Scientific Justification
... As white dwarf stars cool over time, from hot planetary nebula nuclei down to the coolest temperatures possible given the finite age of the Galaxy, there are three narrow ranges of temperature where they can begin to pulsate. The interval where a given white dwarf will pulsate is determined by its s ...
... As white dwarf stars cool over time, from hot planetary nebula nuclei down to the coolest temperatures possible given the finite age of the Galaxy, there are three narrow ranges of temperature where they can begin to pulsate. The interval where a given white dwarf will pulsate is determined by its s ...
Hydrostatic Equilibrium of Hypothetical Quark Stars
... either by adding newly discovered elementary particles or by assuming some interactions between these elementary particles. A primitive and straightforward question then arises: What state occurs at the density higher than hyperon stars? No one can answer this question now, as our knowledge of stron ...
... either by adding newly discovered elementary particles or by assuming some interactions between these elementary particles. A primitive and straightforward question then arises: What state occurs at the density higher than hyperon stars? No one can answer this question now, as our knowledge of stron ...
Photometric Mass-to-Light Ratio In addition to a population`s total
... This is the Gunn-Gott criterion for sweeping of gas from spirals. When does this occur? Well, there are ∼ 2 × 1011 stars in the Milky Way, and the size of the Milky Way’s disk is R ∼ 20 kpc. If a typical Milky Way star is one solar mass, then the approximate stellar surface density is σ∗ = 2 × 1011 ...
... This is the Gunn-Gott criterion for sweeping of gas from spirals. When does this occur? Well, there are ∼ 2 × 1011 stars in the Milky Way, and the size of the Milky Way’s disk is R ∼ 20 kpc. If a typical Milky Way star is one solar mass, then the approximate stellar surface density is σ∗ = 2 × 1011 ...
Supernova
... • Sun-like stars (M< 9 Msolar) stop producing energy with Shell Helium Burning and leave behind a carbon core (White Dwarf). • Stars more massive continue to fuse heavier elements in their cores as they evolve. Carbon burning at 600 Million K Neon burning at 1.2 Billion K Oxygen Burning at 1.5 Billi ...
... • Sun-like stars (M< 9 Msolar) stop producing energy with Shell Helium Burning and leave behind a carbon core (White Dwarf). • Stars more massive continue to fuse heavier elements in their cores as they evolve. Carbon burning at 600 Million K Neon burning at 1.2 Billion K Oxygen Burning at 1.5 Billi ...
Goal: To understand how stars form.
... • It generates its energy from gravitational collapse and not from nuclear fusion like an adult star. • Eventually, the pressure and density at the core of this protostar increase. This increases the collisions of particles at its core. • This causes the core to heat up quickly. ...
... • It generates its energy from gravitational collapse and not from nuclear fusion like an adult star. • Eventually, the pressure and density at the core of this protostar increase. This increases the collisions of particles at its core. • This causes the core to heat up quickly. ...
X-ray studies of star and planet formation Eric Feigelson
... The expanding HII region around OB stars will shock and compress molecular cloud material, triggering a new generation of star formation. Few stellar samples are available to test the models (`collect-and-collapse’ and `radiative driven implosion’). Chandra is providing larger samples of triggered S ...
... The expanding HII region around OB stars will shock and compress molecular cloud material, triggering a new generation of star formation. Few stellar samples are available to test the models (`collect-and-collapse’ and `radiative driven implosion’). Chandra is providing larger samples of triggered S ...
chapter15SurveyStars..
... • What is a Hertzsprung-Russell diagram? – An H-R diagram plots stellar luminosity of stars versus surface temperature (or color or spectral type) ...
... • What is a Hertzsprung-Russell diagram? – An H-R diagram plots stellar luminosity of stars versus surface temperature (or color or spectral type) ...
Was our Solar System Born inside a Wolf
... from top left) 1.27, 2.49, 4.38 and 4.58 Myr. Note that the shell is unstable to several instabilities, related to both the hydrodynamics and the ionization front, which cause fragmentation and the formation of dense filaments and clumps [39, current work]. Injection of 26Al from the Wind to the Sol ...
... from top left) 1.27, 2.49, 4.38 and 4.58 Myr. Note that the shell is unstable to several instabilities, related to both the hydrodynamics and the ionization front, which cause fragmentation and the formation of dense filaments and clumps [39, current work]. Injection of 26Al from the Wind to the Sol ...
Lect15-3-23-11-stars..
... If we think about the glob of a larger gas cloud that collapses to form a single star, we can distinguish 4 stages of this contraction process under gravity, once this glob has contracted sufficiently to establish its distinct identity. We consider its collapse p beginning g g after it has become o ...
... If we think about the glob of a larger gas cloud that collapses to form a single star, we can distinguish 4 stages of this contraction process under gravity, once this glob has contracted sufficiently to establish its distinct identity. We consider its collapse p beginning g g after it has become o ...
Interstellar medium, birth and life of stars
... matter into space. G, K, and M stars at this stage are called T Tauri stars. A collection of a few hundred or a few thousand newborn stars formed in the plane of the Galaxy is called an open cluster. Stars escape from open clusters, most of which ...
... matter into space. G, K, and M stars at this stage are called T Tauri stars. A collection of a few hundred or a few thousand newborn stars formed in the plane of the Galaxy is called an open cluster. Stars escape from open clusters, most of which ...
Lecture 12: Age, Metalicity, and Observations Abundance
... Q(H o ) is the ionising photon luminosity constants are derived from evol. synthesis models (e.g., Kennicutt 1982) ...
... Q(H o ) is the ionising photon luminosity constants are derived from evol. synthesis models (e.g., Kennicutt 1982) ...
Lecture 30
... higher temperatures for nuclear burning of heavier elements: • Initially, burn hydrogen in the core • Once hydrogen is exhausted, too cool to burn helium • Core contracts, heats up • Helium burning stars • If star is massive enough, sequence repeats for carbon burning, then oxygen, silicon etc… Domi ...
... higher temperatures for nuclear burning of heavier elements: • Initially, burn hydrogen in the core • Once hydrogen is exhausted, too cool to burn helium • Core contracts, heats up • Helium burning stars • If star is massive enough, sequence repeats for carbon burning, then oxygen, silicon etc… Domi ...
ASTROPHYSICS UNIVERSE - Physics
... occupy the top right – these are red giants (large, cool stars). The bottom left is a region of small stars known as white dwarfs (small and hot) ...
... occupy the top right – these are red giants (large, cool stars). The bottom left is a region of small stars known as white dwarfs (small and hot) ...
Luminosity and magnitude
... • Using Wien’s Law: (peak emission) 1/temperature • And Stefan’s law: total energy emitted temperture4 Wien’s law: the hotter the object the bluer is its emission. Stefan’s law: energy emitted per unit area increases as the 4th power of the temperature….. Luminosity radius2 * temperture4 ...
... • Using Wien’s Law: (peak emission) 1/temperature • And Stefan’s law: total energy emitted temperture4 Wien’s law: the hotter the object the bluer is its emission. Stefan’s law: energy emitted per unit area increases as the 4th power of the temperature….. Luminosity radius2 * temperture4 ...
Astronomy 328 Midterm Exam - Department of Physics and Astronomy
... The Hlines (=656.3 nm) from two stars in a binary system are observed to have Doppler shifts of 0.022 and 0.044 nm, respectively. The period of the system is 20yr. The eclipse minima are flat bottomed and 200 days long. It takes 10 hours from first contact to reach the eclipse minimum. a) What ar ...
... The Hlines (=656.3 nm) from two stars in a binary system are observed to have Doppler shifts of 0.022 and 0.044 nm, respectively. The period of the system is 20yr. The eclipse minima are flat bottomed and 200 days long. It takes 10 hours from first contact to reach the eclipse minimum. a) What ar ...
CHP 11
... ____ 19. Protons and neutrons are held together in the nucleus by a. the weak force. b. the gravitational force. c. the electrostatic force. d. the strong force. e. the opacity. ____ 20. The carbon-nitrogen-oxygen cycle a. operates at a slightly lower temperature than the proton-proton chain. b. is ...
... ____ 19. Protons and neutrons are held together in the nucleus by a. the weak force. b. the gravitational force. c. the electrostatic force. d. the strong force. e. the opacity. ____ 20. The carbon-nitrogen-oxygen cycle a. operates at a slightly lower temperature than the proton-proton chain. b. is ...
printer-friendly sample test questions
... A. cooler, larger, redder, and brighter. B. cooler, smaller, bluer, and dimmer. C. hotter, smaller, bluer, and dimmer. D. hotter, larger, redder, and brighter. 7. What happens to cause a star to leave the main sequence? The gravitational pull inward becomes A. less than the outward pressure, so the ...
... A. cooler, larger, redder, and brighter. B. cooler, smaller, bluer, and dimmer. C. hotter, smaller, bluer, and dimmer. D. hotter, larger, redder, and brighter. 7. What happens to cause a star to leave the main sequence? The gravitational pull inward becomes A. less than the outward pressure, so the ...
Monday, Oct. 20
... A Red Giant with helium fusion When helium fusion starts generating energy in the core of a red giant, the core expands and hydrogen fusion in the shell around the core slows down. As a result, less total energy is being generated, and the envelope contracts and warms up some. But pretty soon all o ...
... A Red Giant with helium fusion When helium fusion starts generating energy in the core of a red giant, the core expands and hydrogen fusion in the shell around the core slows down. As a result, less total energy is being generated, and the envelope contracts and warms up some. But pretty soon all o ...
Star Formation
... • Gas in the cloud keeps falling onto the protostar. • The collapsing gas tends to start rotating around the protostar as it falls in forming a disk and a jet. • Eventually, the protostar develops a wind, like the solar wind but much stronger. This out flowing wind stops the in falling matter. • Th ...
... • Gas in the cloud keeps falling onto the protostar. • The collapsing gas tends to start rotating around the protostar as it falls in forming a disk and a jet. • Eventually, the protostar develops a wind, like the solar wind but much stronger. This out flowing wind stops the in falling matter. • Th ...
Diapositiva 1
... M > 1.6M or B-V < 0.25-0.3: Little or no stellar activity No evidence of significant angular momentum loss There is no trend on rotation with age (vsin i ~ cte) M < 1.6M or B-V > 0.25-0.3: Stellar activity does not depend on age or rotation Very slow angular momentum loss. Braking ti ...
... M > 1.6M or B-V < 0.25-0.3: Little or no stellar activity No evidence of significant angular momentum loss There is no trend on rotation with age (vsin i ~ cte) M < 1.6M or B-V > 0.25-0.3: Stellar activity does not depend on age or rotation Very slow angular momentum loss. Braking ti ...
Classifying the Stars
... Classifying the Stars Brightness Stars give off different amounts of light depending on their size and temperature. ...
... Classifying the Stars Brightness Stars give off different amounts of light depending on their size and temperature. ...
Astronomy 122 mid Term Exam
... 9. We observe a binary star system in which both stars have the same physical age. However, one of these stars is a 10 solar mass main sequence star while its companion is a 1 solar mass white dwarf. Explain what is odd about this system and provide a plausible explanation for this apparently parado ...
... 9. We observe a binary star system in which both stars have the same physical age. However, one of these stars is a 10 solar mass main sequence star while its companion is a 1 solar mass white dwarf. Explain what is odd about this system and provide a plausible explanation for this apparently parado ...
Star Birth - Sierra College Astronomy Home Page
... • A star must be massive enough to initiate fusion • Degeneracy pressure, which only depends on density and not temperature, prevents protostars less than 0.08 MSun (which is 80 times more massive than Jupiter), from reaching the fusion temperature • Brown dwarfs are “failed stars” with masses betwe ...
... • A star must be massive enough to initiate fusion • Degeneracy pressure, which only depends on density and not temperature, prevents protostars less than 0.08 MSun (which is 80 times more massive than Jupiter), from reaching the fusion temperature • Brown dwarfs are “failed stars” with masses betwe ...