spectroscopy of resolved stellar populations beyond the Local Group with the European Extremely Large Telescope (E-ELT). In particular, we present science simulations undertaken as part of the EAGLE Phase A design study for a multi–integral-field-unit, near-infrared spectrograph. EAGLE will exploit the unprecedented primary aperture of the E-ELT to deliver AO-corrected spectroscopy across a large (38.5 arcmin2) field, truly revolutionising our view of stellar populations in the Local Volume.

Photographic and photoelectric observations of comet 1P/Halley's ionised gas coma from CO+ at 4,250 Å and neutral gas coma from CN at 3,880 Å were part of the Bochum Halley Monitoring Program, conducted at the European Southern Observatory, La Silla, Chile, from February 17 to April 17, 1986.

In this spectral range it is possible to see the continuum formation, motion and expansion of plasma and neutral gas structures. To observe the morphology of these structures, 32 CO+ photos (glass plates) from comet 1P/Halley obtained by means of an interference filter have been analysed. They have a field of view of 28.6 × 28.6 degrees and were obtained from March 29 to April 17, 1986 with exposure times between 20 and 120 minutes.

All photos were digitised with a PDS 2020 GM microdensitometer. After digitisation, the data were reduced to relative intensities, and those with proper calibrations were also converted to absolute intensities, expressed in terms of column densities. The CO+ absolute intensity values still contain the continuum intensity. To calculate the CO+ column density it is necessary to subtract this continuum intensity.

The relations between CO+ and CN in average column density values (NCO+/NCN) are 11.6 for a circular diaphragm with average diameter (Φ) of 6.1 arcminutes which corresponds to a distance from the nucleus (ρ) equal to 6.3 × 104 km; 20.0 for Φ = 7.1 arcminutes and ρ = 7.3 × 104 km; 8.1 for Φ = 8.5 arcminutes and ρ = 8.7 × 104 km; 35.6 for Φ = 11.9 arcminutes and ρ = 1.2 × 105 km; and 31.3 for Φ = 16.7 arcminutes and ρ = 1.7 × 105 km. These values are in perfect agreement with the data for short distances (ρ from 3.9 × 103 to 1.2 × 104 km) and small slit diameters (Φ from 0.4 to 1.2 arcminutes).

With the use of diaphragms with large diameters it is possible to get some information about the outer coma of the comet (in this paper, from 60,000 until 170,000 km away from the nucleus). At these distances, the CO+ column density changes only due to the geometrical dilution, because the CO+ parent molecules are already photoionised or photodissociated.

It has been known for some time that elliptical galaxies have some form of dust structure at their centers (Kormendy & Djorgovski 1989; van Dokkum & Franx 1995). Nevertheless the exact amount and the origin of the dust is still unknown. In a previous paper, we have shown that all early-type galaxies hosting an AGN have dust at their centers as opposed to only a quarter of the inactive galaxies in a pair-matched sample (Simões Lopes et al. 2007). Here we use Spitzer (IRAC and MIPS) observations of the same sample — 32 active and 32 inactive early-type galaxies — and state-of-the-art spectral modelling from Draine & Li (2007) to estimate the dust mass present in these galaxies. We have also created PAH images by estimating and subtracting the stellar-only contribution to the flux at the 7.9 μm image from the 3.6 μm image.

We combine results from interferometry, asteroseismology and spectroscopic analyses to determine accurate fundamental parameters (mass, radius and effective temperature) of 10 bright solar-type stars covering the H-R diagram from spectral type F5 to K1. Using “direct” techniques that are only weakly model-dependent we determine the mass, radius and effective temperature. We demonstrate that model-dependent or “indirect” methods can be reliably used even for relatively faint single stars for which direct methods are not applicable. This is important for the characterization of the targets of the CoRoT and Kepler space missions.

We analyze a sample of 21 super-metal-rich (SMR) stars, using high-resolution échelle spectra obtained with the FEROS Spectrograph at the 1.5m ESO telescope. The metallicities are in the range 0.15 < [Fe/H] < 0.5, 3 of them in common with Pompéia et al. (2002). Geneva photometry, astrometric data from Hipparcos, and radial velocities from CORAVEL are available for these stars. The peculiar kinematics suggests the thin disk close to the bulge as the probable birthplace of these stars (Grenon 1999). From Hipparcos data, it appears that the turnoff of this population indicates an age of 10-11 Gyr (Grenon 1999). Detailed analysis of the sample stars is carried out. Lithium abundances of these stars were derived, and their behaviour with effective temperature is shown.

We have analyzed the shape of the solar corona using the data of daily observations with Mark-3/4 (1980-2008) and SOHO/Lasco-2 (1996–2008) telescopes. The angles of deviation of coronal rays from the radial direction Δθ vary cyclically, reaching the maximum deviation towards the solar equator at the minimum of the solar activity. At the minimum of the 24-th cycle of activity, the Δθ angles were smaller than they were at the minimum of the 22-nd and 23-rd cycles.

We also analyzed of the solar structure corona during eclipses for minimum activity from 1870 till 2008. We examined changes in the index, which characterizes the angle of large coronal streamers to the equatorial plane. It has been shown that the index has been smoothly changing during the last 140 years. The maximal value of an index was during 17–19 activity cycles. The minimal values are reached in the end of 19 centuries and at the present time.

We consider the relations between the angles of deviation of coronal rays at the minimum of activity, the parameters of the global magnetic field of the Sun, and the amplitude of the subsequent cycle of activity, and discuss the hypothesis that the variations of the inclination of coronal rays may affect the parameters of the solar wind and the indices of geomagnetic perturbations at the minima of the solar activity cycles.

In the recent years, more and more sophisticated models have been proposed for the gas distribution and kinematics in the Milky Way, taking into account the main bar, but also the possible nuclear bar, with the same or different pattern-speed. I review the success and problems encountered by the models, in particular in view of the new discovery of a symmetrical far-side counterpart of the 3 kpc arm. The inner part, dominated by the bar, and the outer parts, dominated by the spiral arms, can be observed from a virtual solar position, and the errors coming from kinematical distances are evaluated. The appearance of four arms could be due to a deprojection bias.

We present in the following some capabilities of the Gaia mission for performing local test of General Relativity (GR) based on the astrometry of asteroids. This ESA cornerstone mission, to be launched in Spring 2012, will observe—in addition to the stars and QSOs—a large number of small solar system bodies with unprecedented photometric and, mostly, astrometric precisions. Indeed, it is expected that about 250,000 asteroids will be observed with a nominal precision ranging from a few milli-arcsecond (mas), to sub-mas precision, depending on the target's brightness. While the majority of this sample is constituted of known main-belt asteroids orbiting between Mars and Jupiter, a substantial fraction will be made of near-Earth objects, and possibly some newly discovered inner-Earth or co-orbital objects.

Here we show the results obtained from a simulation of Gaia observations for local tests of GR in the gravitational field of the Sun. The simulation takes into account the time sequences and geometry of the observations that are particular to Gaia observations of solar system objects, as well as the instrument sensitivity and photon noise. We show the results from a variance analysis for the nominal precision of the joint determination of the solar quadrupole J2 and the PPN parameter β. Additionally we include the link of the dynamical reference frame to the conventional kinematically non-rotating reference frame (as obtained in the visible wavelength by Gaia observations of QSOs). The study is completed by the determination of a possible variation of the gravitational constant /G, and deviation from Newtonian 1/r2 gravitational law. Comparisons to the results obtained from other techniques are also given.