scholarly journals Simultaneous Multiwavelength Observations of Dwarf Novae Systems at Quiescence and in Outburst

1996 ◽  
Vol 158 ◽  
pp. 79-80
Author(s):  
G. Tovmassian ◽  
J. Echevarria ◽  
E. Perez ◽  
D. H. P. Jones ◽  
M. Shara ◽  
...  
Keyword(s):  
Dwarf Novae ◽  
Preliminary Results ◽  
International Program ◽  
Spectroscopic Observations ◽  
Photometric And Spectroscopic Observations ◽  
Photometric Observations ◽  
Northern And Southern Hemispheres ◽  
Multiwavelength Observations

The results of photometric and spectroscopic observations of dwarf novae are presented. The data were obtained during an international program of multiwavelength observations, held in 1986 February at several observatories, of dwarf novae during the first and subsequent days of outburst. During the campaign numerous dwarf novae were monitored in order to catch them in outburst. Preliminary results and analysis of some objects are reported elsewhere. A total of 30 dwarf novae were observed in the northern and southern hemispheres. Among them 37% were caught in outburst, including 10% on the rise to outburst and 17% in decline. Photometric observations were carried out in the UBVRI system and colour indexes were calculated.

scholarly journals An attempt of seismic modelling of β Cephei stars in NGC 6910

2014 ◽  
Vol 9 (S307) ◽  
pp. 222-223
Author(s):  
D. Moździerski ◽  
Z. Kołaczkowski ◽  
E. Zahajkiewicz
Keyword(s):  
Seismic Modeling ◽  
Preliminary Results ◽  
Spectroscopic Observations ◽  
Seismic Modelling ◽  
Photometric And Spectroscopic Observations

AbstractWe present preliminary results of seismic modeling of β Cephei-type stars in NGC 6910 based on simultaneous photometric and spectroscopic observations carried out in 2013 in Białków (photometry) and Apache Point (spectroscopy) observatories.

Recent Photometric and Spectroscopic Observations of Southern Dwarf Novae

1979 ◽  
Vol 46 ◽  
pp. 24-28
Author(s):  
N. Vogt
Keyword(s):  
Orbital Period ◽  
Special Interest ◽  
Dwarf Novae ◽  
Spectroscopic Observations ◽  
Photometric And Spectroscopic Observations ◽  
Cataclysmic Binaries

This contribution concerns three dwarf novae of special interest: one of them has the longest known orbital period of all dwarf novae (BV Cen); the remaining two variables (Z Cha and EX Hya) belong to the group of the ultra-short periodic cataclysmic binaries. Here only short summaries are given. The detailed results will be published elsewhere, in the case of BV Cen together with J. Breysacher, and in the case of EX Hya together with D. Comte, C. Sterken and W. Krzeminski.

scholarly journals First detection of two superoutbursts during the rebrightening phase of a WZ Sge-type dwarf nova: TCP J21040470+4631129

2020 ◽  
Vol 72 (3) ◽  
Author(s):  
Yusuke Tampo ◽  
Kojiguchi Naoto ◽  
Keisuke Isogai ◽  
Taichi Kato ◽  
Mariko Kimura ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Accretion Disk ◽  
Late Stage ◽  
Large Radius ◽  
Mass Ratio ◽  
Dwarf Novae ◽  
Dwarf Nova ◽  
Spectroscopic Observations ◽  
The Third ◽  
Photometric And Spectroscopic Observations

Abstract We report on photometric and spectroscopic observations and analysis of the 2019 superoutburst of TCP J21040470+4631129. This object showed a 9 mag superoutburst with early superhumps and ordinary superhumps, which are the features of WZ Sge-type dwarf novae. Five rebrightenings were observed after the main superoutburst. The spectra during the post-superoutburst stage showed Balmer, He i, and possible sodium doublet features. The mass ratio is derived as 0.0880(9) from the period of the superhump. During the third and fifth rebrightenings, growing superhumps and superoutbursts were observed, which have never been detected during a rebrightening phase among WZ Sge-type dwarf novae with multiple rebrightenings. To induce a superoutburst during the brightening phase, the accretion disk needs to have expanded beyond the 3 : 1 resonance radius of the system again after the main superoutburst. These peculiar phenomena can be explained by the enhanced viscosity and large radius of the accretion disk suggested by the higher luminosity and the presence of late-stage superhumps during the post-superoutburst stage, plus by more mass supply from the cool mass reservoir and/or from the secondary because of the enhanced mass transfer than those of other WZ Sge-type dwarf novae.

Models of Cataclysmic Variables from Photometric and Spectroscopic Data

1979 ◽  
Vol 46 ◽  
pp. 65-74 ◽  
Author(s):  
A.C. Fabian ◽  
J.E. Pringle ◽  
J.A.J. Whelan ◽  
J.A. Bailey
Keyword(s):  
Spectroscopic Data ◽  
Cataclysmic Variables ◽  
System Parameters ◽  
Dwarf Nova ◽  
Spectroscopic Observations ◽  
Photometric And Spectroscopic Observations

Abstract.Recent photometric and spectroscopic observations of the dwarf nova system Z Cha are discussed. Methods for constraining the system parameters are applied and the disc emissivity is deduced as a function of radius. Indications are found that the disc shrinks in size with increasing time after outburst.

scholarly journals V 3903 Sagitarii: A Main-Sequence (07V+09V) Detached Eclipsing Binary

1993 ◽  
Vol 137 ◽  
pp. 371-373
Author(s):  
L.P.R. Vaz ◽  
N.C.S. Cunha ◽  
E.F. Vieira ◽  
M.L.M. Myrrha
Keyword(s):  
Main Sequence ◽  
Eclipsing Binary ◽  
Spectroscopic Observations ◽  
Photometric And Spectroscopic Observations ◽  
Absolute Dimensions

AbstractPhotometric and spectroscopic observations of V3903 Sgr are analyzed, and absolute dimensions (masses and radii) are determined to a precision better then 3%.

scholarly journals On the Coronal and Prominence Structures Observed at the Total Solar Eclipse of 11 July 1991

1994 ◽  
Vol 154 ◽  
pp. 205-210
Author(s):  
Y. Suematsu ◽  
H. Fukushima ◽  
Y. Nishino
Keyword(s):  
Solar Eclipse ◽  
Near Infrared ◽  
Thermal Structure ◽  
Wavelength Region ◽  
Total Solar Eclipse ◽  
Preliminary Results ◽  
Spectroscopic Observations ◽  
Physical Conditions ◽  
Made In

Coronal images were taken in the light of the He I 10830 Å line, the 10000 Å continuum, and the Fe XIV 5303 Å line, with the aim of studying the thermal structure of the corona. In addition, spectroscopic observations were made in the violet wavelength region (3760-4060 Å) and near-infrared (10745-10835 Å), to obtain details of physical conditions of the corona, especially of its cool part. The data obtained do not show any distinct cool structures other than ordinary prominences. Some preliminary results concerning the corona and prominence structures are given.

scholarly journals New photometric and spectroscopic observations of the Seyfert galaxy Mrk 315

2005 ◽  
Vol 360 (1) ◽  
pp. 253-271 ◽  
Author(s):  
S. Ciroi ◽  
V. L. Afanasiev ◽  
A. V. Moiseev ◽  
V. Botte ◽  
F. Di Mille ◽  
...  
Keyword(s):  
Seyfert Galaxy ◽  
Spectroscopic Observations ◽  
Photometric And Spectroscopic Observations

scholarly journals Ultraviolet Observations of Cataclysmic Variables

1987 ◽  
Vol 93 ◽  
pp. 205-205 ◽  
Author(s):  
F. Verbunt
Keyword(s):  
Orbital Period ◽  
Cataclysmic Variables ◽  
Type Systems ◽  
Terminal Velocity ◽  
Dwarf Novae ◽  
Preliminary Results ◽  
System Type ◽  
International Ultraviolet Explorer ◽  
Flux Level ◽  
Ultraviolet Observations

AbstractThe preliminary results of the analysis of more than 1000 spectra of cataclysmic variables in the archive of the International Ultraviolet Explorer were presented at the meeting. To characterize the slope of the spectra I use F = log(f1460Å/f2880Å). For most spectra F lies between 0.2 and 0.7. No correlation of F with orbital period, inclination, system type or (for dwarf novae) length of the interoutburst interval are found, apart from somewhat lower values of F for DQ Her type systems. Out of 16 dwarf novae for which spectra both at outburst maximum and minimum are available 11 show no large difference in F between maximum and minimum, and in 5 F declines with the flux level. Out of 6 dwarf novae 5 show very red spectra during the rise to maximum, and 1 shows slopes during rise similar to those during decline.In the ultraviolet resonance lines, due to a wind from the disc, no correlation is found between inclination and terminal velocity.

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