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Planetary nebula - Wikipedia

en.wikipedia.org/wiki/Planetary_nebula

A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula ... After most of the red giant's atmosphere is dissipated, the ultraviolet radiation of .... This led to ...

Essential Cosmic Perspective Chapter 12 Flashcards | Quizlet

quizlet.com/59378845/essential-cosmic-perspective-chapter-12-flash-cards/

Explain why degeneracy pressure can support a stellar core against gravity even when the ... What happens to the core of a star after a planetary nebula occurs?

Background: Life Cycles of Stars - Imagine the Universe! - NASA

imagine.gsfc.nasa.gov/teachers/lessons/xray_spectra/background-lifecycles.html

May 7, 2015 ... As the main sequence star glows, hydrogen in its core is converted into helium by nuclear fusion. ... A planetary nebula is formed by the outer layers. ... However, their life cycles start to differ after the red giant phase. ... What happens between the red giant phase and the supernova explosion is described ...

The Stellar Life Cycle: Planetary Nebula + White Dwarf

cse.ssl.berkeley.edu/bmendez/ay10/2000/cycle/planetarynebula.html

It gets to the point where the star loses gravitational hold on its outer layers and they get pushed away the pressure exerted by the stellar wind and by the photons leaving the core. ... These shed outer layers are called a planetary nebula. ... or if the companion is too small or too far away, no accretion will occur, and it will be ...

The Life of a Star

www.astro.keele.ac.uk/workx/starlife/StarpageS_26M.html

Stars are hot bodies of glowing gas that start their life in Nebulae. ... now starts to contract further and reactions begin to occur in a shell around the core. ... core as a gaseous shell, this gas that surrounds the core is called a Planetary Nebula.

Stellar Evolution

www.uni.edu/morgans/astro/course/Notes/section2/new8.html

What happens to the Earth when the Sun starts to "die"? What is .... When the core temperature reaches 100 million K, it is hot enough for helium fusion to occur. ..... All that is left of the star after the Planetary Nebula stage is the hot little core.

Stellar Death - University of Oregon

abyss.uoregon.edu/~js/ast122/lectures/lec18.html

... this mass limit. An example of this is the Cat's Eye Nebula shown below: ... Even higher mass stars will burn neon after carbon is used up. ... Iron can fuse, but it absorbs energy in the process and the core temperature drops. ... This entire process happens so fast that we can only follow it using supercomputer simulations.

Life Cycles of Stars - UWGB Home

www.uwgb.edu/dutchs/AstronNotes/STARS.HTM

Mar 26, 1998 ... In addition, astronomers can calculate what would happen to stars .... look disk- like in a telescope, they are called planetary nebulae. Some giants are massive enough to start other cycles of nuclear reactions after their helium runs out; ... When helium begins to fuse in the sun's core, the outer gases of the ...

Page 1 @ Helium-burning supergiant: Helium fusion begins when ...

astro.swarthmore.edu/astro1/reading/Bennett_Ch17_pt2.pdf

What happens to a low-mass star after it exhausts its core helium? ... after a planetary nebula occurs? because one day the Sun will blow up as a supernova. 9.

The Cosmic Perspective Star Stuff

www.astro.gsu.edu/~martens/ASTRO1020-Spring2016/17_ReadingQuiz_Clickers.pdf

How does a star's mass affect nuclear fusion? ... a) hydrogen fusion will begin in a shell around the core. b) helium will begin to fuse ... What is a planetary nebula ? ... What happens in a high-mass star after it stops ... b) A helium flash occurs.