Related papers: Circumstellar environment of RX Puppis
We present recent polarimetric images of the highly variable star R CrB using ExPo and archival WFPC2 images from the HST. We observed R CrB during its current dramatic minimum where it decreased more than 9 mag due to the formation of an…
We investigate the luminosity and redshift dependence of the quasar continuum by means of composite spectrum using a large non-BAL radio-quiet quasar sample drawn from the Sloan Digital Sky Survey. Quasar continuum slopes in the UV-Opt band…
We present high-resolution infrared (2--18 micron) images of the archetypal periodic dust-making Wolf-Rayet binary system WR140 (HD 193793) taken between 2001 and 2005, and multi-colour (J -- [19.5]) photometry observed between 1989 and…
Evolution of stars with initial masses $M_\mathrm{ZAMS}=1.1M_\odot$, $1.3M_\odot$, $1.5M_\odot$ and relative mass abundances of metals $Z=0.006$ and 0.02 was computed from the main sequence up to the final AGB stage. Selected models of…
We revisit the nature of large dips in flux from extinction by dusty circumstellar material that is observed by Kepler for many young stars in the Upper Sco and $\rho$ Oph star formation regions. These young, low-mass "dipper" stars are…
We study the morpho-kinematics of the circumbinary envelope of Mira Ceti between $\sim$100 and $\sim$350 au from the stars using ALMA observations of the SiO ($\nu$=0, $J$=5-4) and CO ($\nu$=0, $J$=3-2) emissions with the aim of presenting…
Scattered light images of the optically thin dust disk around the 5 Myr old star HD141569 have revealed its complex asymmetric structure. We show in this paper that the surface density inferred from the observations presents similarities…
Theoretical analysis and observational evidences indicate that a brown dwarf with effective temperature greater than 1400 K would have dust cloud in its atmosphere. In this letter, we show that dust scattering should yield polarized…
We present the discovery that Mira variables separate in two distinct sequences in a near- to mid-IR color versus pulsation period diagram, if a distinction is made with respect to the presence of technetium (Tc) in the stars. Tc is an…
Observed ultraviolet (UV) colours of nearby disc galaxies show a reddening relative to their expected intrinsic colours. Since the 2175 \AA bump found in the Milky Way's dust extinction law blues the UV colours, it might suggest that dust…
We discuss the central role that dust condensation plays in shaping the observational appearance of outflows from coalescing binary systems. As binaries begin to coalesce, they shock-heat and expel material into their surroundings.…
The Milky Way's central parsec is a highly extinguished region with a population of high-proper-motion stars. We have tracked 145 stars for $\sim$10 years at wavelengths between 1 and 4 microns to analyze extinction effects in…
We investigate four young, but non-accreting, very low mass stars in Orion, which show irregular eclipses by circumstellar dust. The eclipses are not recurring periodically, are variable in depth, lack a flat bottom, and their duration is…
The dust extinction curve is typically parameterized by a single variable, R(V), in optical and near-infrared wavelengths. R(V) controls the slope of the extinction-vs.-wavelength curve, and is thought to reflect the grain-size distribution…
Variations in polarization efficiency (p/A) of interstellar grains as a function of environment place vital constraints on models for the mechanism of their alignment. We use polarimetry of background field stars to investigate alignment in…
Far-infrared Spitzer observations of elliptical galaxies are inconsistent with simple steady state models of dust creation in red giant stars and destruction by grain sputtering in the hot interstellar gas at T ~ 10^7 K. The flux at 24…
JHK spectroscopic and photometric observations are reported for the enigmatic, nova-like, variable V445 Puppis which erupted at the end of 2000. The near-IR spectra are hydrogen-deficient and unusually rich in CI lines. The important CI…
Red supergiants (RSGs) are an evolved stage in the life of intermediate massive stars (than than 25 solar masses). For many years, their location in the H-R diagram was at variance with the evolutionary models. Using the MARCS stellar…
We present the first wide-field H-alpha imaging survey around the distant cluster RXJ1716.4+6708 at z=0.81 with a narrow-band filter on MOIRCS/Subaru, down to SFR(Ha)~1Msun/yr. Combining with a wide-field MIR imaging survey with AKARI, we…
The correlation between optical starlight polarization and polarized thermal dust emission can be used to infer intrinsic dust properties. This correlation is quantified by the ratio Rp/p, which has been measured to be 5.42 +/- 0.05 MJy…