Related papers: BZ Cam during its 1999/2000 optical low state

HST and ground-based [OII} and [NII] images obtained from 1996 to 1999 reveal the existence of a ionised optical nebula around the symbiotic binary CH Cyg extending out to 5000 A.U. from the central stars. The observed velocity range of the…

Four VY Scl-type nova-like systems were observed in X-rays both during the low and the high optical states. They are BZ Cam, MV Lyr, TT Ari, and V794 Aql. Using archival ROSAT, Swift and SUZAKU observations we found that the X-ray flux for…

Aims. Numerous planetary nebulae show complicated inner structures not obviously explained. For one such object we undertake a detailed 3D photoionization and kinematical model analysis for a better understanding of the underlying shaping…

High-resolution optical spectra of the B[e] star CI Cam were obtained on arbitrary dates 2002-2023 using the echelle spectrograph NES of the 6-m BTA telescope. The temporal variability of the powerful emissions of H$\alpha$ and HeI profiles…

We report the results of 24 years of photometric and spectroscopic monitoring of CI Cam since its outburst in 1998. In the early years of our research, we identified a system component responsible for the emission of the He II 4686 line,…

PY Per has been known as a Z Cam star. Using VSOLJ, VSNET, AAVSO, ASAS-SN and ZTF observations, I found that this object experienced faint states and classified it to be a Z Cam + VY Scl star. Furthermore, the object changed the outburst…

We analyse the remnants of CK Vul (Nova Vul 1670) using optical imaging and spectroscopy. The imaging, obtained between 1991 and 2010, spans 5.6% of the life-time of the nebula. The flux of the nebula decreased during the last 2 decades.…

We obtained high dispersion spectra of CI Cam, the optical counterpart of XTE J0421+560, two weeks after the peak of its short outburst in 1998 April. The optical counterpart is a supergiant B[e] star emitting a two-component wind. The cool…

We present radio imaging observations of the 1998 outburst of the peculiar emission line star CI Cam, taken about 1, 4, 75, 82, 93, 163, and 306 days after the beginning of the 31.64 March 1998 X-ray flare. The first two epochs show a…

(Shortened) Sequences of spectra of the nova-like cataclysmic variable (CV) BZ Cam were acquired on 9 nights in 2005-2006 in order to study the time development of episodes of wind activity known to occur frequently in this star. We confirm…

Results of optical spectral monitoring of CI Cam just after its a unusual bright and rapidly evolving X-ray burst are reported. This star is a symbiotic-type X-ray binary. The X-ray-radio-optical burst and the appearance of relativistic…

We present here the spectrum of the galaxy companion to the z=4.7 quasar BR1202-0725, in the optical range 6000-9000 A, corresponding to 1050-1580 A rest-frame. We detect a strong Lya emission line at z=4.702, with an integrated flux of…

Short-period high-amplitude pulsating stars of Population I ($\delta$ Sct stars) and II (SX Phe variables) exist in the lower part of the classical (Cepheid) instability strip. Most of them have very simple pulsational behaviours, only one…

We combine archival spectral observations of the LBV star V532 (Romano's star) together with the existing photometric data in the B band. Spectroscopic data cover 15 years of observations (from 1992 to 2007). We show that the object in…

Through a program of narrow band imaging, we have observed the changing structure of the H alpha emission line around Nova Cyg 1992 (V1974 Cyg) at regular intervals from 1996 to 1999. Between 1994 and 1996, the nebular boundary advanced to…

BZ Cam is the first cataclysmic variable star with an accretion disk wind evident in its optical spectrum. The wind was found by Thorstensen, who discovered intermittent P Cygni profiles occurring simultaneously in He I 5876 Angstroms and H…

We present an analysis of spectrophotometric observations of the latest cycle of activity of the symbiotic binary Z And from 2006 to 2010. We estimate the temperature of the hot component of Z And to be \approx 150000 - 170000 K at minimum…

We present radial velocities of the M8V-type, very low-mass star vB 10 that have been obtained at four different epochs of observations between 2001 and 2008. We use high-resolution (R ~ 20,000) near-infrared (J-band) spectra taken with the…

Using VSNET, VSOLJ, ASAS-SN and ATLAS observations, I found that the Z Cam star PY Per spent a long, faint low state reaching 19.1 mag at least between 2022 June and November. No dwarf nova outburst was recorded during this interval. TESS…

We present high-dispersion spectroscopic data of the compact planetary nebula Vy 1-2, where high expansion velocities up to 100 km/s are found in the Ha, [N II] and [O III] emission lines. HST images reveal a bipolar structure. Vy 1-2…