• 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
NAME
NAME

... b. The velocity of stars stays approximately constant at distances well beyond the visible edges of galaxies, implying that galaxies contain much more matter than what we observe in stars and gas. c. The velocity of stars is low in the inner regions of galaxies, suggesting that dark matter is impedi ...
The Interstellar Medium (ISM) The Dust The Gas: a. The Hot
The Interstellar Medium (ISM) The Dust The Gas: a. The Hot

... High density: 105 per cm3 molecular hydrogen H2 . Cold Temperature: about 20K Molecular emissions formation of molecules — cool, low energy environment requires dust grains. Types of molecules Organic molecules; pre-biotic? possible detection of amino acid glycine Giant Molecular Clouds Massive,  ...
Astronomy
Astronomy

... 25. A visual representation of the temperature and luminosity of stars is called: 26. Relatively dark spots on the sun that contains intense magnetic fields are known as: 27. These reactions join the nuclei of atoms to form more massive nuclei: 28. Eruptions on the solar surface that return back to ...
Stars - White Plains Public Schools
Stars - White Plains Public Schools

... have a high, medium or low mass? ...
Spectral Class and Colour index
Spectral Class and Colour index

... Spectral Class and Colour index As we have seen the colour of a star is related to its temperature as a consequence of Wien’s law. λmaxT = constant The spectral class (OBAFGKM) of a main sequence star is also a direct result of its temperature. One (relatively crude) way of determining the temperatu ...
lifedeath - University of Glasgow
lifedeath - University of Glasgow

... When the fuel runs out: formation of a red giant ...
Twinkle, Twinkle, Little Star
Twinkle, Twinkle, Little Star

... appears from Earth. (depends on star’s distance from Earth) ...
Space - lucu
Space - lucu

... because they often look like planets due to their round shape. The outer shell of gas is usually illuminated by the remains of the star at its center. ...
September Evening Skies
September Evening Skies

... separation, are ζ UMa, δ Lyr, α Cap, ο Cyg, ε Lyr, ν Dra, ζ Lyr, β Cyg. ...
Life Cycle of a Star Notes
Life Cycle of a Star Notes

... together to form heavier elements such as helium and release energy. If enough matter is left behind, this may be so dense, and its gravitational field so strong that nothing can escape from it, not even light or other forms of electromagnetic radiation. It is then called a black hole. We cannot see ...
HW 5 Solutions What are “black smokers?” Where in our solar
HW 5 Solutions What are “black smokers?” Where in our solar

... discovered that some of the oldest life forms on earth live in these harsh environments. This was a revolution in our understanding of life, since these organisms gain their energy not from the sun but from the interior of the earth itself—geothermal energy. Black smokers, and with them possibly lif ...
Our Cosmic Neighborhood From our small world we have gazed
Our Cosmic Neighborhood From our small world we have gazed

... outward force generated by the fusion reactions are equal, the star remains stable. Clouds of gas are common in our galaxy and in other galaxies like ours. These clouds are called nebulae. A typical nebula is many light-years across and contains enough mass to make several thousand stars the size of ...
Whirlpool Galaxy - astronomydennis
Whirlpool Galaxy - astronomydennis

... At the center of the Whirlpool galaxy is its noted cross. The cross has been thought to have been caused by a jet of high speed plasma which confines radiation from the accretion disk to a pair of oppositely directed cones of light that ionize gas caught in their beams. In simple terms, it is the ab ...
Astrophysics 12 - Stellar Evolution
Astrophysics 12 - Stellar Evolution

... Pillars of Creation ...
The Hidden Lives of Galaxies NSTA 2001
The Hidden Lives of Galaxies NSTA 2001

... right (cold and faint). The Sun lies pretty close to the centre of this band. ...
What MSU Astronomers Will Do with the SOAR
What MSU Astronomers Will Do with the SOAR

... • Long-lived stars from just after initial round of star formation • Found by searches through huge samples • Then detailed follow-up observations with SOAR and other even larger telescopes ...
WK10revisedoneweek
WK10revisedoneweek

... sweeps out equal areas in equal times. 3. The ratio of the cube of the average radius of a planets orbit to the square of its orbital period of revolution is the same for ...
Red Giants and White Dwarfs
Red Giants and White Dwarfs

... • With no energy source, the core of the star resumes its collapse… • As it collapses, gravitational energy is again converted to thermal energy… • This heat allows fusion to occur in a shell of material surrounding the core… • Due to the higher central temperature, the star’s luminosity is greater ...
Ch. 21 notes-1
Ch. 21 notes-1

... They contain billions of stars but have little gas and dust. So they cannot form new star. They contain old stars. Irregular Galaxies Some galaxies do not have regular shapes. The Large Magellanic Cloud is an irregular galaxy about 160,000 light-years away from our galaxy. It is one of our clos ...
Astronomy 2
Astronomy 2

... blue → hottest 40,0000 F (30,000 K) ...
STARS
STARS

... • Most stars are between 1 billion and 10 billion years old. Some stars may even be close to 13.7 billion years old—the observed age of the universe. The oldest star yet discovered, HE 1523-0901, is an estimated 13.2 billion years old. • The more massive the star, the shorter its lifespan, primarily ...
Characteristics of Stars WS Questions 1-20
Characteristics of Stars WS Questions 1-20

... Answer all of the following questions by rephrasing and using complete sentences. If you do not rephrase or use complete sentences, you will automatically lose half of the points available. 1. If you could travel at the speed of light, how long would it take you to travel from Earth to the sun? ...
Document
Document

... 3. The temperature of the layer of gas that produces the visible light of the Sun is about _______. a) 15 million K, b) 300,000 K, c) 10 million K, d) 1 million K, e) 5800 K 4. What is the net result of the proton-proton chain? a) 2 heliums are fused into 1 carbon, 1 neutrinos + energy b) 4 hydrogen ...
Sammy Nagel · Annie Jump Cannon
Sammy Nagel · Annie Jump Cannon

... What were the contribution(s) that this individual made to science and/or a related field? She classified over 350000 stars.1.She also classified over 300 rare types of stars.2.Annie organized and collected photos for Harvard.3.She added over 300000 photos to their collection.4.Harvard had 200000 ph ...
Document
Document

... At the heart of the Orion Nebula lies a complex of molecular clouds where abundant star formation is occurring today. The clouds are illuminated by a flood of ultraviolet light emitted by four bright stars, collectively called the Trapezium. ...
< 1 ... 173 174 175 176 177 178 179 180 181 ... 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