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Post Info TOPIC: Binary Stars
Blobrana


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Title: Light deflection in binary stars
Authors: Sven Zschocke

The light deflection of one component of a binary system due to the gravitational field of the other component is investigated. While this relativistic effect has not been observed thus far, the question arises that whether this effect becomes detectable in view of todays high-precision astrometry which soon will reach the microarcsecond level of accuracy. The effect is studied and its observability is investigated. It turns out, that in total there are about 1000 binaries having orbital parameters such that the light deflection amounts to be at least 1 microarcsecond. Two stringent criteria for the orbital parameters are presented, by means of which one can easily determine the maximal value of light deflection effect for a given binary system. It is found, that for relevant binaries their orbital parameters must take rather extreme values in order to have a light deflection of the order of a few microarcseconds. Only in a very few and rather extreme binary systems the light deflection effect might be detectable by todays astrometry, but their existence is highly improbable. Thus, the detection of this subtle effect of relativity still remains a challenge for future astrometric missions.

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Blobrana


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Our sun may be an only child, but most of the stars in the galaxy are actually twins. The sibling stars circle around each other at varying distances, bound by the hands of gravity.
How twin stars form is an ongoing question in astronomy. Do they start out like fraternal twins developing from two separate clouds, or "eggs? Or do they begin life in one cloud that splits into two, like identical twins born from one egg? Astronomers generally believe that widely spaced twin, or binary, stars grow from two separate clouds, while the closer-knit binary stars start out from one cloud. But how this latter process works has not been clear.
New observations from NASA's Spitzer Space Telescope are acting like sonograms to reveal the early birth process of snug twin stars. The infrared telescope can see the structure of the dense, dusty envelopes surrounding newborn stars in remarkable detail. These envelopes are like wombs feeding stars growing inside -- the material falls onto disks spinning around the stars, and then is pulled farther inward by the fattening stars.
The Spitzer pictures reveal blob-like, asymmetrical envelopes for nearly all of 20 objects studied. According to astronomers, such irregularities might trigger binary stars to form.
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Blobrana


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Eclipsing Binary I
Eclipsing Binary II



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Blobrana


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Spectroscopic Binary



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Blobrana


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Title: Orbits Of Five Visual Binary Stars
Authors: Bojan Novakovic

We presented here the orbital parameters for five visual binary stars calculated by using the new method which we named Sector Grid Search. Orbital parameters were obtained for the following stars: WDS 00152+2722 = ADS 195, WDS 02202+2949 = ADS 1780, WDS 11550-5606 = HIP 58106, WDS 16256-2327 = ADS 10049 and WDS 16256-2327 = ADS 10045. In addition, their masses, dynamical parallaxes and ephemerides were calculated as well.

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