• 40. When helium fusion begins in the core of a ...

    When helium fusion begins in the core of a red giant star, the situation quickly gets out of control because electrondegeneracy pressure does not respond to changes in. ... horizontal branch. e. white dwarf. 43. A star's surface temperature during the horizontal branch phase is determined primarily by its. a. luminosity. b. ...

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  • Astro 1A Midterm #2 Sample Questions

    B. a sudden onset of helium fusion reactions in red giant and supergiant stars of any mass. C. a sudden release of energy at the end of helium burning, due to core contraction. D. a sudden onset of helium fusion reactions in the core of a lowmass red giant star.

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  • Horizontal branch YouTube

    Sep 16, 2016· The horizontal branch is a stage of stellar evolution that immediately follows the red giant branch in stars whose masses are similar to the Sun' stars are powered by helium ...

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  • Sample Exam Questions: Chaisson Chapter 12

    B) helium fusion gives off more energy than does hydrogen. C) the core contracts, raising the temperature and hydrogen burning shell outward. D) it explodes as a nova. E) the helium flash increases the size of the star immensely. 5. A star is on the horizontal branch of the HR diagram. Which statement is true? A) It is burning both hydrogen and helium.

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  • * Horizontal branch star (Astronomy) Definition,meaning ...

    Horizontal branch star Horizontal Branch star s This is a phase of stellar evolution undergone by intermediatemass stars, those with masses M⊙ 8 M⊙, a range which encompasses the majority of stars in the Galaxy, including our Sun.

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  • Aristotle's Model of Communication | Mary Rose Nazareno ...

    The next concentration of stars is on the horizontal branch (helium fusion in the core and hydrogen burning in a shell surrounding the core). Another prominent feature is the Hertzsprung gap located in the region between A5 and G0 spectral type and between +1 and −3 absolute magnitudes ( between the top of the main sequence and the giants in the horizontal branch).

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  • Hertzsprung–Russell diagram Wikipedia, the free .

    Most of the stars occupy the region in the diagram along the line called the main sequence. During that stage stars are fusing hydrogen in their cores. The next concentration of stars is on the horizontal branch (helium fusion in the core and hydrogen burning in a shell surrounding the core).

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  • How do stars generate energy

    This is the horizontal branch (for population II stars) or red clump (for population I stars). After the completion of helium burning in the core, the star again moves to the right and upwards on ...

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  • Homework #5 1. The Helium Main Sequence

    e. We associate the horizontal branch" in the HR diagram with stars burning helium in their cores. But in part (c), the He main sequence you found wasn't horizontal. In the MESA portion of this problem, we will study more realistic horizontal branch stars. It turns out that it is easier to do so by evolving a stellar model in an unphysical" way.

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  • 5 Horizontal branch made because these helium core fusion ...

    5. Horizontal branch: made because these helium core fusion stars all have about the same luminosity but can differ in surface temperature. Stars that have previously experienced a helium flash and become helium core fusion stars. They are shorter, hotter, and less luminous. 6.

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  • The Cosmic Perspective Physics Astronomy

    – Hydrogen fusion in core (main sequence) – Hydrogen fusion in shell around contracting core (red giant) – Helium fusion in core (horizontal branch) – Double shell burning (red giant) • How does a lowmass star die? – Ejection of hydrogen and helium in a planetary nebula leaves behind an inert white dwarf.

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  • A.

    • "horizontal branch star" 4: Horizontal branch star He core burning, H shell burning Short phase, lasts ~50 MY Triplealpha fusion: 3 He C Helium flash He fusion to C in core (horizontal branch) HR diagram of globular cluster Discussion: "City of Stars": What does it tell us? Why is it useful? 5. Red Supergiant Doubleshell burning ...

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  • stellar evolution Does a star fuse helium to beryllium ...

    After some time, the core begins to contract, the outer envelope expands, and the star is said to be on the red giant branch. Eventually, temperatures rise to the point where the triplealpha process can occur, and a helium flash occurs, marking the beginning of the horizontal branch and helium fusion .

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  • Star Death I: Low Mass Stars Pennsylvania State University

    Red giant phase * Core hydrogen fusion stops * Core contracts, envelope swells * Hydrogen fusion in shell * Aldebaran 2. Horizontal branch * Helium fuses to carbon in core (triplealpha process) * Oxygen synthesized 3. Supergiant phase * No more core fusion * Heliumfusing .

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  • Astronomy: HR Diagram Washington State University

    Not a phase it's a nearinstantaneous event when helium fusion begins. Core temperature about 100 million K. Helium main sequence (also known as "red clump" if it hugs the giant branch, or "horizontal branch" if it spreads out to hotter temperatures). 2ndlongest phase. Roughly billion yr. Fuel: Core He fusion. Star is a stable red giant.

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  • Name: Period: Date: Astronomy Ch. Stellar Evolution

    A) in the middle of the main sequence stage B) when the T Tauri bipolar jets shoot out C) horizontal branch D) planetary nebula E) red giant 8) 9) During the hydrogen shell burning phase A) helium is burning in the core. B) the star grows more luminous. C) hydrogen is burning in the central core.

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  • The hottest horizontalbranch stars in ω Centauri. Late ...

    The Hottest HorizontalBranch Stars in ω Centauri – Late Hot Flasher vs. Helium Enrichment log nnHeH ≈0. . . 2 during most of the HB phase, in rough agree However, 40% – 30% of the stars above 30,000 K show helium ment with the heliumrich stars in Fig. 2.

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  • Chapter 18 Stars Physics and Astronomy

    Late stages of evolution: Red Giants, Horizontal Branch Stars, Asymptotic Giant Branch Stars, White Dwarfs. At each stage, what element is fusing and where? How does that change the structure of the star? The evolutionary path of the star on the HR diagram. How do . L, T, R. change at each stage?

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  • Horizontal branch Wikipedia

    Horizontal branch. The horizontal branch (HB) is a stage of stellar evolution that immediately follows the red giant branch in stars whose masses are similar to the Sun's. Horizontalbranch stars are powered by helium fusion in the core (via the triplealpha process) and by hydrogen fusion (via the CNO cycle) in a shell surrounding the core.

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