scholarly journals The Massive Close Binary in the δ Ori A Triple System

2002 ◽  
Vol 187 ◽  
pp. 47-52
Author(s):  
James A. Harvin ◽  
Douglas R. Gies
Keyword(s):  
Cross Correlation ◽  
Short Wave ◽  
Close Binary ◽  
Full Description ◽  
High Dispersion ◽  
Orbital Elements ◽  
Primary Star ◽  
International Ultraviolet Explorer ◽  
Triple Star ◽  
Massive Close Binary

AbstractWe present an analysis of short-wave, high-dispersion ultraviolet spectra of the triple star δ Ori A from the International Ultraviolet Explorer Satellite’s (IUE) Final Archive. These spectra were cross-correlated against AE Aur to find the components’ radial velocities, which were then used to produce the system’s orbital elements. The long-period tertiary star in the δ Ori A system was not seen in the resulting cross-correlation functions (CCFs). The close binary’s eclipses allow the orbit’s inclination to be estimated by modeling of its Hipparcos light curve. The primary star appears to have a mass of 11.2 M⊙ and the secondary seems to have a mass of 5.6 M⊙, both of which are about 1/3 of the expected values for stars of their MK types. Although we expected the massive close binary in the δ Ori A system to be a pre-Roche lobe overflow (RLOF) system, these masses appear to require that it be a post-RLOF system. The full description of this work, including the tomographic separation of the spectra for the close binary’s components, appears in Harvin et al. (2002).

scholarly journals Two Types of Evolution of Massive Close Binary Systems

1976 ◽  
Vol 73 ◽  
pp. 27-34 ◽  
Author(s):  
C. De Loore ◽  
J. P. De Greve
Keyword(s):  
Mass Exchange ◽  
Binary Systems ◽  
Supernova Explosion ◽  
Close Binary ◽  
Helium Burning ◽  
Primary Star ◽  
Close Binary Systems ◽  
First Case ◽  
Initial Chemical Composition ◽  
Massive Close Binary

It is well known that the outcome of case B evolution of the primaries of massive close binary systems (M1 ≥ 9 M⊙) depends on the initial primary mass. The most massive primaries finally ignite carbon, form iron cores and presumably end in a supernova explosion, whereas the lighter ones presumably end as white dwarfs, without carbon ignition. This paper derives an estimate of the mass boundary separating these two kinds of evolution.As an example of the first case, the evolution of a 20 M⊙ + 14 M⊙ system was computed; after the mass exchange, the primary star (with M = 5.43 M⊙) evolves through the helium-burning (Wolf-Rayet) stage towards a supernova explosion; finally the system evolves into an X-ray binary (BWRX-evolution).As a representative for the second case the evolution of a 10 M⊙ + 8 M⊙ system was examined. After the first stage of mass exchange, the primary (with a mass of 1.66 M⊙) approaches the helium main sequence; during later phases of helium burning the radius increases again, and a second stage of mass transfer starts; after this the star (with a mass of 1.14 M⊙) again evolves towards the left in the Hertzsprung-Russell diagram and ends as a white dwarf (BSWD-evolution). A system of 15 M⊙ + 8 M⊙ is found to evolve very similar to the 20 M⊙ + 14 M⊙ system. The mass Mu, separating the two types of evolution, must therefore be situated between 10 and 15 solar masses. An initial chemical composition X = 0.70, Z = 0.03 was used for all systems.

Case a evolution of massive close binary systems

1987 ◽  
Vol 134 (1) ◽  
pp. 161-176 ◽  
Author(s):  
Masaomi Nakamura ◽  
Yasuhisa Nakamura
Keyword(s):  
Binary Systems ◽  
Close Binary ◽  
Close Binary Systems ◽  
Massive Close Binary

scholarly journals Ultraviolet Observations of Some Close Binary Systems by the Astronomical Netherlands Satellite-Ans

1976 ◽  
Vol 73 ◽  
pp. 213-223
Author(s):  
Chi-Chao Wu
Keyword(s):  
Binary Systems ◽  
Hot Spot ◽  
Close Binary ◽  
Spectral Energy ◽  
Dwarf Novae ◽  
Energy Distributions ◽  
Primary Star ◽  
Higher Temperature ◽  
Far Ultraviolet ◽  
Ultraviolet Observations

Observations of δ Pic, a β Lyr type of eclipsing binary and seven dwarf novae are reported. The ultraviolet light curves of δ Pic indicate the accumulation of matter at the triangular Lagrangian points L4 and L5, the presence of a hot spot and a higher temperature for the primary star. The implication is that the cooler secondary fills its Roche lobe and is transfering mass to the primary; mass loss to the circumstellar space and possibly to the system may also be appreciable. The temperatures of dwarf novae are derived by comparing their ultraviolet spectral energy distributions with those for normal stars of luminosity classes IV and V. Piecing together observations for different objects, the SSCyg systems have temperatures of 28 500 K, 10 000 K and 9500 K, respectively, when they are at minimum, immediately before outburst and at the beginning of rise to maximum. At maximum, the temperature is 22 500 K or 17 300 K depending on the interstellar reddening correction for AR And. Immediately before outburst, there is a large excess of flux in the far ultraviolet as indicated by the large value of the ratio of flux at 1550 Å to that at 1800 Å. The observations of Z Cam during standstill gives a temperature of 14 900 K. No excess of flux in the far ultraviolet was observed during the maximum of AR And and the standstill of Z Cam.

scholarly journals Apsidal motion in massive close binary systems – I. HD 165052, an extreme case?

2013 ◽  
Vol 433 (2) ◽  
pp. 1300-1311 ◽  
Author(s):  
G. Ferrero ◽  
R. Gamen ◽  
O. Benvenuto ◽  
E. Fernández-Lajús
Keyword(s):  
Binary Systems ◽  
Extreme Case ◽  
Close Binary ◽  
Apsidal Motion ◽  
Close Binary Systems ◽  
Massive Close Binary

scholarly journals V479 And: CV, LMXB, or Symbiotic?

2011 ◽  
Vol 7 (S281) ◽  
pp. 113-116
Author(s):  
Diego González Buitrago ◽  
Gagik Tovmassian ◽  
Juan Echevarría ◽  
Sergey Zharikov ◽  
Takamitsu Miyaji ◽  
...  
Keyword(s):  
Orbital Period ◽  
Main Sequence ◽  
Compact Object ◽  
Close Binary System ◽  
Close Binary ◽  
Stellar Winds ◽  
Primary Star ◽  
Giant Star ◽  
X Ray ◽  
Low Mass

AbstractV479 And is a 14.26 hour, close binary system, comprised of a G8-K0 star departing from the main sequence and a compact primary star accreting matter from the donor. The object is an X-ray source, modulated with the orbital period. This, and the presence of an intense He II line, leads us to speculate that the compact object is a magnetic white dwarf. However, we do not find strong constraints on the upper mass limit of the compact object, and we may have a neutron star in a low mass X-ray binary instead of a cataclysmic variable. The orbital period is certainly too short for the donor star to be an evolved giant star, so classifying this object as a symbiotic binary may be a big stretch; however there is an evidence that the mass transfer occurs via stellar winds, rather than through the L1 point of Roche filling secondary, a phenomenon more common for symbiotic stars.

scholarly journals The Eclipses of the Close Binary Star BE UMa

1996 ◽  
Vol 158 ◽  
pp. 471-472
Author(s):  
Janet H. Wood ◽  
E. L. Robinson ◽  
E.-H. Zhang
Keyword(s):  
Light Curve ◽  
High Speed ◽  
Binary Star ◽  
Light Curves ◽  
Close Binary ◽  
Primary Star ◽  
Secondary Star ◽  
Different Depths ◽  
The Mean ◽  
Close Binary Star

BE UMa is a close binary star, not transferring mass, with an extremely hot primary star irradiating the inner face of the cool secondary star. The light curve shows a large-amplitude, sinusoidal variation with a period of 2.29 d, and an eclipse that is centered on the minimum of the variation [1], [3]. According to [1], the eclipse is partial, not total. However, it has been argued [2] that the eclipse was really flat bottomed and thus total. This has important repercussions for the deduced model of the system. To resolve this issue we obtained simultaneous UBVR photometry of BE UMa using the Stiening 4-channel, high-speed photometer on the 82-inch telescope at McDonald Observatory. The mean light curves are shown in Fig. 1. The eclipse in all colours is round bottomed and partial. The different depths are caused by the different contribution from the red secondary star in each bandpass.

scholarly journals Analysis of IUE spectrograms for Be stars

1994 ◽  
Vol 162 ◽  
pp. 280-281
Author(s):  
T. Eversberg ◽  
J. Dachs ◽  
T. W. Berghöfer ◽  
C. Huilai ◽  
U. Lemmer
Keyword(s):  
Short Wavelength ◽  
High Dispersion ◽  
Be Stars ◽  
Shell Type ◽  
International Ultraviolet Explorer ◽  
Optical Region

Archival high-dispersion spectrograms obtained by the International Ultraviolet Explorer satellite in the short-wavelength (λλ1150–2000Å) region were inspected and analyzed for a total of 33 Be stars, including one Oe star (HR 6397) and three stars showing shell-type spectra in the optical region (48 Lib, ɛ Cap, o Aqr). The following atomic and ionic transitions were investigated: Hi-Lyα, Cii-UV1, Ciii-UV4, Civ-UV1, Nv-UV1, Siii-UV1…-UV4, Siiii-UV2, Siiv-UV1.

scholarly journals Colliding Stellar Winds in O-type Close Binary Systems

1992 ◽  
Vol 135 ◽  
pp. 146-148
Author(s):  
D.R. Gies ◽  
M.S. Wiggs
Keyword(s):  
Binary Systems ◽  
Optical Emission ◽  
Emission Lines ◽  
Optical Observations ◽  
Close Binary ◽  
High Dispersion ◽  
Stellar Winds ◽  
Close Binary Systems ◽  
Circumstellar Gas ◽  
The Individual

In close binary systems of O-type stars, the individual stellar winds will collide between the stars to form shock fronts (Stevens et al. 1992). Binaries with equally luminous stars will have winds of comparable strength, and the shock will occur near the mid-plane between the stars, but in binaries of unequal luminosity, the interaction will occur along a bow shock wrapped around the star with the weaker wind. The presence of the shock region can be detected through excess X-ray emission (Chlebowski & Garmany 1990), and orbital phase-related variations in the UV P Cygni lines (Shore & Brown 1988) and optical emission lines (formed in high density regions of circumstellar gas).We have begun a search for colliding winds through a study of the optical emission lines and UV P Cygni lines in four massive binaries, AO Cas (Gies & Wiggs 1991), Plaskett’s star = HD 47129 (Wiggs & Gies 1992), 29 UW CMa and ι Ori. The optical observations consist of high S/N spectra of the Hα and He I λ6678 region obtained with the University of Texas McDonald Observatory 2.1-m telescope and coudé Reticon system. The UV observations were culled from archival IUE high dispersion spectra of several P Cygni features (N V λ1240, Si IV λ1400, C IV λ1550).

Tomographic Separation of Composite Spectra. X. The Massive Close Binary HD 101131

2002 ◽  
Vol 574 (2) ◽  
pp. 957-962 ◽  
Author(s):  
Douglas R. Gies ◽  
Laura R. Penny ◽  
Pavel Mayer ◽  
Horst Drechsel ◽  
Reinald Lorenz
Keyword(s):  
Close Binary ◽  
Composite Spectra ◽  
Massive Close Binary

scholarly journals IUE Studies of Hot Binary Stars

1992 ◽  
Vol 135 ◽  
pp. 393-395
Author(s):  
David J. Stickland
Keyword(s):  
Binary Stars ◽  
Storage Systems ◽  
Optical Disk ◽  
Public Access ◽  
High Dispersion ◽  
Disk Storage ◽  
International Ultraviolet Explorer ◽  
On Line ◽  
To Come ◽  
Reduced Data

The International Ultraviolet Explorer (IUE) was launched on 26th January 1978 and is still fully operational today, with several more years hopefully to come. After six months, the fully–reduced data is consigned to public–access archives maintained by the project agencies (NASA, ESA, and SERC). Thus, in addition to observations from current and future programmes, there are ~12,000 high–dispersion (Δλ ~ 0.15Å) spectra readily available now for research on stars hotter than about mid-B type. Furthermore, a uniform reprocessing, with optimum schemes, of all past IUE images has begun, to create the Final Archive which will be made accessible on–line through optical disk storage systems and will ensure the value of IUE data well into the future.

Sign in / Sign up

Export Citation Format

Share Document