• Study Resource
  • Explore Categories
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
Your Place in Space and Time
Your Place in Space and Time

... a few dozen galaxies, such as our own Local Group, or larger clusters containing up to a few thousand galaxies. ...
Week 11
Week 11

... FUSION: small nuclei combine together IF they collide fast enough • example: hydrogen ...
Cat`s Eye Nebula (NGC 6543)
Cat`s Eye Nebula (NGC 6543)

... determine whether their students harbor any of them. Students may have misconceptions regarding the evolution and fate of stars.The name planetary nebula in itself is misleading. Students may think that planetary nebulae are associated with planets, when, in fact, they have nothing to do with them. ...
How do atoms interact with light?
How do atoms interact with light?

... This chapter marks a change in the way you will look at nature. Up to this point, you have been thinking about what you can see with your eyes alone or aided ...
DR 19.2 - Cobb Learning
DR 19.2 - Cobb Learning

... ______ 21. stars with low mass, low temperature, and low absolute magnitude ______ 22. small hot stars that are dimmer than the sun ______ 23. high-temperature stars that quickly use up their hydrogen ______ 24. cool stars with absolute magnitude ______ 25. stars in the band that runs along the midd ...
White Dwarfs and the age of the Universe
White Dwarfs and the age of the Universe

... the role of gravity •  mass attracts other mass •  all parts of star gravitationally attract all other parts of star •  result: all objects squeeze themselves how does force of gravity change as star squeezes itself? INCREASES ...
The Birth of Stars and Planets
The Birth of Stars and Planets

... • Molecular clouds are intermittent phenomena Cloud support on long timescales irrelevant • Supersonic flows in the low-density ISM medium ⇒ Regions of enhanced density • Collapse criterion fullfilled only in small volumes of a cloud, but here on free-fall timescale ...
Chapter 22
Chapter 22

... 22.2 Stars change over their life cycles. ...
AST101_lect_13
AST101_lect_13

... Stars evolve up and to left in MS (but not much) Solar luminosity has increased by 30% in 4.6 Gyr ...
AST101 Lecture 13 The Lives of the Stars
AST101 Lecture 13 The Lives of the Stars

... Stars evolve up and to left in MS (but not much) Solar luminosity has increased by 30% in 4.6 Gyr ...
Astronomy 101 Course Review and Summary
Astronomy 101 Course Review and Summary

... Matter can come in various forms that are composed of fundamental particles An element is known by it number of protons Isotopes of an element contain different number of neutrons Isotopes can be radioactive and spontaneously decay There are four fundamental forces (Gravity, Electromagnetism, Strong ...
The Butterfly Nebula (NGC 6302)
The Butterfly Nebula (NGC 6302)

... beautiful shapes of planetary nebulae. Finally, the remnant star at the center settles down into an object about the size of the Earth, called a “white dwarf.” The Butterfly Nebula, catalogued as NGC 6302, was ejected from a dying star that was once about five times the mass of the Sun. After about ...
Variable Stars: Pulsation, Evolution and applications to Cosmology
Variable Stars: Pulsation, Evolution and applications to Cosmology

... Recall equations of stellar structure. Nuclear energy generation rate ε(ρ,T) slowly changes the composition decreasing the amount of Hydrogen and increasing the amount of Helium on a nuclear time scale – the characteristic time for stellar properties to change as a result of nuclear burning: tnuc ~ ...
Sample multiple choice questions for Exam 2
Sample multiple choice questions for Exam 2

... 16. Most galaxies that we see display red shifts. This indicates a) there is a lot of material between the Sun and the galaxies b) most galaxies are moving away from us c) the Sun is orbiting around the center of the Milky Way d) the instruments we are using are in error e) something, but we haven't ...
Southern cross Crux - The Southern Cross Crux, the Southern Cross
Southern cross Crux - The Southern Cross Crux, the Southern Cross

... Acrux is a multiple star located 320 light years from the solar system. Only two components are visually distinguishable, α1 and α2 Cru, separated by 4.4". This pair can be resolved easily in a small telescope. α1 Cru is magnitude 1.40 and α2 Cru is magnitude 2.09, both hot class B1 V main sequence ...
Schedule for Spring 2013 SCI 103 Introductory Astronomy
Schedule for Spring 2013 SCI 103 Introductory Astronomy

... Relationship between the radius, temperature and luminosity of the Sun ...
Consider Average Stars
Consider Average Stars

... We now do better than the Greeks, measuring star brightnesses very precisely – so there are, for example, stars of magnitude 2.50, or 3.75. They are not merely put into ‘groups.’ Here are some real examples: ...
Telescopes (continued). Properties of Stars.
Telescopes (continued). Properties of Stars.

... Usually we measure apparent brightness in a small range of the complete spectrum. Eyes are sensitive to visible light. When we measure the apparent brightness in the visible region, we can calculate only the visiblelight luminosity. ...
Astronomy Library wk 6.cwk (WP)
Astronomy Library wk 6.cwk (WP)

... A more convenient unit to use, especially when measuring distances using parallax, is the Parsec: ...
7_Big_bang
7_Big_bang

... • Universe contains countless galaxies like Milky Way. • A single galaxy can have 100s of billions of stars. • Spectrum (characteristic frequencies) of star light similar ...
Deep Space Mystery Note Form 2
Deep Space Mystery Note Form 2

... A supernova can also be created when a white dwarf star has drawn enough material from a companion star to raise its core temperature enough to ignite carbon fusion. The violent explosion of a massive star makes the expanding gases to glow briefly and brightly. During this short interval, a superno ...
The winter triangle - NRC Publications Archive
The winter triangle - NRC Publications Archive

... 100,000 light years in diameter. That is, it is so large that light takes roughly 100,000 light years to get from one side to the other. In more familiar units, a light year is just under 10,000,000,000,000 km. The most distant galaxies we can see are more than ten billion light years away. The univ ...
Constellations - Jolie McLaine`s Senior Project
Constellations - Jolie McLaine`s Senior Project

... only the sacrifice of Andromeda to the monster could appease the wrath of the sea god. The king chained Andromeda to a sea cliff. Fortunately, at this same moment, Perseus, was traveling along the coast. Perseus noticed the beautiful woman and fell in love with her. Learning of Andromeda's story, he ...
Document
Document

... – Bulges formed like early ellipticals, smaller scale models of same: “dissipational collapse; – Discs form slowly from inflowing cold gas streams; – Accretion of satellites adds metal poor stars to halo and gas to disc; – Dynamical evolution can produce bars, thick discs, globular cluster in-fall a ...
Earth in the Universe Answer each in your binder or notebook. Date
Earth in the Universe Answer each in your binder or notebook. Date

... A. The galaxy’s stellar nebulae reflect the Sun’s light. B. Billions of stars in the galaxy carry out nuclear fusion. C. Tons of compressed matter begin to radiate visible light from the galaxy center. D. The galaxy spins at a speed that generates a large amount of molecular friction. ...
< 1 ... 113 114 115 116 117 118 119 120 121 ... 194 >

H II region



An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report