Supernovae
... • Probably type II SN because originator was massive B star (20 M) • Neutrinos are rarely absorbed so energy changed little over many x 10 9 years (except for loss due to expansion of Universe)… thus they are very difficult to detect. • However density of collapsing SN core is so high that it imped ...
... • Probably type II SN because originator was massive B star (20 M) • Neutrinos are rarely absorbed so energy changed little over many x 10 9 years (except for loss due to expansion of Universe)… thus they are very difficult to detect. • However density of collapsing SN core is so high that it imped ...
Life Cycle of Stars Lab
... characteristics did you use, and what clues from one picture helped you with another? Describe your method in enough detail that other students could follow it and get the same answers you did. ...
... characteristics did you use, and what clues from one picture helped you with another? Describe your method in enough detail that other students could follow it and get the same answers you did. ...
Massive star formation in 100000 years from turbulent and
... rate of the star; the value of the former quantity is currently uncertain by many orders of magnitude1,2,3,4,5,6 , leading to other astrophysical questions. For example, the variation of t∗f with stellar mass dictates whether massive stars can form simultaneously with low-mass stars in clusters. Her ...
... rate of the star; the value of the former quantity is currently uncertain by many orders of magnitude1,2,3,4,5,6 , leading to other astrophysical questions. For example, the variation of t∗f with stellar mass dictates whether massive stars can form simultaneously with low-mass stars in clusters. Her ...
Variable Star Observation
... two classes of stars within the extrinsic group. • A binary star is a stellar system consisting of two stars orbiting around their center of mass. ...
... two classes of stars within the extrinsic group. • A binary star is a stellar system consisting of two stars orbiting around their center of mass. ...
Mass and Age determination for low
... With this work we pretend to test MESA for the determination of mass and age for PMS stars. ...
... With this work we pretend to test MESA for the determination of mass and age for PMS stars. ...
Globular Clusters - University of Dayton
... Turn Off - As the hydrogen fuel in a star's core runs out the core begins to collapse due to gravity and the star moves away from the main sequence. At the turn off nearly all the central fuel is gone. Red Giant Branch - When the central fuel is gone, hydrogen starts to burn in an envelope around a ...
... Turn Off - As the hydrogen fuel in a star's core runs out the core begins to collapse due to gravity and the star moves away from the main sequence. At the turn off nearly all the central fuel is gone. Red Giant Branch - When the central fuel is gone, hydrogen starts to burn in an envelope around a ...
Death - Wayne State University Physics and Astronomy
... • They are now known to be caused by old, dead stars • The spectra of a nova shows blue-shifted absorption lines showing that a hot dense gas is expanding towards us at a few thousands of kilometers per second • The continuum is from the hot dense gas and the absorption lines are from the lowerdensi ...
... • They are now known to be caused by old, dead stars • The spectra of a nova shows blue-shifted absorption lines showing that a hot dense gas is expanding towards us at a few thousands of kilometers per second • The continuum is from the hot dense gas and the absorption lines are from the lowerdensi ...
ASTR2050 Introduction to Astronomy and Astrophysics Studio lab April 1, 2005
... Studio lab April 1, 2005 Worksheet ...
... Studio lab April 1, 2005 Worksheet ...
1_Introduction
... How do we know? Lifespan is longest for the thrifty “subcompact” stars barely massive enough for fusion. Eventually, though, they “run out of gas”. ...
... How do we know? Lifespan is longest for the thrifty “subcompact” stars barely massive enough for fusion. Eventually, though, they “run out of gas”. ...
From galaxies to stars
... collapses, it tends to flatten into a disk. The central region collapses fastest, and begins to heat up: the cloud is collapsing from the inside. As the density increases, the cloud becomes opaque, trapping the heat within the cloud. This then causes both the temperature and pressure to rise rapidly ...
... collapses, it tends to flatten into a disk. The central region collapses fastest, and begins to heat up: the cloud is collapsing from the inside. As the density increases, the cloud becomes opaque, trapping the heat within the cloud. This then causes both the temperature and pressure to rise rapidly ...
Astrometry of Binary Stars: What Are We Waiting For?
... Future projects such as SIM, GAIA: a very important development for binary star research. ...
... Future projects such as SIM, GAIA: a very important development for binary star research. ...
A minimum column density of 1gcm(
... For the models shown in Fig. 2 a cloud reaches its equilibrium light-to-mass ratio within about 3tff after star formation begins, and because SFRff is less than about 0.05, at most ,15% of the mass will have gone into low-mass stars at this point. If star formation accelerates in time, as predicted ...
... For the models shown in Fig. 2 a cloud reaches its equilibrium light-to-mass ratio within about 3tff after star formation begins, and because SFRff is less than about 0.05, at most ,15% of the mass will have gone into low-mass stars at this point. If star formation accelerates in time, as predicted ...
14_MilkyWay_advanced_2014may
... • Objects further away look fainter • If the star is too far away, it will be fainter than our limiting magnitude and we won’t see it. • Assume at 10 parsecs an average star has (absolute) magnitude of M=+2.5 • Every factor of 10 in distance it gets 5 magnitude fainter ...
... • Objects further away look fainter • If the star is too far away, it will be fainter than our limiting magnitude and we won’t see it. • Assume at 10 parsecs an average star has (absolute) magnitude of M=+2.5 • Every factor of 10 in distance it gets 5 magnitude fainter ...
transcript
... 03:33 Ones we will call terrestrial, which are rocky planets like our earth and the others we will call gases, like Jupiter and Saturn because they are mostly made of gas. So rocky planets reside closer to the star [our sun] so we have four planets residing close to our sun because rocky material ca ...
... 03:33 Ones we will call terrestrial, which are rocky planets like our earth and the others we will call gases, like Jupiter and Saturn because they are mostly made of gas. So rocky planets reside closer to the star [our sun] so we have four planets residing close to our sun because rocky material ca ...
N-Body Simulations of Star Clusters with IMBH
... Evolution of Star Clusters with Black Holes Our simulations have shown that star clusters with high enough densities can form black holes through run-away merging of stars. In addition, the simulations done so far have shown that a black hole in M15 is not necessary to explain the observations, but ...
... Evolution of Star Clusters with Black Holes Our simulations have shown that star clusters with high enough densities can form black holes through run-away merging of stars. In addition, the simulations done so far have shown that a black hole in M15 is not necessary to explain the observations, but ...
From Rubber Bands to Big Bangs
... The Universe has been expanding for almost 14 billion years from a smaller, hotter, denser form to its present cooler, larger, and less dense form. You might ask, “What is expanding, and how do we know that?” The Cosmic Microwave Background Radiation (CMB) is scientific evidence that shows space its ...
... The Universe has been expanding for almost 14 billion years from a smaller, hotter, denser form to its present cooler, larger, and less dense form. You might ask, “What is expanding, and how do we know that?” The Cosmic Microwave Background Radiation (CMB) is scientific evidence that shows space its ...
ASTRONOMY - Frost Middle School
... HOW OLD IS THE UNIVERSE? • Once the star’s atmosphere is lost, all that is left is the carbon-oxygen core- a white dwarf-which is tiny, hot, and dense • The oldest white dwarfs are 12 billion to 13 billion years old • Because it took about 1 billion years after the big bang for the first white • dw ...
... HOW OLD IS THE UNIVERSE? • Once the star’s atmosphere is lost, all that is left is the carbon-oxygen core- a white dwarf-which is tiny, hot, and dense • The oldest white dwarfs are 12 billion to 13 billion years old • Because it took about 1 billion years after the big bang for the first white • dw ...
From Rubber Bands to Big Bangs The Universe has been
... The Universe has been expanding for almost 14 billion years from a smaller, hotter, denser form to its present cooler, larger, and less dense form. You might ask, “What is expanding, and how do we know that?” The Cosmic Microwave Background Radiation (CMB) is scientific evidence that shows space its ...
... The Universe has been expanding for almost 14 billion years from a smaller, hotter, denser form to its present cooler, larger, and less dense form. You might ask, “What is expanding, and how do we know that?” The Cosmic Microwave Background Radiation (CMB) is scientific evidence that shows space its ...
ASTR 1020 General Astronomy: Stars and Galaxies REVIEW
... No White Dwarf Can have more than 1.4M~ Otherwise it will groan and collapse under its own weight. We’ll come back to this later. ...
... No White Dwarf Can have more than 1.4M~ Otherwise it will groan and collapse under its own weight. We’ll come back to this later. ...
Properties of Stars Measuring Stars Apparent Magnitude, m Range
... Star seems to move in an ellipse ...
... Star seems to move in an ellipse ...
Numerical Evolu4on of Soliton Stars
... Dark MaPer and Dark Energy • Hubble Telescope observa.ons 1998 of distant supernovae showed that the expansion of the universe was accelera.ng rather than slowing down. • Postulated dark energy (non zero cosmological constant working like a repulsive force). • Present es.mates are abou ...
... Dark MaPer and Dark Energy • Hubble Telescope observa.ons 1998 of distant supernovae showed that the expansion of the universe was accelera.ng rather than slowing down. • Postulated dark energy (non zero cosmological constant working like a repulsive force). • Present es.mates are abou ...
Overview Evolution of massive stars Evolution of massive stars
... shock. This is poorly understood and an active area of research. Eventually shock overcomes material falling inward: explosion – Supernova! ...
... shock. This is poorly understood and an active area of research. Eventually shock overcomes material falling inward: explosion – Supernova! ...
Ay123 Fall 2011 STELLAR STRUCTURE AND EVOLUTION Problem Set 4
... the electron pressure, Pe = ne kT (where ne is the free-electron number density; these free 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 ...
... the electron pressure, Pe = ne kT (where ne is the free-electron number density; these free 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 ...
Main sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or ""dwarf"" stars.After a star has formed, it generates thermal energy in the dense core region through the nuclear fusion of hydrogen atoms into helium. During this stage of the star's lifetime, it is located along the main sequence at a position determined primarily by its mass, but also based upon its chemical composition and other factors. All main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward pressure of gravitational collapse from the overlying layers. The strong dependence of the rate of energy generation in the core on the temperature and pressure helps to sustain this balance. Energy generated at the core makes its way to the surface and is radiated away at the photosphere. The energy is carried by either radiation or convection, with the latter occurring in regions with steeper temperature gradients, higher opacity or both.The main sequence is sometimes divided into upper and lower parts, based on the dominant process that a star uses to generate energy. Stars below about 1.5 times the mass of the Sun (or 1.5 solar masses (M☉)) primarily fuse hydrogen atoms together in a series of stages to form helium, a sequence called the proton–proton chain. Above this mass, in the upper main sequence, the nuclear fusion process mainly uses atoms of carbon, nitrogen and oxygen as intermediaries in the CNO cycle that produces helium from hydrogen atoms. Main-sequence stars with more than two solar masses undergo convection in their core regions, which acts to stir up the newly created helium and maintain the proportion of fuel needed for fusion to occur. Below this mass, stars have cores that are entirely radiative with convective zones near the surface. With decreasing stellar mass, the proportion of the star forming a convective envelope steadily increases, whereas main-sequence stars below 0.4 M☉ undergo convection throughout their mass. When core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.In general, the more massive a star is, the shorter its lifespan on the main sequence. After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram. The behavior of a star now depends on its mass, with stars below 0.23 M☉ becoming white dwarfs directly, whereas stars with up to ten solar masses pass through a red giant stage. More massive stars can explode as a supernova, or collapse directly into a black hole.