We discuss the selection of blue horizontal branch stars (BHBs) using preliminary Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) color data and outline techniques for structure detection using those data. We first outline the adaptation of an old color selection for for BHBs using Sloan Digital Sky Survey (SDSS) data to the Pan-STARRS filter set. We next outline a rudimentary search algorithm designed to autonomously detect substructure in the Galactic halo. Finally we discuss preliminary results and comment on future refinements to the process.

By giving three different definitions of peak flux(original peak flux, corrected peak flux, and scaled peak flux), we analyze the frequency distributions of 14057 flares recorded by GOES from 2000 to 2005. We find a significant result that the frequency distribution of the scaled peak flux for all the sample flares can be approximated by a perfect power-law function with an index of 2.18, without any usually deviating from the power-law at the lower fluxes.

The halo masses of nearby individual elliptical galaxiescan be estimated by using the kinematics of their stars, planetary nebulae, and globularclusters–ideally in combination.With currently improving coverage of galaxies of ordinary luminosities and morphologies,systematic trends may be identified.Bright, boxy ellipticals show strong signatures of dark matter,while faint, disky ones typically do not.The former result is problematic for the MOND theory of gravity, and the latter is a challenge to explain in theΛCDM paradigm of galaxy formation.

Galaxy formation and evolution is one of the most challenging tasks in astrophysics. There is strongly increasing and substantial progress in this field not only due to the increase of telescope size and developments of new techniques providing observations allover the electromagnetic spectrum, but also the development of advanced computer architectures and of sophisticated numerical codes allow to tackle this problem from both sides and to link both research approaches to a fruitful progress in astrophysics. This review will not focus on the application of a single numerical method and the description of its result, but is instead aiming at providing an overview of different numerical tools on the basis of particle and grid schemes and to referring to important publications for the intersted reader.

The formation of resonant planets pairs in exoplanetary systems involves planetary migration inside the protoplanetary disc: an inwards migrating outer planet captures in Mean Motion Resonance an inner planet. During the migration of the resonant pair of planets, the eccentricities are expected to rise excessively, if no damping mechanism is applied on the inner planet. We express the required damping action to match the observations, and we show that the inner disk can play this role. This result applies for instance to the system GJ 876: we reproduce the observed orbital elements through a fully hydrodynamical simulation of the evolution of the resonant planets.

We analyze a sample of Swift X-ray and optical GRB afterglows which werechosen so as to reduce selection effects against the weakest events. We tentativelyidentify important differences in GRBs that show a fast decay with respect to the averageGRB, in particular a tendency for the more energetic bursts to have a steeper afterglowdecline. An explanation to this finding could be bursts in a wind environment are onaverage more energetic than bursts occurring in a constant density medium.

VIHI: the Visible and Infrared Hyperspectral Imager is one of the three channels of the Simbio-Sys instrument for the BepiColombo mission to Mercury. Its scientific objective is to study the hermean surfaces composition by sensing the photon flux reflected off the planet. VIHI works in the range of 400 to 2000 nm with a spectral resolution around a few hundreds. The particularity of this channel is the use of a single detector matrix (264 × 264) for both visible and infrared wavelengths. Getting the visible part of the detector responsivity is achieved by thinning an infrared HgCdTe matrix because visible light is completely absorbed inside the substrate. The thinning process is well controlled since a long time and was used to increase number of thermal cycle of the hybrid devices. Recently, this process is able to remove completely the substrate and, thus, open the detector to the visible range. The detector is a custom design made by Raytheon Vision System in Goleta (USA). In this paper, we will describe the expected performances of the detector which is designed to work in the very harsh radiation environment of Mercury.

The ESA space mission Gaia, planned to be launched at the end of 2013, will make astrometric, photometric and spectroscopic measurements of about 1 billion sources in our Galaxy. Amongst these sources will be numerous multiple systems. In the processing chain eclipsing binaries (EBs) will be detected and, if possible, their period and characteristics determined. Here we summarize the various steps that are foreseen to automatically classify and characterise these EBs.

The advent of 8  m class telescopes has allowed the detailed spectroscopicstudy of sizeable numbers of extremely metal-poor Galactic stars whichare the witnesses of the formation of the early Galaxy. Their chemicalcomposition displays some distinctive trends which should providea strong constraint on the physical nature of the first generation(s) ofstars and on their nucleosynthetic output. I will review recent results in the field following the periodic table, from lithium to uranium andshortly comment on the intriguing classes of Carbon Enhanced Metal Poor (CEMP) stars, for many of which there is no analogue among solar metallicity stars. In spite of these exciting results, the number of known stars of metallicity below [Fe/H] = -3.3 remains quite small and it would be desirable to discover more, both to clearly understand the metal-weak tail of Halo metallicity distribution and to clarify the abundance trends at the lowest metallicities. Most of these extremely rare objects have been discovered by the wide field objective prism surveys, HK survey and Hamburg-ESO survey.In the near future the Sloan Digital Sky Survey and its continuation SEGUE are expected to boost significantly the numbers of known extremely metal poor stars. We are living exciting times but an even more exciting futurelies ahead!

This paper discusses the opportunities at Dome C for both photometric and spectroscopic asteroseismology. Dome C has two great advantages in this field: the first is the high percentage of superbly photometric skies; the second is the opportunity for long runs, a necessary requirement for asteroseismology. The potential of Dome C for asteroseismology is compared with existing ground-based networks and a potential spectroscopic networks, as well as with space missions.

This paper analyses cosmological observations within inhomogeneous and exact solutions of the Einstein equations. In some way the analyses presented here can be freed from assumptions such as small amplitude of the density contrast.The supernova observations are analysed using the Lemaître–Tolman model and the CMB observations are analysed using the quasispherical Szekeres model.The results show that it is possible to fit the supernova datawithout the cosmological constant. However ifinhomogeneities of sizes and amplitudes as observed in the local Universeare considered, their impact on cosmological observations is small.

Both emission and absorption techniques have been developed at the AILES beamline of SOLEIL synchrotron to record far infrared (FIR) spectra of transient species. To illustrate the possibilities offered by our absorption set-up, we report in this paper new rotational transitions of the SO radical falling in the spectral range covered by the HIFI spectrometer onboard Herschel.

A review of some of the most important studies of the past several decades pertaining to the study of atomic diffusion in stellar atmospheres is presented. A brief description of various studies of radiative accelerations and diffusion calculations in stellar atmospheres is given. Several physical phenomena such as ambipolar diffusion, light-induced drift and the effect of magnetic fields on diffusion are discussed. Results from recent self-consistent model atmospheres including elemental stratification are also reviewed. Particularities of radiative acceleration calculations in stellar atmospheres as well as difficulties and future challenges related to diffusion calculations in stellar atmospheres are also presented.

The analysis of a sample of 30 isolated spiral galaxies with andwithout an Active Galactic Nucleus (AGN) results in active and control galaxies having similarbulge and disk properties. Secondary bars also seem to beindistinguishable. Circumnuclear kinematics are also analyzed todisentangle what kind of mechanisms are taking place in thecircumnuclear regions. From long slit spectra of a subsample ofisolated active and non-active spiral galaxies in the Hαemission line region, the shape and properties of the rotation curvesare obtained together with the line ratios used to estimate themetallicity of all the detected HII regions. Kinematics andmetallicities are also studied in comparison with the propertiesdetermined for a family of 111 spiral galaxies with a welldetermined environmental status, ranging from isolation to close, though not disruptive, interaction with satellites or companions. Thestellar kinematics are also studied in some cases, with as mainresult the detection of a stellar velocity dispersion drop in thecenters of four Seyfert galaxies. Together with previous findings, ourresults from the comparison between active and non-active isolatedgalaxies point to AGNs being an episode in the life of galaxies,provided that the fuel is available and the accumulation mechanismsare at work.

Based on my direct personal experience as an author, referee, editor, and PhD thesissupervisor, I present in this paper some advice and guidelines on writing scientificpapers. This article copes with the preparation of manuscripts, with the handling ofcopyrights and permissions to reproduce, with communicating with editors and referees, andwith avoiding common errors. More than two dozen FAQs are dealt with, among others: whoshould be coauthor, what is honorary authorship, how to settle the order of author names,may the list of authors change during the review process, who submits the manuscript tothe Editor, must one wait for coauthors’ consent to submit, when to submit a manuscript toastro-ph, how to communicate with the referee, with whom to share a referee report, canstudents be referee, how to cite and quote a straying paper, how to cope with writer’sblock, should others be allowed to completely rewrite a manuscript, how to review a paper,how to revise a multi-author paper, when to ask for another referee, why do Editors edit,and why do referees review?

Spectral data reduction is a crucial step, as so important as the acquisition process. Rigor shall be as well applied at this stage to not degrade the quality of the data acquired. It is the last step before the computation of the astrophysical quantities. It is thus necessary to understand what is involved in each processing steps and the underlying limitations. Thus limitations or limit conditions are usually embedded and then hidden in a specific software command that everyone use without completely mastering what is really at stake. In this chapter we will introduced the different type of processing and spectral analysis which can dispose an amateur in several software packages. The first processing will treat about basic images correction which are linked to the CCD acquisition and the processes pipeline. We will then describe the different strategy to calibrate the spectral profile in wavelength and the few corrections driven by the earth environment to increase the accuracy of the future measurements. We will end with the description of few tools on quantitative spectral analysis and their limitations. The practice of spectral acquisition and processing is just at its beginning in amateur world. We hope that this section will demystify the essential step of spectral processing and will motivate the amateur to go beyond the contemplative watching of sky wonders.

Important progress has been made within the past few years regardingthe theory of low mass stars (m < 1 M⊙) and brown dwarfs(m < 0.075 M⊙).The main improvements concern the equation of state of dense plasmasand the modelling of cool and dense atmospheres,necessary for a correct description of such objects. Thesetheoretical efforts now yield a better understanding of these objectsand good agreement with observations regarding colour-magnitudediagrams of globular clusters, mass-magnitude relationshipsand near-IR colour-magnitude diagrams for openclusters. However uncertainties still remain regardingsynthetic optical colours and the complex problemof dust formation in the coolest atmosphere models.We will present a review of the current success and uncertaintiesof the theory of these objects, which may guide forthcoming projectswith GAIA.

We report on spectropolarimetric observations of 7 A-type supergiantstaken with the MuSiCoS echelle spectropolarimeter mounted at the 2 m Bernard Lyot telescope at the Pic du Midi, during June-July 1999 and June-July 2002. We present the values of the derived longitudinal component of the magnetic field. The significance of the results isdiscussed.

Spectral surveys provide the only way to determine the full molecular inventory of a source and hence to build a comprehensive view of the state of the molecular gas and its role in the star formation process. Systematic studies have opened the possibility of using chemistry as a diagnostic tool for star burst and AGN activities in the highly obscured galactic nuclear regions.

Here we present the results of a 3 mm survey of 23 galaxies, obtained with the EMIRreceiver at the IRAM 30 m telescope. Emission of the main molecular species is comparedwith existing chemical models, in order to find and test molecular signatures of galaxyevolution and to compare them to IR evolutionary tracers.