The rates of SNe Ia for double-degenerate and single-degenerate scenarios are computed for the models of spiral and elliptical galaxies. The number of nuclear burning white dwarfs (NBWDs) is traced. The data favors the double-degenerate scenario and suggests a lower number of NBWDs per unit mass in ellipticals. Their lower average mass is one of the reasons for the difference in the number of supersoft X-ray sources observed in the galaxies of different types.

V405 And is an ultrafast-rotating (Prot ≈ 0.46 days) eclipsing binary. The system consists of a primary star with radiative core and convective envelope, and a fully convective secondary. Theories have shown that stellar structure can depend on magnetic activity, i.e., magnetically active M-dwarfs should have larger radii. Earlier light curve modelling of V405 And indeed showed this behaviour: we found that the radius of the primary is significantly larger than the theoretically predicted value for inactive main sequence stars (the discrepancy is the largest of all known objects), while the secondary fits well to the mass-radius relation. By modelling our recently obtained light curves, which show significant changes of the spotted surface of the primary, we can find further proof for this phenomenon.

GALEX (the Galaxy Evolution Explorer) has provided far-UV(1344-1786Å) and near-UV(1771-2831Å) imaging of several Planetary Nebulae (e.g., Bianchi et al. 2008, Bianchi 2012), with flux limits ~27.5 mag/sq.arcsec for objects in the Medium-deph Imaging Survey (MIS). PNe images in the GALEX broad-band UV filters include flux from both nebular line and continuum emission. We use the GALEX grism observing mode to obtain slitless spectral imaging of a sample of PNe with diameters >1′, in the near-UV. We show the first data from this program. The grism produces 2D images of the prominent UV nebular emission lines, when such lines dominate the flux. Combined with monochromatic images of diagnostic lines in the optical domain, such data help detect and interpret ionization and shock fronts, especially in faint nebular regions.

The ISO and Spitzer space observatories yielded a treasure trove of data on dust and ices covering dust grains. Now Herschel, and soon SOFIA and ALMA, will provide unprecedented views of the molecular world of the interstellar medium (ISM). It is on dust grains that key ISM molecules, such as hydrogen, formaldehyde, methanol, and water are formed. As a result of these new observations, there is a great need to know more about the interaction processes of atoms and molecules with dust grains. (The Proceedings of the 2010 NASA Laboratory Astrophysics Workshop (http://www-cfadc.phy.ornl.gov/nasa_law/) give a good view of recent accomplishments in the study of atom/molecule - solid interactions as well as other aspects of laboratory astrophysics.)

The past year has seen major advances in the observational status of Stellar Tidal Disruption, with the discovery of two strong optical candidates in archived SDSS data and the real-time X-ray detection of Swift J1644+57, plus rapid radio and optical follow-up establishing it as a probable Tidal Disruption Flare (TDF) in “blazar mode”. These observations motivated a workshop devoted to discussion of such events and of the theory of their emission and flare rate. Observational contributions included a presentation of Swift J2058+05 (a possible second example of a TDF in blazar mode), reports on the late-time evolution and X-ray variability of the two Swift events, and a proposal that additional candidates may be evidenced by spectral signatures in SDSS. Theory presentations included models of radio emission, theory of light curves and the proposal that GRB101225A may be the Galactic tidal disruption of a neutron star, an interpretation of Swift J1644+57 as due to the disruption of a white dwarf instead of main-sequence star, calculation of the dependence of the TDF rate on the spin of the black hole, and analysis of the SDSS events, fitting their SEDs to profiles of thoretical emission from accretion disks and showing that their luminosity and rate are consistent with the proposal that TDEs can be responsible for UHECR acceleration.

We report results for two epochs of spectropolarimetry on the luminous type IIn SN2010jl, taken at ≈36 and 85 days post-explosion with VLT FORS2-PMOS. The high signal-to-noise data demonstrate distinct evolution in the continuum and the broad lines point to a complex origin for the various emission components and to a potentially common polarization signal for the type IIn class even over 1-2 orders of magnitude in luminosity output.

Global suface temperature has showed a rise trend in the last 150 years. This has been mainly attributed to the anthropogenic induced grenhouse gases emissions. However, the role of natural processes is not completely understood and should not be underestimated. In this work, we compare the long term variability of solar activity (as quantified by the sunspot number) with several surface temperature series from different geographical regions (global, hemispheric and latitudinal ranges). The interval of analysis is 1880-2005. The data are analyzed with wavelet multiresolution technique. It has been found that the solar activity long term trend has a maximum around 1970, while air surface temperature series showed maximum (still rising) at 2005. There are differences in the long term trend for Northern and Southern hemispheres. These differences and the relation with solar activity are discussed in this work.

In our Spitzer 24 μm survey of hot white dwarfs (WDs) we found 9 WDs with IR excesses, 7 of them are still central stars of planetary nebulae (CSPNs). We have thus carried out a Spitzer archival survey of CSPNs, and found additional objects with IR excesses. To date, a total of 13 CSPNs show IR excesses from Spitzer observations. These mid-IR excesses are indicative of the presence of circumstellar dust, which could be produced by collisions or disruption of sub-planetary objects. To further assess the nature of these IR excesses, we have obtained Spitzer IRS, Gemini NIRI and Michelle, and KPNO 4m echelle spectra of these objects. In this poster, we summarize the spectroscopic observations and discuss the nature of these IR excesses.

Commission 41 was created at the VIIth IAU General Assembly in Zürich in 1948. From an inauspicious start—Otto Neugebauer was appointed the first President in his absence, but proceeded to express his conviction that “an international organization in the history of astronomy has no positive function. . .my only activity during my term of service consisted in iterated attempts to resign”—the Commission quickly assumed a key role in the international development of the history of astronomy as an academic discipline.

In the past five years systematic searches, serendipitous discoveries and archival searches have yielded over a dozen transients that are brighter than novæ but fainter than supernovæ. The observed properties of these “gap” transients tend to place them in distinct classes, some being about 100 times brighter than novæ and durations of nearly 100 days (e.g., M85 OT, PTF10fqs), while others (such as SN2002bj and PTF10bhp) nearly reach supernovæ luminosities but fade in five days. The state of theoretical understanding varies substantially across the class of objects, and is ripe for progress.

The spectral energy distribution (SED) gives a complete picture of the radiation of space objects and may result in correct classifications compared to those based only on optical (or other local) spectra. This is especially crucial for active galaxies, both AGN and Starbursts (SB). For this, multiwavelength (MW) data are needed taken from available surveys and catalogs. We have cross-correlated the Catalogue of quasars and active galaxies with all-sky or large-area MW catalogues, such as X-ray ROSAT (BSC and FSC), UV GALEX (MIS and AIS), optical APM, MAPS, USNO-B1.0, GSC 2.3.2, and SDSS DR8, NIR 2MASS, MIR/FIR WISE, IRAS (PSC and FSC) and AKARI (IRC and FIS), radio GB6, NVSS, FIRST, and WENSS. We have established accurate positions and photometry for a few thousands of objects that appeared in the catalog with poor data, as well as achieved the best astrometric and photometric data for all objects. This allowed correct cross-correlations and establishing correct MW data for these objects. As a result, we obtained 34 photometric points from X-rays to radio and using VO tools built SEDs for some 10,000 bright objects. Some data from other surveys were also used, such as Chandra, XMM, Spitzer, etc. All objects were grouped into several forms of SED and were compared to the known optical classes given in the catalog (QSO, BLL, Sy1, Sy1.2–1.9, Sy2, LINER, SB, and HII). This allowed reveal obscured AGN, as well as find previously misclassified objects. A homogeneous classification for these objects was established. The first part of this project is presented; establishment of accurate positions and photometry and cross-correlations with MW catalogs.

The 2D and 3D Doppler tomograms of X-ray binary system Cyg X-1 (V1357 Cyg) were reconstructed from spectral data for the line HeII 4686Å obtained with 2-m telescope of the Peak Terskol Observatory (Russia) and 2.1-m telescope of the Mexican National Observatory in June, 2007. Information about gas motions outside the orbital plane, using all of the three velocity components Vx, Vy, Vz, was obtained for the first time. The tomographic reconstruction was carried out for the system inclination angle of 45°. The equal resolution (50 × 50 × 50 km/s) is realized in this case, in the orbital plane (Vx, Vy) and also in the perpendicular direction Vz. The checkout tomograms were realized also for the inclination angle of 40° because of the angle uncertainty. Two versions of the result showed no qualitative discrepancy. Details of the structures revealed by the 3D Doppler tomogram were analyzed.

We performed Rapid-Response Mode (RRM) VLT/UVES high-resolution UV/ optical spectroscopy of the GRB 080310 afterglow, starting 13 min after the burst trigger, in order to investigate the ISM in the GRB host galaxy. The four spectra show remarkable features at zGRB, including a low log N(H i) = 18.7 and time-variable absorption from ground-state and excited levels of Fe ii and Fe iii, the latter being observed for the first time in a GRB afterglow. These observations indicate i) ongoing photo-ionization of the surrounding gas due to the GRB radiation and ii) Fe and Cr overabundances in the host galaxy ISM. We derive ionic column densities through a four-component Voigt-profile fit of the absorption lines and investigate the pre-burst ionization level of the gas with CLOUDY photo-ionization modelling. The resulting intrinsic [Si/Fe] = −1.4 ([C/H] = −1.3, [O/H] < −0.8, [Si/H] = −1.2, [Cr/H] = +0.7 and [Fe/H] = +0.2) for the whole line profile - and even more extreme for one of the absorption components - cannot be explained with current models of SN yields. Dust destruction may contribute to the marked iron overabundance, possibly induced by the burst. The overall high iron enhancement along the line-of-sight also suggests little recent star formation in the host galaxy.

Solar variability and its effects on the physical variability of our (space) environment produces complex signals. In the indicators of solar activity at least four independent cyclic components can be identified, all of them with temporal variations in their timescales.

Time-frequency distributions (see Kolláth & Oláh 2009) are perfect tools to disclose the “music scores” in these complex time series. Special features in the time-frequency distributions, like frequency splitting, or modulations on different timescales provide clues, which can reveal similar trends among different indices like sunspot numbers, interplanetary magnetic field strength in the Earth's neighborhood and climate data.

On the pseudo-Wigner Distribution (PWD) the frequency splitting of all the three main components (the Gleissberg and Schwabe cycles, and an ≈5.5 year signal originating from cycle asymmetry, i.e. the Waldmeier effect) can be identified as a “bubble” shaped structure after 1950. The same frequency splitting feature can also be found in the heliospheric magnetic field data and the microwave radio flux.

There is a general agreement that Type Ia supernovae correspond to the thermonuclear runaway of a white dwarf (WD) in a compact binary. The details of these progenitor systems are still unclear. Using the population synthesis code SeBa and several assumption for the WD retention efficiency, we estimate the delay times and supernova rates for the single degenerate scenario.

The Galaxy is composed of four distinct structures, i.e., halo, bulge, and thick and thin disks, that are formed and evolved on different timescales; thus accordingly the speeds of chemical enrichment are different from one another, which is imprinted in individual stellar abundances. To decipher them, precise knowledge of the timing of the release of nucleosynthesis materials from various production sites is critical. The delay time distribution (DTD) of Type Ia supernovae (SNe Ia), recently revealed by the SNe Ia surveys of external galaxies, is incorporated into the models of chemical evolution for each structure. Here we report that the observed chemical properties for the thin and thick disks are compatible with a new SNe Ia DTD, and suggests a close chemical connection between the two in the way that the thin disk is formed from gas left after thick disk formation. This nicely explains the lack of thin disk stars with [Fe/H] ≲ −0.8. In this new context, a top-heavy IMF for the bulge is firmly confirmed. Finally we discuss the possibility of some modification of the DTD that might be considered for the halo case.

The Galactic Ridge X-ray Emission (GRXE) spectrum has strong iron emission lines at 6.4, 6.7, and 7.0 keV, each corresponding to the neutral (or low-ionized), He-like, and H-like iron ions. The 6.4 keV fluorescence line is due to irradiation of neutral (or low ionized) material (iron) by hard X-ray sources, indicating uniform presence of the cold matter in the Galactic plane. In order to resolve origin of the cold fluorescent matter, we examined the contribution of the 6.4 keV line emission from white dwarf surfaces in the hard X-ray emitting symbiotic stars (hSSs) and magnetic cataclysmic variables (mCVs) to the GRXE. In our spectral analysis of 4 hSSs and 19 mCVs observed with Suzaku, we were able to resolve the three iron emission lines. We found that the equivalent-widths (EWs) of the 6.4 keV lines of hSSs are systematically higher than those of mCVs, such that the average EWs of hSSs and mCVs are 180−10+50 eV and 93−3+20 eV, respectively. The EW of hSSs compares favorably with the typical EWs of the 6.4 keV line in the GRXE of 90–300 eV depending on Galactic positions. Average 6.4 keV line luminosities of the hSSs and mCVs are 9.2 × 1039 and 1.6 × 1039 photons s−1, respectively, indicating that hSSs are intrinsically more efficient 6.4 keV line emitters than mCVs. We estimated required space densities of hSSs and mCVs to account for all the GRXE 6.4 keV line emission flux to be 2 × 10−7 pc−3 and 1 × 10−6 pc−3, respectively. We also estimated the actual 6.4 keV line contribution from the hSSs, which is as much as 30% of the observed GRXE flux, and that from the mCV is about 50%. We therefore conclude that the GRXE 6.4 keV line flux is primarily explained by hSSs and mCVs.

In the triennium 2006–2009, the WG Archives promoted an action of recognition of the archival documents concerning the foundation of IAU. The pretext was given by the fact that the year 2009 was the 90th anniversary of the establishment of IAU and the WG considered worth to start checking the conditions of preservation and conservation of such documents, in view of the approaching centenary.

Never before has there been such a wealth of versatile ground- and space-based facilities with which to detect variable emission across the electromagnetic spectrum and beyond, to non-EM signals such as neutrinos and gravitational waves, to probe the most extreme phenomena in the Universe. The variable sky is already providing a wealth of new and surprising observations of phenomena such as GRBs, SNe and AGN that are pushing current theories beyond the state of the art. Multi-messenger follow-up will soon become de rigeur, and upcoming radio and optical all-sky transient surveys will revolutionise the study of the transient Universe. In addition to the technical and data challenges presented by such surveys, a major new challenge will be the interpretation of the wealth of available data and the identification of the underlying physics of new classes of variable (and potentially exotic) objects. Theoretical predictions will be vital for interpreting these future transient discoveries.

The goal of this workshop was to bring together theorists and observers in order to identify unexplored synergies across three main research areas of extreme physics: gamma-ray bursts, supernovæ and, more generically, relativistic jets. It aimed to discuss key outstanding questions in these rapidly moving fields, such as the composition and acceleration of GRB and AGN jets, GRB progenitors and central engines, the origin of the wide range of observed variability time-scales in GRB prompt and after-glow light curves and related cosmological applications, the physics of the newly-discovered ultra-luminous SN-like optical transients—as well as to speculate on what we might hope to discover with future technology.

The workshop absorbed two 90-minute sessions, selecting 3 main science topics (Relativistic Jets, GRBs and SNe) which it organised as structured discussions driven by a series of short but provocative questions. The final session featured a panel-led debate but with full audience participation.

We propose to measure the radii of the Penn State - Toruń Planet Search (PTPS) exoplanet host star candidates using the CHARA Array. Stellar radii estimated from spectroscopic analysis are usually inaccurate due to indirect nature of the method and strong evolutionary model dependency. Also, the so-called degeneracy of stellar evolutionary tracks due to convergence of many tracks in the giant branch decreases the precision of such estimates. However, the radius of a star is a critical parameter for the calculation of stellar luminosity and mass, which are often not well known especially for giants. With well determined effective temperature (from spectroscopy) and radius, the luminosity may be calculated precisely. In turn also stellar mass may be estimated much more precisely. Therefore, direct radii measurements increase precision in the determination of planetary candidates masses and the surface temperatures of the planets.