Related papers: V4332 Sagittarii revisited

We present photometric and spectroscopic optical and near-infrared (NIR) observations (Based on observations collected at the European Southern Observatory, Chile (ESO ID 63.H-0493 and 64.H-0382)) taken during the outburst of the…

We report on new modeling results based on the mm- to X-ray emission of the SgrA* counterpart associated with the massive black hole at the Galactic Center. Our modeling is based on simultaneous observations carried out on 07 July, 2004,…

V5116 Sgr (Nova Sgr 2005 No. 2), discovered on 2005 July 4, was observed with XMM-Newton in March 2007, 20 months after the optical outburst. The X-ray spectrum shows that the nova had evolved to a pure supersoft X-ray source, with no…

We have performed monitoring observations of the 3-mm flux density toward the Galactic Center compact radio source Sgr A* with the Australia Telescope Compact Array since 2005 October. Careful calibrations of both elevation-dependent and…

The ionized core in the Sgr B2 Main star-forming region was imaged using the Submillimeter Array archival data observed for the H26$\alpha$ line and continuum emission at 0.86 millimeter with an angular resolution 0.3\arcsec. Eight…

We present imaging polarimetry observations of the eruptive variable V838 Monocerotis and its neighboring field obtained in 2002 October. The polarization of field stars confirms the previously determined interstellar polarization along the…

As part of the Selected Areas Starcount Survey (SASS), a CCD survey to V>21, we have obtained VI photometry of two fields at b=+-40 aligned roughly with an extrapolation of the major axis of the Sagittarius (Sgr) dwarf spheroidal galaxy.…

We report spectroscopic and photometric follow-up of the peculiar nova V5852~Sgr (discovered as OGLE-2015-NOVA-01), which exhibits a combination of features from different nova classes. The photometry shows a flat-topped light curve with…

We report on the discovery of recently ionized hydrogen-deficient gas in the immediate circumstellar environment of the final helium shell flash star V4334 Sgr (Sakurai's object). On spectra obtained with FORS2 multi-object spectroscopy we…

Luminous Red Variables (LRVs) are most likely eruptions that are the outcome of stellar mergers. V838 Mon is one of the best-studied members of this class, representing an archetype for stellar mergers resulting from B-type stars. As result…

We present observations of SS 433 using the Chandra High Energy Transmission Grating Spectrometer. Many emission lines of highly ionized elements are detected with the relativistic blue and red Doppler shifts. The lines are measurably…

Starting in 2013 February, Swift has been performing short daily monitoring observations of the G2 gas cloud near Sgr A* with the X-Ray Telescope to determine whether the cloud interaction leads to an increase in the flux from the Galactic…

The flat spectrum radio quasar 1633+382 (4C~38.41) showed a significant increase of its radio flux density during the period 2012 March - 2015 August which correlates with gamma-ray flaring activity. Multi-frequency simultaneous VLBI…

We report the GMRT observations of V4641 Sgr during the May 2002 outburst at radio frequencies of 610 and 244 MHz. This is the lowest frequency radio detection of this source. The present low frequency radio observations clearly showed…

In June 2015, the source V404 Cygni (= GS2023+38) underwent an extraordinary outburst. We present the results obtained during the first revolution dedicated to this target by the INTEGRAL mission, and focus on the spectral behavior in the…

The black hole candidate V4641 Sgr (= SAX J1819.3-2525) went through a brief outburst during 2003 Aug 01 to Aug 08. During the outburst, activity was noted in optical, radio as well as X-rays. Here we present results of Spectral and…

We report on multiwavelength observations of the blazar PKS 0537-441 (z = 0.896) obtained from microwaves through gamma rays by SMA, REM, ATOM, Swift and Fermi during 2008 August-2010 April. Strong variability has been observed in gamma…

The 30-year recurrent symbiotic nova V3890 Sgr exploded 2019 August 28 and was observed with multiple X-ray telescopes. An XMM-Newton observation during the SSS phase captured a high degree of X-ray variability including a deep dip in the…

Since the Fermi discovery of $\gamma$-rays from novae, one of the biggest questions in the field has been how novae generate such high-energy emission. Shocks must be a fundamental ingredient. Six months of radio observations of the 2012…

Observations of SS433 by INTEGRAL carried out in March -- May 2003 are presented. SS433 is evidently detected on the INTEGRAL images of the corresponding sky region in the energy bands 25-50 and 50-100 keV. The precessional variability of…