reach for the stars
... 11. What is the Sun’s spectral class? (1 pt) G2V [G] 12. What is the Sun’s absolute magnitude? (1 pt) Accept 4.8 to 4.9 13. At what distance are apparent and absolute magnitude the same? (1 pt) 10 parsecs [32.6 ...
... 11. What is the Sun’s spectral class? (1 pt) G2V [G] 12. What is the Sun’s absolute magnitude? (1 pt) Accept 4.8 to 4.9 13. At what distance are apparent and absolute magnitude the same? (1 pt) 10 parsecs [32.6 ...
Luminosity
... • What is the significance of the main sequence? — Normal stars that fuse H to He in their cores fall on the main sequence of an H-R diagram. — A star’s mass determines its position along the main sequence (high mass: luminous and blue; low mass: faint and red). ...
... • What is the significance of the main sequence? — Normal stars that fuse H to He in their cores fall on the main sequence of an H-R diagram. — A star’s mass determines its position along the main sequence (high mass: luminous and blue; low mass: faint and red). ...
Oct 06, 2001
... This is a” thinking” question: Star A appears brighter than Star B, but Star A actually gives off less energy than Star B. The apparent magnitude and absolute magnitudes for Star A are m = 1 and M = -2, respectively. Use this information to answer the following two questions. 13) Which of the follow ...
... This is a” thinking” question: Star A appears brighter than Star B, but Star A actually gives off less energy than Star B. The apparent magnitude and absolute magnitudes for Star A are m = 1 and M = -2, respectively. Use this information to answer the following two questions. 13) Which of the follow ...
ASTRONOMY 313
... 10. Two galaxies separated by 600 kpc are orbiting each other with a period of 40 billion years (4 × 1010 years). What is the total mass of the two galaxies? [Hint: 1 parsec = 206265 A.U.] ...
... 10. Two galaxies separated by 600 kpc are orbiting each other with a period of 40 billion years (4 × 1010 years). What is the total mass of the two galaxies? [Hint: 1 parsec = 206265 A.U.] ...
Galactic astronomy - Sierra College Astronomy Home Page
... Pure H & He stars, the first stars born after the Big Bang when very little metals existed. Stellar models tell us that Pop III stars would have been massive, shortlived, and none would have survived to current times. ...
... Pure H & He stars, the first stars born after the Big Bang when very little metals existed. Stellar models tell us that Pop III stars would have been massive, shortlived, and none would have survived to current times. ...
Hertzsprung-Russell Diagram—key to understanding properties of stars. 26 Sept
... • You are a young astronomer in 1890, and you want to study stars. The distances to a few dozen stars are known. How do you attack this problem? • New developments in 1890 – Spectrometers analyze the colors of light – Photographic plates allow imaging of a large number of stars. ...
... • You are a young astronomer in 1890, and you want to study stars. The distances to a few dozen stars are known. How do you attack this problem? • New developments in 1890 – Spectrometers analyze the colors of light – Photographic plates allow imaging of a large number of stars. ...
THE MILKY WAY GALAXY
... Distances to globular clusters and the Andromeda nebula were determined using the newly discovered period-luminosity relation for certain variable stars. The derived distances proved that the Milky Way was an “island universe” of stars, similar to other nebulae seen all around the sky. The MW is c ...
... Distances to globular clusters and the Andromeda nebula were determined using the newly discovered period-luminosity relation for certain variable stars. The derived distances proved that the Milky Way was an “island universe” of stars, similar to other nebulae seen all around the sky. The MW is c ...
Stars PowerPoint
... • The Sun contains most of the mass in the solar system and is made up primarily of hydrogen and helium. • Astronomers learn about conditions inside the Sun by a combination of observation and theoretical models. • The Sun’s atmosphere consists of the photosphere, the chromosphere, and the corona. • ...
... • The Sun contains most of the mass in the solar system and is made up primarily of hydrogen and helium. • Astronomers learn about conditions inside the Sun by a combination of observation and theoretical models. • The Sun’s atmosphere consists of the photosphere, the chromosphere, and the corona. • ...
• This chapter concentrates on five goals:
... • Two, in the surface layers of stars hotter than about 20,000 K, there are many violent collisions between atoms. • These excite electrons to high energy levels or knock the electrons completely out of most atoms—so they become ionized. – In this case, few hydrogen atoms will have electrons in the ...
... • Two, in the surface layers of stars hotter than about 20,000 K, there are many violent collisions between atoms. • These excite electrons to high energy levels or knock the electrons completely out of most atoms—so they become ionized. – In this case, few hydrogen atoms will have electrons in the ...
Ay 112 Midterm review
... Depending on the temperature, different ionization states are present and lines have different strengths in the spectrum. This gives us another way to determine the photospheric temperature (besides Wiens law ...
... Depending on the temperature, different ionization states are present and lines have different strengths in the spectrum. This gives us another way to determine the photospheric temperature (besides Wiens law ...
Star Clusters and Stellar Dynamics
... energy amongst themselves. If at some moment a star becomes unbound (kinetic + potential energy > 0) then it will escape the cluster entirely. Evaporation time tevap ~ 100 trelax , and although long, it limits the cluster lifetime. Evaporation is accelerated by tidal shocks, which implant additional ...
... energy amongst themselves. If at some moment a star becomes unbound (kinetic + potential energy > 0) then it will escape the cluster entirely. Evaporation time tevap ~ 100 trelax , and although long, it limits the cluster lifetime. Evaporation is accelerated by tidal shocks, which implant additional ...
notes
... Astronomers are have found other stars with planets around them. They are able to tell that these stars have planets because of how the planet effects the star. Only large planets have been detected so far (half the mass of Jupiter). A small planet would be difficult to detect because it would have ...
... Astronomers are have found other stars with planets around them. They are able to tell that these stars have planets because of how the planet effects the star. Only large planets have been detected so far (half the mass of Jupiter). A small planet would be difficult to detect because it would have ...
February 13
... From Earth we can only measure a star’s parallax to about 100 pc. The distance to the center of the galaxy is 8 kpc or 80 times this distance. Why are parallax measurements so limited? What could you do to get parallax measurements for more distant stars? ...
... From Earth we can only measure a star’s parallax to about 100 pc. The distance to the center of the galaxy is 8 kpc or 80 times this distance. Why are parallax measurements so limited? What could you do to get parallax measurements for more distant stars? ...
Questions about the Sun:
... temperature. The classes are: O, B, A, F, G, K, and M; O stars are the hottest; M the coolest. The numbers are simply subdivisions of the major classes. The classes are oddly sequenced because they were assigned long ago before we understood their relationship to temperature. O and B stars are rare ...
... temperature. The classes are: O, B, A, F, G, K, and M; O stars are the hottest; M the coolest. The numbers are simply subdivisions of the major classes. The classes are oddly sequenced because they were assigned long ago before we understood their relationship to temperature. O and B stars are rare ...
Chapter 9 “The Family of Stars “
... determine the distance to stars that are currently too far to be measured using parallax from Earth. ...
... determine the distance to stars that are currently too far to be measured using parallax from Earth. ...
How do atoms interact with light?
... towards shorter wavelengths when the temperature increases. → Wien’s ...
... towards shorter wavelengths when the temperature increases. → Wien’s ...
Chapter 3 - BITS Pilani
... Assuming a spherical star of Radius R and M, the gravitational potential energy of the star, ...
... Assuming a spherical star of Radius R and M, the gravitational potential energy of the star, ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.