The correct answers are written in bold, italic and underlined. The
... 15. Tritium is a radioactive form of hydrogen in which the nucleus contains one proton and two neutrons. How much more massive is this nucleus than that of ordinary hydrogen? • The same mass because this nucleus is still hydrogen • Three times as massive • Twice as massive 16. Electron transitions b ...
... 15. Tritium is a radioactive form of hydrogen in which the nucleus contains one proton and two neutrons. How much more massive is this nucleus than that of ordinary hydrogen? • The same mass because this nucleus is still hydrogen • Three times as massive • Twice as massive 16. Electron transitions b ...
Ch 19 Directed Reading
... A TOOL FOR STUDYING STARS 10. What two things are graphed on the H-R diagram? a. a star’s temperature and brightness b. a star’s temperature and color c. a star’s temperature and age d. a star’s temperature and size Reading the H-R Diagram ...
... A TOOL FOR STUDYING STARS 10. What two things are graphed on the H-R diagram? a. a star’s temperature and brightness b. a star’s temperature and color c. a star’s temperature and age d. a star’s temperature and size Reading the H-R Diagram ...
Monday, October 27
... • Then do the following Gedankenexperiment: – In your mind, put the star from its actual position to a position 10 pc away – If a star is actually closer than 10pc, its absolute magnitude will be a bigger number, i.e. it is intrinsically dimmer than it appears – If a star is farther than 10pc, its a ...
... • Then do the following Gedankenexperiment: – In your mind, put the star from its actual position to a position 10 pc away – If a star is actually closer than 10pc, its absolute magnitude will be a bigger number, i.e. it is intrinsically dimmer than it appears – If a star is farther than 10pc, its a ...
Test 3
... 22) An object coming toward you exhibits a a) redshift b) blueshift 23) Suppose you have two stars tugging on each other with a force of 10 38 Newtons of force. Now you double the distance between them. What is the new force? a) ¼ × 1038 b) ½ × 1038 c) 2 × 1038 d) 4 × 1038 24) A planet moves faster ...
... 22) An object coming toward you exhibits a a) redshift b) blueshift 23) Suppose you have two stars tugging on each other with a force of 10 38 Newtons of force. Now you double the distance between them. What is the new force? a) ¼ × 1038 b) ½ × 1038 c) 2 × 1038 d) 4 × 1038 24) A planet moves faster ...
What is a Scientist? - Cockeysville Middle School
... by nuclear fusion. This is a process whereby hydrogen atoms are fused together to create helium atoms. In the process a tremendous amount of energy is given off in the form of electromagnetic waves and heat. There are billions of stars in a galaxy. When you look up into the night sky, most of the st ...
... by nuclear fusion. This is a process whereby hydrogen atoms are fused together to create helium atoms. In the process a tremendous amount of energy is given off in the form of electromagnetic waves and heat. There are billions of stars in a galaxy. When you look up into the night sky, most of the st ...
What`s Up - April 2016
... At about 40 times the diameter of the sun and 400 times as bright, Alphard is one of the ‘bright giants’ in our neighbourhood. But our ‘neighbourhood’ is rather large. Alphard is 11 million times as far away from us as our own sun – so it looks a lot dimmer to us! To the south of Sirius, and nearly ...
... At about 40 times the diameter of the sun and 400 times as bright, Alphard is one of the ‘bright giants’ in our neighbourhood. But our ‘neighbourhood’ is rather large. Alphard is 11 million times as far away from us as our own sun – so it looks a lot dimmer to us! To the south of Sirius, and nearly ...
PH109 Exploring the Uiverse, Test #4, Spring, 1999
... a) creations of science fiction writers b) the result of stars too massive for neutrons to support them c) condensed molecular clouds before star formation takes place d) small dark spot seen on the surface of the Sun 14. It is unlikely that astronauts will ever pass through black holes because a) t ...
... a) creations of science fiction writers b) the result of stars too massive for neutrons to support them c) condensed molecular clouds before star formation takes place d) small dark spot seen on the surface of the Sun 14. It is unlikely that astronauts will ever pass through black holes because a) t ...
Spectral Classification
... O stars are very hot and very luminous, being strongly violet in color; in fact, most of their output is in the ultraviolet range. These are the rarest of all main sequence stars, constituting as little as 1/32,000th of the total. O-stars shine with a power over a million times our Sun's output. E ...
... O stars are very hot and very luminous, being strongly violet in color; in fact, most of their output is in the ultraviolet range. These are the rarest of all main sequence stars, constituting as little as 1/32,000th of the total. O-stars shine with a power over a million times our Sun's output. E ...
Another Old Final
... (b) Estimate the distance to this supernova and the lookback time (how long ago we are observing it). (c) Type-Ia supernovae reach peak luminosities of 109 L . Estimate the peak apparent brightness of this supernova. Would it have been visible to the naked eye on a clear night? ...
... (b) Estimate the distance to this supernova and the lookback time (how long ago we are observing it). (c) Type-Ia supernovae reach peak luminosities of 109 L . Estimate the peak apparent brightness of this supernova. Would it have been visible to the naked eye on a clear night? ...
formation1
... • A region of the molecular cloud becomes dense. • This pocket of over density is much bigger than a single star. • This over dense region is not uniform, but has within it other, smaller regions of high density. • As the over density begins to be drawn together by gravity, it fragments into smaller ...
... • A region of the molecular cloud becomes dense. • This pocket of over density is much bigger than a single star. • This over dense region is not uniform, but has within it other, smaller regions of high density. • As the over density begins to be drawn together by gravity, it fragments into smaller ...
The Earth and BeyondGCSE
... Light from other galaxies has a longer _________ than expected. This shows that these galaxies are moving ____ from us very quickly. This effect is seen to a greater extent in galaxies that are _______ away from us. This indicates that the further away the galaxy is, the ______ it is moving. This ev ...
... Light from other galaxies has a longer _________ than expected. This shows that these galaxies are moving ____ from us very quickly. This effect is seen to a greater extent in galaxies that are _______ away from us. This indicates that the further away the galaxy is, the ______ it is moving. This ev ...
Review: How does a star`s mass determine its life story?
... that nothing can move faster than light When electron speeds in white dwarf approach speed of light, electron degeneracy pressure can no longer support it ...
... that nothing can move faster than light When electron speeds in white dwarf approach speed of light, electron degeneracy pressure can no longer support it ...
Cosmology 20B Homework 2 solutions
... absorption lines astronomers can figure out what types of atoms (and in what proportion) make up the gas. ...
... absorption lines astronomers can figure out what types of atoms (and in what proportion) make up the gas. ...
Stellar Forces
... electrons) is very inefficient as electrons collide often with other particles. However, ...
... electrons) is very inefficient as electrons collide often with other particles. However, ...
Problem Set # 8: The Last Problem Set Due Wednesday, December
... 1) [20 points] The dim little star Proxima Centauri, the Sun’s nearest neighbor among the stars, has a mass M = 0.12Msun , where Msun is the Sun’s mass. It has a luminosity L = 0.00014Lsun , where Lsun is the Sun’s luminosity. Like the Sun, Proxima Centauri is powered by the fusion of hydrogen into ...
... 1) [20 points] The dim little star Proxima Centauri, the Sun’s nearest neighbor among the stars, has a mass M = 0.12Msun , where Msun is the Sun’s mass. It has a luminosity L = 0.00014Lsun , where Lsun is the Sun’s luminosity. Like the Sun, Proxima Centauri is powered by the fusion of hydrogen into ...
Astron 104 Laboratory #7 Nuclear Fusion and Stars
... 11. Based on your previous answers, describe the forces two protons would feel as you bring them together from a large to a small separation distance. ...
... 11. Based on your previous answers, describe the forces two protons would feel as you bring them together from a large to a small separation distance. ...
AND STARS! The Sun s Source of Energy E= m c
... to expand. The energy would eventually be radiated off into space and the Sun would return to normal size. 4) The injected energy would heat the core, causing the Sun to expand. The Sun would find a new equilibrium with the gravitational pressure and end up being larger in size. ...
... to expand. The energy would eventually be radiated off into space and the Sun would return to normal size. 4) The injected energy would heat the core, causing the Sun to expand. The Sun would find a new equilibrium with the gravitational pressure and end up being larger in size. ...
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.