เกี่ยวกับตอนนี้
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 that blow off a shell of gas. The resulting emission is called a nova. This process is cyclic because gas can then accumulate again, and on a time scale ranging from a hundred to ten thousand years a new cycle of gas flow, compression, ignition, and blowing off occurs. It’s not exactly periodic, but the flaring up of a star in a nova event is spectacular because the brightness can increase by several orders of magnitude. Roughly thirty to fifty novae are seen per year among the several hundred million stars in the Milky Way galaxy. Nova stands for new stars; these are some of the most prominent events in recorded history in astronomy.
ภาษาอังกฤษ
สหรัฐอเมริกา
สำเนาบทสนทนา 🔗
Are you the producer of this podcast?
Add a podcast transcript
Need Audio-to-Text?
Transcribe with Listen411 in Just 60 Seconds
ค้นหาตอนที่ผ่านมา
ค้นหาตอนที่ผ่านมาของ 17. Galactic Mass Distribution and Galaxy Structure
ตอนอื่นๆ ใน PODCAST นี้
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 te…
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. I…
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 sep…
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 blac…
ข้อสงวนสิทธิ์: พอดแคสต์และอาร์ตเวิร์คที่ฝังอยู่ในหน้านี้มาจาก Dr. Christopher D. Impey, Professor, Astronomy ซึ่งเป็นทรัพย์สินของเจ้าของและไม่มีส่วนเกี่ยวข้องหรือรับรองโดย Listen Notes, Inc.
