The coronal mass ejection (CME) link to geomagnetic storms stems from the southward component of the interplanetary magnetic field contained in the CME flux ropes and in the sheath between the flux rope and the CME-driven shock. A typical storm-causing CME is characterized by (i) high speed, (ii) large angular width (mostly halos and partial halos), and (iii) solar source location close to the central meridian. For CMEs originating at larger central meridian distances, the storms are mainly caused by the sheath field. Both the magnetic and energy contents of the storm-producing CMEs can be traced to the magnetic structure of active regions and the free energy stored in them.

New Horizons is a NASA mission to explore the Pluto system and the Kuiper Belt. The spacecraft was launched on 19 January 2006 and will begin its encounter studies of Pluto in early 2015, culminating on 14 July 2015 with a close approach just 12,500 km from Pluto. The spacecraft carries panchromatic and color images, IR and UV mapping spectrometers, a radio science package, two in situ plasma instruments, and a dust counter. We describe the capabilities of this instrument suite and the spacecraft, the observations planned for Pluto and its system of satellites, and our plans for KBO flybys to take place late in the 2010s.

The stellar populations of 849 local infrared-selected galaxies from SDSS and IRAS (including 419 star-forming galaxies, 326 composite galaxies, 35 Seyfert 2s, and 69 LINERs in 4 spectral classes) are studied by using STARLIGHT. Among the 4 spectral classes, the importance of young populations decreases from star-forming, composite, Seyfert 2 to LINER; and Seyfert 2 and LINER are more metal-rich; ULIGs (ultra luminous infrared galaxies) & LIGs present the youngest populations among 3 infrared luminosity bins; and normal galaxies are more metal-rich. The dominant contributors to masses are all old populations.

The cosmic abundance of lithium continues to represent a conundrum, as predictions from BBN theory are inconsistent with measurements in the atmospheres of the lowest-metallicity stars. While there are worries that modifications of the stellar Li abundances may play a role in this discrepancy, no satisfactory solution has yet been found. We suggest an alternate approach to studying the cosmic abundance of Li: measurements of interstellar gas-phase Li in low-metallicity environments.

We present the results of a study of the very high velocity (υrad = +448.0 ± 1.0 kms−1) low-metallicity ([Fe/H] = −1.93) star Feh-Duf ((Fehrenbach & Duflot 1981) showing peculiar chemical abundance. Using high-resolution spectrum, we showed that this star has enhanced carbon and heavy s-process element abundance ([C/Fe] = +0.58, [hs/Fe] = +0.88 dex) while the [Y/Fe] = −0.07 dex). The carbon isotopic ratio is low (12C/13C=8). We found that oxygen abundance is reduced ([O/Fe] = +0.10 dex) as compared with Galactic field stars of a similar metallicity. The evolution state of this star and its possible extragalactic origin are discussed.

The principles and advantages of torus modelling are explained.

We obtained deep images for 49 Seyfert 2 galaxies in 6 infrared bands: J, H, K, L, M, and N with the VLT at Paranal, the NTT at La Silla, and Gemini at Pachón, to compile their nuclear infrared (IR) spectral energy distributions (SEDs). These galaxies were extracted from the Extended 12 μm Galaxy Sample (Rush et al. 1993).

Human beings are born astronomers. Ever since they learnt to walk upright they have looked at the sky and wondered. The sky has remained the same but not its meaning. We can distinguish between three phases in the history of humankind's relationship with its cosmic environment: (i) propitiatory phase; (ii) negotiatory phase; and the current (iii) sky-as-an-object explanatory, phase. My concern here is to discuss the interplay between astronomy and culture in general in the Indian context. Much of the discussion belongs to the negotiatory phase. More specifically I discuss how in the formative era, sacred texts influenced astronomy, how these texts themselves were modified under the influence of new scientific developments, and how mythology was upgraded to keep pace with science.

We describe the behavior of the rotational velocity in metal-poor stars ([Fe/H] ~ −0.5 dex) at different evolutionary stages, based on v sin i values from the literature. Our sample is composed of stars in the field and in some Galactic globular clusters, including stars on the main sequence (MS), red-giant branch (RGB), and horizontal branch (HB). The metal-poor stars are mainly slow rotators, and their v sin i distribution along the Hertzsprung–Russell diagram is quite homogeneous. Nevertheless, a few moderate to high values of v sin i are found for stars located on the MS and the HB. We show that the overall distribution of v sin i values is basically independent of metallicity for the stars in our sample. In particular, the fast-rotating MS stars in our sample exhibit similar rotation rates as their metal-rich counterparts, suggesting that some may actually be fairly young, in spite of their low metallicity, or else that at least some would be better classified as blue straggler stars. We do not find significant evidence of evolution in v sin i values as a function of position on the RGB. In particular, we do not confirm previous suggestions that stars close to the RGB tip rotate faster than their less-evolved counterparts. While the presence of fast rotators among moderately cool blue-HB stars has been suggested as due to angular-momentum transport from a stellar core that has retained significant angular momentum during its prior evolution, we find that any such transport mechanisms must likely operate very fast as the star arrives on the zero-age HB (ZAHB), since we do not find a link between evolution off the ZAHB and v sin i values.

The SIM Lite Observatory is expected to provide a global astrometric reference frame surpassing the 1-μas accuracy threshold in some spherical harmonics. A range of time-varying physical distortions of the reference frame will become observable as large-scale perturbations of the proper motion field. I consider the main sources of the apparent and physical motion of reference objects, such as the aberration of light caused by the acceleration of SIM, long gravitational waves and hypothetical rotation of the Universe, and present some estimates of the astrometric sensitivity to these effects. I argue that a global solution and covariance analysis is of crucial importance for the SIM mission to differentiate the inevitable accidental and systematic zonal errors from real physical phenomena.

Babylonian astronomy is quite different from astronomy as it is customary today. We have to reconstruct it exclusively from texts and a few schematic drawings accompanying them. No instruments related to astronomy have been found. These texts are written on clay tablets in cuneiform script which was used in the Near East from ca. 3000 BCE to 100. It was completely forgotten and only deciphered in the middle of the 19th century. Since then, hundreds of thousands of clay tablets have been found in archaeological excavations, mostly in present-day Iraq. Among these are a few thousand tablets related to astronomy. Many have been published, but more still need to be worked on. And of course an unknown number of such texts is still buried under the sands of Iraq.

In March 2004 the European Space Agency launched its Planetary Cornerstone Mission Rosetta to rendezvous with Jupiter-family comet 67P/Churyumov-Gerasimenko. The Rosetta mission represents the next step into the improvement of our understanding of comet nuclei naturally following the four successful comet nucleus fly-by missions carried out in the past. It will however not perform a simple fly-by at its target comet, but combines an Orbiter and a Lander Mission. The Rosetta spacecraft will go in orbit around the comet nucleus when it is still far away from the Sun, and escort the comet for more than a year along its pre- and post-perihelion orbit while monitoring the evolution of the nucleus and the coma as a function of increasing and decreasing solar flux input. Different instrumentations will be used in parallel, from multi-wavelength spectrometry to in-situ measurements of coma and nucleus composition and physical properties. In addition the Rosetta Lander Philae will land on the nucleus surface, before the comet is too active to permit such a landing (i.e. at around r = 3 AU) and examine the surface and subsurface composition as well as its physical properties. Two fly-bys at main belt asteroids have been scheduled for the Rosetta spacecraft during its journey to the comet. The first fly-by at E-type asteroid (2867) Steins was already successfully executed in September 2008. The second and main fly-by at asteroid (21) Lutetia is scheduled for July 2010.

Global warming in the troposphere and the decrease of stratospheric ozone concentration has become a major concern to the scientific community. The increase in greenhouse gases and aerosols concentration is believed to be the main cause of this global change in the lower atmosphere and in stratospheric ozone, which is corresponded by a cooling in the middle and upper atmosphere. However, there are natural sources, such as the sun and volcanic eruptions, with the same ability to produce global changes in the atmosphere. The present work will focus on solar variation and its signature in lower and middle atmosphere parameters. The Sun can influence the Earth and its climate through electromagnetic radiation variations and also through changes in the solar wind which causes geomagnetic storms. The effects of both mechanisms over the lower and middle atmosphere and ozone layer will be discussed through an overview of selected papers, which by no means cover this subject that is extremely wide and complex. A fundamental understanding of the atmosphere response to solar variations is required for understanding and interpreting the causes of atmospheric variability. This is an essential focus of climate science, which is seeking to determine the extent to which human activities are altering the planetary energy balance through the emission of greenhouse gases and pollutants.

We study the fragmentation of expanding shells in the context of the linear thin-shell analysis. We simulate shell fragmentation using the flash AMR code and a variant of the Benz SPH code.

The Joint Milliarcsecond Astrometry Pathfinder Survey (JMAPS) is a small, space-based, all sky, visible wavelength, astrometric and photometric survey mission for 0th through 14th I-band magnitude stars with a planned 2013 launch. The primary objective of the JMAPS mission is the generation of an astrometric star catalog with 1 milliarcsecond (mas) positional accuracy or better and photometry to the 1% accuracy level or better at 1st to 12th mag. A 1-mas all–sky survey will have a significant impact on our current understanding of galactic and stellar astrophysics. JMAPS will improve our understanding of the origins of nearby young stars, provide insight into the dynamics of star formation regions and associations, investigate the dynamics and membership of nearby open clusters.

We present a detailed study of the physical properties of the nebular material in multiple knots of the blue compact dwarf galaxy Haro 15. Using long slit and echelle spectroscopy, obtained at Las Campanas Observatory, we study the physical conditions (electron density and temperature), ionic and total chemical abundances of several atoms, reddening and ionization structure. The latter was derived by comparing the oxygen and sulphur ionic ratios to their corresponding observed emission line ratios (the η and η' plots) in different regions of the galaxy. Applying direct and empirical methods for abundance determination, we perform a comparative analysis between these regions.

After a brief review of past N-body models of the Milky Way, I consider some of the difficulties that are inherent in the N-body approach to modelling any disk galaxy.

Globular cluster (GC) systems are powerful probes to study the evolutionary histories of galaxies, being tracers of major star fomation episodes (Brodie & Strader 2006). They are found around all major galaxies and are easy to see far beyond the local group. Age dating GCs therefore helps pinpoint epochs of major star forming events. Spectroscopic age dating though (Strader et al. 2005) is extremely time consuming and can only access the few brightest clusters. An alternative is to combine near-infrared (NIR) and optical photometry, and therefore have a better chance in lifting the age metallicity degeneracy than with optical colours alone. This approach relies in testing GC colours against simple stellar population (SSP) models. The first studies following this technique showed the possible existence of a high percentage of intermediate age (2-3 Gyrs) GCs in early-type galaxies known to contain old stellar populations from integrated light studies. Two strong cases can be listed: NGC 4365 (Puzia et al. 2002, Larsen et al. 2005) and NGC 5846 (Hempel et al. 2003). In the present study we combine NIR deep photometry obtained with the WHT/LIRIS instrument and archival HST/ACS optical images to determine g(F475W), z(F840LP) and K(2.2m) magnitudes and colours of GCs in 14 early-type galaxies.

We investigated the use of support vector machines (SVMs) to distinguish quasars from stars using survey databases from different wavebands. We first employed a random forest approach for selection and weighting of features. We find that SVMs are an effective method to preselect quasar candidates from multiwavelength data.

We performed a 1D LTE chemical abundance analysis of an extremely metal-poor star BD+44°493 ([Fe/H]= −3.7), and set a very low upper limit for its Be abundance: A(Be) < −2.0. It may indicate that the decreasing trend of Be abundances with lower [Fe/H] still holds at [Fe/H] < −3.5, and demonstrate that high C and O abundances do not necessarily imply high Be abundances. However, since the star is a subgiant with Teff ~ 5500K, Be may be depleted.