אודות פרק זה
Transcript: In a binary star the brighter or more massive star is usually called A, and the fainter or less massive star is called B. Castor A and Castor B is an example. The most common type of binary is a visual binary. Visual binaries can be resolved by a telescope. The separate images can be tracked over a period of months or years with images that show the orbit directly. The space motion is derived from a combination of the motion on the plane of the sky, the transverse velocity, with the radial motion measured by the Doppler Effect. Together these give the three dimensional space velocity. Most visual binaries have separations of about ten to twenty astronomical units. Over a hundred thousand are known. At a distance beyond about twenty parsec, at these typical separations visual binaries become unresolved, and sometimes one member of a visual binary is at the limit of a telescope’s observation and so the second motion must be inferred from the first.
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חיפוש פרקים ישנים
חפש פרקים קודמים של 17. Galactic Mass Distribution and Galaxy Structure.
פרקים אחרים בפודקאסט הזה
Transcript: Most binary stars orbit slowly with a large distance between the two stars. However, a small fraction of binary systems are in close, tight, rapid orbits. In this situation mass transfer can occur from one star to the other. The system of two co-orbiting stars is surrounded by two t…
Transcript: It’s a great challenge to determine the true incidence of binary and multiple star systems. The nearest stars are well observed, but it’s a very small sample. As we go to more distant stars a faint companion might not be detectable. Spectroscopic binaries are biased towards small se…
Transcript: How does mass transfer occur in a close binary pair? The Roche surface or lobes define the region of space where gas is bound to one or both stars. If either star becomes a giant the outer layers swell to fill the lobe, and the teardrop shape becomes the actual surface of the star. …
Transcript: Consider a binary pair where the more massive star has expanded to fill its Roche lobe, and the smaller star is a white dwarf of nearly 1.4 solar masses. As the massive star dumps hydrogen onto the white dwarf the gas is compressed, rapidly heated, and it ignites nuclear reactions tha…
Transcript: Consider a binary system where a giant or a supergiant star is in orbit around a white dwarf and where a mass transfer between the lobes pushes the white dwarf over the Chandrasekhar limit. At this point the white dwarf collapses catastrophically to form either a neutron star or a bla…
הצהרה: הפודקאסט והגרפיקה המוטבעים בדף זה הם מ-Dr. Christopher D. Impey, Professor, Astronomy, שהוא רכושו של בעליו ואינו קשור או מאושר על ידי Listen Notes, Inc.
