We report new calculations of the effective recombination coefficients for the nebular N ii and O ii lines and very deep spectroscopy of the bright planetary nebula (PN) NGC 7009.

Dynamics of magnetic field decay is numerically studied. For neutron stars with strong magnetic fields, the Hall drift timescale in their crust is very short, and therefore the evolution is significantly affected. The nonlinear coupling between poloidal and toroidal components of the magnetic field is studied. It is also found that the polar field at the surface is highly distorted during the Hall drift timescale. For example, polar dipole field-strength temporarily decreases not by dissipation but by advection. This fact suggests that the dipole field-strength is not sufficient to determine the border between pulsars and magnetars.

We have compiled and analyzed historical meter and meteor shower records in Korean, Chinese, and Japanese chronicles. We have confirmed the peaks of Perseids and an excess due to the mixture of Orionids, north-Taurids, or Leonids through the Monte-Carlo test from the Korean records. The peaks persist for almost one thousand years. We have also analyzed seasonal variation of sporadic meteors from Korean records. Major features in Chinese meteor shower records are quite consistent with those of Korean records, particularly for the last millennium. Japanese records also show Perseids feature and Orionids/north-Taurids/Leonids feature, although they are less prominent compared to those of Korean or Chinese records.

Present day massive (Mstellar > 1011 M⊙) galaxies are composed mostly of early-type objects. To ascertain whether this was also the case at higher redshift, we have compiled over a thousand massive galaxies at 0 < z < 3 with HST imaging and spectroscopic redshifts for the majority of them. We have also analyzed using 3D spectroscopy another sample of 10 massive galaxies at z = 1.4. Both works highlight the progressive change between a late-type/peculiar nature at z > 2 and a predominance of early-type morphologies only since z = 1.

We study and compare the stellar populations of host galaxies of different types of supernovae (SNe): SN Ia and core collapse SN (SN II and SN Ibc) at the same time. The 234 sample galaxies are selected by cross-matching the Asiago Supernova Catalogue (ASC) and the SDSS-DR7 main galaxy sample (MGS). The STARLIGHT software is used to analyze their stellar populations by fitting the continua and absorption lines of the hosts.

Observations of the interplanetary shock provide us with strong evidences of particle acceleration to multi-MeV protons in a coronal mass ejection (CME). Diffusive shock acceleration (DSA) is an efficient mechanism for cosmic ray (CR). This work presents a dynamical Monte Carlo simulation of a CME-driven shock on 14-Dec-2006 by using a series of Gaussian scattering angular distributions. With the simulated results, we find that particle energy spectrum is affected by energy injection processes under the anisotropic scattering law.

Classical Cepheids in Galactic open clusters (cluster Cepheids: CCs) have been studied extensively for multiple decades, thanks to their importance as calibrators of the Galactic Cepheid period–luminosity relation (PLR). Here we revisit the calibration of the Galactic PLR using a new sample of CCs, since even recent calibrations show significant discrepancies. The CC sample employed for the calibration is based on the preliminary results of a self-consistent, eight-dimensional all-sky census. This census is based mostly on literature data, supplemented with high-precision radial-velocity observations from both hemispheres. New CCs are identified from our census and the degree of confidence in membership is quantified for known candidates. Using only bona fide CCs, we obtain MV = (−3.08 ± 0.50) log P + (−0.94 ± 0.42) mag, which is in perfect agreement with the results by Sandage, Tammann, and Reindl, albeit with larger error bars and an rms of 0.21 mag. The key to obtaining a meaningful calibration is to employ accurate cluster distance moduli and space reddening values. A homogeneous study of all bona fide host clusters would be desirable to increase precision and confidence in the calibration.

The University of Zululand, situated along the east coast of KwaZulu-Natal, has a thriving Science Centre (USC) situated in the developing port city of Richards Bay. Over 30 000 learners visit the centre annually, and it consists of an exhibition area, an auditorium, lecture areas and offices. The shows consist of interactive games, science shows, competitions, quizzes and matriculation workshops. Outreach activities take place through a mobile science centre for schools and communities that cannot visit the centre.

Though multiwavelength astronomy was born over fifty years ago, the wide-spread use of multiwavelength diagnostics is a more recent phenomenon. Even in the last decade, astronomers continued to rely on the optical domain for the bulk of their analysis. However, this is certain to change, as most of the current and future instruments are increasingly dedicated to observations in the infrared, from the near- to the far-infrared bands.

Navegar Foundation has dedicated the past twelve years to astronomy public outreach by engaging the community in activities provided by the planetarium and observatory. The activities developed range from exhibitions to telescope observing sessions and planetarium shows. Whether partnering with local entities or with a variety of joint national and international activities, Navegar always had a proactive policy on raising awareness of light pollution issues. The outcomes of these activities are discussed.

In this article we show that massive and hot fragments forming in protostellar disks can leave characteristic signatures in spectral energy distributions (SEDs) of young stellar objects. This occurs when the fragment evaporates dust in its atmosphere, which results in a sharp drop in opacity and subsequent rise in the surface temperature of the fragment. These hot fragments can produce local maxima in the SEDs at 5–10 μm.

We describe how observations of pulsars from the Parkes Pulsar Timing Array (PPTA) project have been used to develop a pulsar-based timescale. This is the first such timescale that has a precision comparable to uncertainties in international atomic timescales.

The unmatched X-ray resolution of Chandra allows probing the gas flow near quiescent supermassive black holes (BHs). The radius of BH gravitational influence on gas, called the Bondi radius, is resolved in Sgr A* and NGC 3115. Shallow accretion flow density profiles n ∝ r−β with β=0.7–1.0 were found for Sgr A* and NGC 3115 with the help of Chandra. We construct self-consistent models with gas feeding and dynamics from near the Bondi radius to the event horizon to explain the observations. Gas is mainly supplied to the region by hot colliding stellar winds. Small-scale feedback such as conduction effectively flattens the density profile from steep β=1.5 in a Bondi flow. We further constrain density and temperature profiles using the observed radio/sub-mm radiation emitted near the event horizon. We discuss the present state of our numerical model and its qualitative features, such as the role of the galactic gravitational potential and the random motion of wind-emitting stars.

We study the host galaxy properties of radio sources in the AKARI-North Ecliptic Pole (NEP) field, using an ensemble of multi-wavelength datasets. We identify both radio-loud and radio-quiet AGN and study their host galaxy properties by means of SED fitting. We investigate the relative importance of nuclear and star-formation activity in radio-AGN and assess the role of radio-AGN as efficient quenchers of star-formation in their host galaxies.

Most early-type galaxies are not devoid of cold and warm gas. The origin and ionization of this gas reveal the intriguing ongoing evolution of these galaxies. In most cases, the warm ionized gas shows emission-line spectra similar to low-ionization nuclear emission-line regions (LINERs). Their ionization mechanism has been hotly debated. We will present evidence from line ratio gradient that rules out AGN and shocks as the dominant ionization mechanism, and suggests the ionizing sources follow the stellar density profile. Hot evolved stars are the favorite candidates but bring new puzzles.

This finding allows us to obtain a gas-phase metallicity calibration in these early-type galaxies, using the line emission. We will show how the metallicity of the warm gas depends on stellar mass and stellar age, and what it tells us about the origin of the warm gas in these galaxies.

Radiation of supersoft X-ray sources (SSS) dominates both the supersof X-ray and the far-UV domain, and can be detected also within the optical/near-IR wavelengths. To determine fundamental parameters of SSSs, a multiwavelength approach in modeling their spectra is essential. By this way, the basic physical parameters of a SSS (the temperature, radius, luminosity and column density of the neutral hydrogen) can be determined unambiguously. Here I demonstrate this case for the symbiotic X-ray binary RXJ0059.1-7505 (LIN 358) in the Small Magellanic Cloud (SMC).

Non gaussian sources of erros need to be taken into consideration when searching for planetary transits. Such phenomena are mostly caused by the impact of high energetic particles on the detector (Pinheiro da Silva et al. 2008). The detection efficiency of transits, therefor, depend significantly on the data quality and the algorithms utilized to deal with these errors sources. In this work we show that a modified detrend algorithm CDA (CoRoT Detrend Algorithm; Mislis et al. 2010) using a robust statistics and an empirical fit, instead of a polynomial one, can eliminate more efficiently gaps in the data and other long-term trends from the light-curve. Using this algorithm enables us to obtain a reconstructed light-curve with better signal-to-noise ratio that allows to improve the detection of exoplanet transits, although long term signals are destroyed. The results show that these modifications lead to an improved BLS (Box-fitting Least Squares; Kovács, Zucker & Mazeh 2002) algorithm spectrum. At the end we have compared our planetary search results with CoRoT (Convection, Rotation and planetary Transits) satellite chromatic light-curves available in the literature.

In this paper, we focus to study the frequency and time properties of a group of spikes recorded by the 1.08-2.04 GHz spectrometer of NAOC on 27 October 2003. At the first we calculate the mean and minimum bandwidth of the spikes. We apply two different methods based on the wavelet analysis according to Messmer & Benz (2000). The first method determines the dominant spike bandwidth scale based on their scalegram, and the second method is a feature detection algorithm in the time-frequency plane. Secondly the time profile of each single spike was fitted and analyzed. In particular, we determined the e-folding rise and decay times corresponding to the ascending and decaying parts of the time profile, respectively. Several important correlations were studied and compared with the results in earlier literature, i.e. those between duration and frequency, e-folding rise time and decay time, e-folding decay time and duration, and e-folding decay time and peak flux. Finally some parameters of source region were estimated and the possible decaying mechanism was discussed.

We summarise the motivations and main results of the joint discussion “3D Views of the Cycling Sun in Stellar Context”, and give credit to contributed talks and poster presentations, as due to the limited number of pages, this proceedings could only include contributions from the keynote speakers.

We present evidence for chaotic dynamics in pulsar spin-down rates originally measured by Lyne et al. (2010). Using techniques that allow us to re-sample the original measurements without losing structural information, we have searched for evidence for a strange attractor in the time series of frequency derivative for each pulsar. Our measurements of correlation dimension and Lyapunov exponent show, particularly in the case of PSR B1828-11, that the underlying behavior appears to be driven by a strange attractor with approximately three governing nonlinear equations.