Answers for the HST Scavenger Hunt
... What is the difference between a galaxy and a nebula? A nebula is a cloud of gas and dust located between stars and/or surrounding stars. A galaxy is a collection of stars, gas, and dust bound together by gravity. How are galaxies classified? Galaxies are classified or grouped by their shape. ...
... What is the difference between a galaxy and a nebula? A nebula is a cloud of gas and dust located between stars and/or surrounding stars. A galaxy is a collection of stars, gas, and dust bound together by gravity. How are galaxies classified? Galaxies are classified or grouped by their shape. ...
Leo the Lion - Discovery Education
... You can look at a calendar to check when spring will come. However, 2,000 years ago, people looked at the sky to check if spring was coming. They looked to the stars. A star is a huge, hot, bright ball of gases. These people were looking for a particular group of stars. Stars can be grouped together ...
... You can look at a calendar to check when spring will come. However, 2,000 years ago, people looked at the sky to check if spring was coming. They looked to the stars. A star is a huge, hot, bright ball of gases. These people were looking for a particular group of stars. Stars can be grouped together ...
The Formation of Stars and Solar Systems
... Star formation is the process by which dense parts of molecular clouds collapse into a ball of plasma to form a star. The interstellar medium and giant molecular clouds act as precursors to the star formation process. The results include protostars and planets. Star formation begins in the interstel ...
... Star formation is the process by which dense parts of molecular clouds collapse into a ball of plasma to form a star. The interstellar medium and giant molecular clouds act as precursors to the star formation process. The results include protostars and planets. Star formation begins in the interstel ...
Ay123 Fall 2011 STELLAR STRUCTURE AND EVOLUTION Problem Set 4
... electrons are provided in cool stellar atmospheres presumably by metals, which have lower ionization thresholds than hydrogen or helium). b. Next, calculate the ratio n(H; n = 2)/n(H; n = 1) of the abundance of hydrogen atoms in the first excited state (n = 2) to the abundance in the ground state (n ...
... electrons are provided in cool stellar atmospheres presumably by metals, which have lower ionization thresholds than hydrogen or helium). b. Next, calculate the ratio n(H; n = 2)/n(H; n = 1) of the abundance of hydrogen atoms in the first excited state (n = 2) to the abundance in the ground state (n ...
Sporadic Mass Ejection in Red Supergiants
... Sharp-line observations in late-type giants and supergiants are probably the best indication that evolved stars are very likely slow rotators. Typical equatorial rotational velocities for type I K and M supergiants are generally believed to be less than 10 km s- 1 (Allen 1973). In contrast to 0 and ...
... Sharp-line observations in late-type giants and supergiants are probably the best indication that evolved stars are very likely slow rotators. Typical equatorial rotational velocities for type I K and M supergiants are generally believed to be less than 10 km s- 1 (Allen 1973). In contrast to 0 and ...
Celestial Motions - Stony Brook Astronomy
... • All other stars (and Sun, Moon, planets) rise in east and ...
... • All other stars (and Sun, Moon, planets) rise in east and ...
ASTR 105 Intro Astronomy: The Solar System
... causes the Sun to rise and set? A. The Earth’s orbit around the Sun B. Earth spinning on its axis C. Our solar system moving in the Milky Way ...
... causes the Sun to rise and set? A. The Earth’s orbit around the Sun B. Earth spinning on its axis C. Our solar system moving in the Milky Way ...
Circumstellar interaction in supernovae
... Few months to few years timescale Energy emitted 1051 ergs (1029 times more than an atmospheric nuclear explosion) Shines brighter than the host Galaxy As much energy in 1 month as sun in ~1 billion years In universe 8 supernova explosions every second Thermonuclear and gravitational collapse ...
... Few months to few years timescale Energy emitted 1051 ergs (1029 times more than an atmospheric nuclear explosion) Shines brighter than the host Galaxy As much energy in 1 month as sun in ~1 billion years In universe 8 supernova explosions every second Thermonuclear and gravitational collapse ...
Document
... white dwarf primary with a low mass (G-M) secondary, orbital periods of 67 min-2 days ...
... white dwarf primary with a low mass (G-M) secondary, orbital periods of 67 min-2 days ...
The First Stars in the Universe - Scientific American
... Cosmologists, however, can make deductions about the early universe based on the cosmic microwave background radiation, which was emitted about 400,000 years after the big bang. The uniformity of this radiation indicates that matter was distributed very smoothly at that time. Because there were no l ...
... Cosmologists, however, can make deductions about the early universe based on the cosmic microwave background radiation, which was emitted about 400,000 years after the big bang. The uniformity of this radiation indicates that matter was distributed very smoothly at that time. Because there were no l ...
Galaxies - science1d
... •The most distant galaxies are 15 million ly away •When light left them, the ...
... •The most distant galaxies are 15 million ly away •When light left them, the ...
The Rigel Star - Emmi
... Black Hole: an object whose gravity is so powerful that nothing, not even light, can escape. Neutron Star: the small, dense remains of a supergiant star after a supernova. Pulsar: a neutron star that spins very fast and releases radio waves. ...
... Black Hole: an object whose gravity is so powerful that nothing, not even light, can escape. Neutron Star: the small, dense remains of a supergiant star after a supernova. Pulsar: a neutron star that spins very fast and releases radio waves. ...
1/2 - Indico
... volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored thermal energy. White dwarfs are thought to be the final evolutionary state of all stars whose mass is not high enough to become a neutron star—over 97% of the stars in the Milky Way. After the hydrogen ...
... volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored thermal energy. White dwarfs are thought to be the final evolutionary state of all stars whose mass is not high enough to become a neutron star—over 97% of the stars in the Milky Way. After the hydrogen ...
powerpoint - High Energy Physics at Wayne State
... 50 LY across •H II region (red) high-energy UV hits interstellar gas •dark dust filaments – extinction due to debris from supernovae •blue reflection nebula February 14, 2006 ...
... 50 LY across •H II region (red) high-energy UV hits interstellar gas •dark dust filaments – extinction due to debris from supernovae •blue reflection nebula February 14, 2006 ...
Rethinking the Speed of Sound - University of Tennessee Physics
... divided by the square root of three. At high enough densities or temperatures, it always approaches this limit due to quantum chromodynamics (QCD)—the theory that describes how neutrons and protons interact. Their work, however, found this limit very likely does not hold. They used Monte Carlo simul ...
... divided by the square root of three. At high enough densities or temperatures, it always approaches this limit due to quantum chromodynamics (QCD)—the theory that describes how neutrons and protons interact. Their work, however, found this limit very likely does not hold. They used Monte Carlo simul ...
Hubble Does Double-Duty Science: Finding Planets and
... We have a very well-studied star at 1 AU, so why look any further? ...
... We have a very well-studied star at 1 AU, so why look any further? ...
Solutions to Homework #4, AST 203, Spring 2012
... General grading rules: One point off per question (e.g., 3a or 3b) for egregiously ignoring the admonition to set the context of your solution. Thus take the point off if relevant symbols aren’t defined, if important steps of explanation are missing, etc. If the answer is written down without *any* ...
... General grading rules: One point off per question (e.g., 3a or 3b) for egregiously ignoring the admonition to set the context of your solution. Thus take the point off if relevant symbols aren’t defined, if important steps of explanation are missing, etc. If the answer is written down without *any* ...
nuclear astrophysics applications for accelerators
... observation of 19 neutrinos from the SN1987a event – after sequential stages of fusion reactions, massive stars (M>8Msolar) develop an ‘onion skin’ structure with a core of iron and nickel. Further fusion is not energetically favourable, and the resulting loss of thermal pressure allows the core to ...
... observation of 19 neutrinos from the SN1987a event – after sequential stages of fusion reactions, massive stars (M>8Msolar) develop an ‘onion skin’ structure with a core of iron and nickel. Further fusion is not energetically favourable, and the resulting loss of thermal pressure allows the core to ...
Diffuse Ultraviolet Emission in Galaxies
... While we cannot yet prove that the widely distributed B stars are indeed as isolated as they appear, that interpretation is the simplest. Indeed, the evidence is consistent with a theory that star-forming regions are typically short-lived and suffer violent ends. Such appears to be the case in the O ...
... While we cannot yet prove that the widely distributed B stars are indeed as isolated as they appear, that interpretation is the simplest. Indeed, the evidence is consistent with a theory that star-forming regions are typically short-lived and suffer violent ends. Such appears to be the case in the O ...
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.