Related papers: Evidence for variable outflows in the Young Stella…
We present observations of rapid (sub-second) optical flux variability in V404 Cyg during its 2015 June outburst. Simultaneous three-band observations with the ULTRACAM fast imager on four nights show steep power spectra dominated by slow…
We have performed an unbiased deep near-infrared survey toward the Aquila molecular cloud with a sky coverage of ~1 deg2. We identified 45 molecular hydrogen emission-line objects(MHOs), of which only 11 were previously known. Using the…
The Infrared Space Observatory (ISO) was an extremely successful european space mission that gave us an unparallel view of the Universe in the infrared, and provided us with hundreds of observations of star forming regions and bipolar…
V1765 Cyg is a detached eclipsing binary containing a B0.5 supergiant and a B1 main-sequence star, with an orbital period of 13.37 d and an eccentricity of 0.315. The system shows apsidal motion and the supergiant exhibits strong stochastic…
Observational signatures of accretion disc winds have been found in a significant number of low-mass X-ray binaries at either X-ray or optical wavelengths. The 2015 outburst of the black hole transient V404 Cygni provided a unique…
Far infrared fine structure line data from the ISO archive have been extracted for several hundred YSOs and their outflows, including molecular (CO) outflows, optical jets and Herbig-Haro (HH) objects. Given the importance of these lines to…
We have observed V751 Cyg with the ROSAT HRI during its recent optical low state and clearly detect it at a count rate of 0.015 cts/s. The X-ray intensity is a factor of ~20 higher than the upper limit obtained with the ROSAT PSPC during…
Optical and near-infrared variability is a well-known property of young stellar objects. However, a growing number of recent studies claim that a considerable fraction of them also exhibit mid-infrared flux changes. With the aim of studying…
We present an analysis of low- and medium resolution spectra of the very fast nova, Nova Cygni 2001/2 (V2275 Cyg) obtained at nine epochs in August, September and October, 2001. The expansion velocity from hydrogen Balmer lines is found to…
We aim to characterize the distribution and composition of circumstellar material around young massive stars, and to investigate exactly which physical structures in these objects are probed by long-baseline mid-infrared interferometric…
We report on the preliminary results of a three-year monitoring campaign of Galactic and Magellanic LBVs with both moderate and high resolution spectroscopy. We have collected more than 500 moderate-resolution spectra of 20 stars in the red…
We present a parsec-scale molecular hydrogen (H$_2$ 1-0 S(1) at 2.12~\micron) outflow discovered from the UKIRT Widefield Infrared Survey for H$_2$. The outflow is located in the infrared dark cloud core MSXDC G053.11+00.05 MM1 at 1.7 kpc…
We present near-infrared and optical observations of the nova V496 Scuti 2009 covering various phases - pre-maximum, early decline and nebular - during the first 10 months of its discovery followed by limited observations in early part of…
Despite their large impact on stellar and galactic evolution, the properties of outflows from red supergiants are not well characterised. We used the Onsala 20m telescope to perform a spectral survey at 3mm and 4mm (68 - 116 GHz) of the red…
Near-infrared imaging of the emission from molecular hydrogen is a powerful method for discovering outflows in star-forming regions. We present new near-infrared images, long slit and integral field spectroscopy of the ultra-compact HII…
FU Orionis-type stars form a small class of variable Young Stellar Objects, defined by an optical outburst of 5-6 mag followed by gradual fading on a timescale of decades. Since the phenomenon is connected to the circumstellar medium the…
We present X-shooter at the Vewry Large Telescope observations of a sample of 10 luminous, X-ray obscured QSOs at z$\sim1.5$ from the XMM-COSMOS survey, expected to be caught in the transitioning phase from starburst to active galactic…
Variability is a characteristic feature of young stellar objects (YSOs) and could contribute to the large scatter observed in HR diagrams for star forming regions. For typical YSOs, however, the long-term effects of variability are poorly…
We present multi-frequency monitoring observations of the black hole X-ray binary V404 Cygni throughout its June 2015 outburst. Our data set includes radio and mm/sub-mm photometry, taken with the Karl G. Jansky Very Large Array, Arc-Minute…
Context. V2492 Cyg is a young eruptive star that went into outburst in 2010. The near-infrared color changes observed since the outburst peak suggest that the source belongs to a newly defined sub-class of young eruptive stars, where…