相关论文: Circumstellar environment of RX Puppis

EX Lup is a well-studied T Tauri star that represents the prototype of young eruptive stars EXors. In this paper we analyze new adaptive optics imaging and spectroscopic observations of EX Lup and its circumstellar environment in…

Observations of protoplanetary disks (PPDs) at sub-mm wavelengths suggest that polarisation is caused by scattering of thermal radiation. Most of the dust models that are used to explain these observations have major drawbacks: They either…

We study the orbital evolution of wide binary stars in the solar neighborhood due to gravitational perturbations from passing stars. We include the effects of the Galactic tidal field and continue to follow the stars after they become…

In the present study we aim to investigate the circumstellar environment of the spectroscopic binary T Tauri star CS Cha. From unresolved mid- to far-infrared photometry it is predicted that CS Cha hosts a disk with a large cavity. In…

We present two-dimensional (2D) radiative transfer modeling of IRC+10216 at selected moments of its evolution in 1995-2001, which correspond to three epochs of our series of 8 near-infrared speckle images (Osterbart et al. 2000, Weigelt et…

Some accretion powered X-ray pulsars with supergiant companion stars undergo occasional rapid spin-up episodes that last for weeks to a few months. We explore the changes in the accretion environment of the pulsar GX 301-2 during its latest…

Massive stars in the red supergiant (RSG) phase are known to undergo strong mass loss through winds and observations indicate that a substantial part of this mass loss could be driven by localised and episodic outflows. Various mechanisms…

Detailed models are presented for the late epoch mid infrared (MIR) emission from collisionally heated grains in the shocked circumstellar gas around SN 1987A. Thermal dust emission from a region of moderate density interior to the thick…

We present period-luminosity diagrams for nearby Miras and semiregulars, selecting stars with parallaxes better than 20 per cent and well-determined periods. Using K-band magnitudes, we find two well-defined P-L sequences, one corresponding…

Interstellar dust grains are often aligned. If the grain alignment direction varies along the line of sight, the thermal emission becomes circularly-polarized. In the diffuse interstellar medium, the circular polarization at far-infrared…

We report the first spatially resolved radio continuum measurements of the Mira AB symbiotic binary system, based on observations obtained with the Very Large Array (VLA). This is the first time that a symbiotic binary has been resolved…

We present X-ray observations of the field containing Nova Puppis 1942 (CP Pup) and Nova Puppis 1991 (V351 Pup), done with ASCA in 1998, and with XMM-Newton in 2005. The X-ray and UV luminosity of CP Pup seem to have remained approximately…

The dynamical interactions between young binaries can perturb the material distribution of their circumstellar disks, and modify the planet formation process. In order to constrain the impact and nature of the binary interaction in the RW…

Consistent stellar evolution and nonlinear radial stellar pulsation calculations were carried out for models of asymptotic giant branch stars with initial masses $1.5M_\odot\le M_\mathrm{ZAMS}\le 3M_\odot$ and initial metal abundance…

We have obtained 11.7 and 17.9 micron images at the Keck I telescope of the circumstellar dust emission from L2 Pup, one of the nearest (D = 61 pc) mass-losing, pulsating, red giants that has a substantial infrared excess. We propose that…

Red supergiants (RSGs) are an evolved stage in the life of intermediate massive stars (<25Mo). For many years their location in the H-R diagram was at variance with the evolutionary models. Using the MARCS stellar atmosphere models, we have…

Magnitude-limited samples of spiral galaxies drawn from the Ursa Major and Pisces clusters are used to determine their extinction properties as a function of inclination. Imaging photometry is available for 87 spirals in B,R,I and K' bands.…

We report on the discovery of variable circular polarization from the remnant of Nova Chamaeleontis 1953 (RR Cha). The circular polarization appears to be modulated on the primary's spin period and harmonics of the positive superhump…

We extend and investigate the spheroidal model of interstellar dust grains used to simultaneously interpret the observed interstellar extinction and polarization curves. We compare our model with similar models recently suggested by other…

We study the extinction properties of the composite dust grains, consisting of host silicate spheroids and graphite as inclusions, using discrete dipole approximation (DDA). We calculate the extinction cross sections of the composite grains…