A not so massive cluster hosting a very massive star
... are ∼640 WR stars reported in the online “Galactic Wolf Rayet Catalogue”, but we expect over 1900 in our Galaxy (Rosslowe & Crowther 2015). It is also under debate the WR birth-place. We expect their formation in clustered environments, but it is unclear whether it happens in young clusters or assoc ...
... are ∼640 WR stars reported in the online “Galactic Wolf Rayet Catalogue”, but we expect over 1900 in our Galaxy (Rosslowe & Crowther 2015). It is also under debate the WR birth-place. We expect their formation in clustered environments, but it is unclear whether it happens in young clusters or assoc ...
Chapter 15. The Chandrasekhar Limit, Iron-56 and Core
... be composed of Carbon and Oxygen. Its dimensions will be roughly that of the Earth, but its mass will be typically about 0.5 solar masses or more. Its maximum mass is 1.4 solar masses, namely the Chandrasekhar limit. White dwarfs are supported by electron degeneracy pressure and therefore do not hav ...
... be composed of Carbon and Oxygen. Its dimensions will be roughly that of the Earth, but its mass will be typically about 0.5 solar masses or more. Its maximum mass is 1.4 solar masses, namely the Chandrasekhar limit. White dwarfs are supported by electron degeneracy pressure and therefore do not hav ...
The Effective Temperature and the Absolute Magnitude of the Stars
... According to definitions (6), the ratio (1 − β)/β is equal to the ratio between the pressure from the radiation and that from the hot gases, pr/pg. The numerical value of this ratio for a particular star, is used to get an idea on its degree of stability [2]. On the other hand, the product kcTc1 2 i ...
... According to definitions (6), the ratio (1 − β)/β is equal to the ratio between the pressure from the radiation and that from the hot gases, pr/pg. The numerical value of this ratio for a particular star, is used to get an idea on its degree of stability [2]. On the other hand, the product kcTc1 2 i ...
Lecture 9a: More on Star formation and evolution 10/22
... with modest telescope • usually dim red stars • dense with 100,000 stars in 50-300 LY region with less than LY separating stars • no heavy elements. Just Hydrogen and Helium • often outside plane of galaxy Understood as group of old stars formed in early history of the galaxy 3-12 billion years ...
... with modest telescope • usually dim red stars • dense with 100,000 stars in 50-300 LY region with less than LY separating stars • no heavy elements. Just Hydrogen and Helium • often outside plane of galaxy Understood as group of old stars formed in early history of the galaxy 3-12 billion years ...
Chapter 17 Measuring the Stars
... In order to measure stellar masses in a binary star, the period and semimajor axis of the orbit must be measured. Once this is done, Kepler’s third law gives the sum of the masses of the two stars. Then the relative speeds of the two stars can be measured using the Doppler effect; the speed will be ...
... In order to measure stellar masses in a binary star, the period and semimajor axis of the orbit must be measured. Once this is done, Kepler’s third law gives the sum of the masses of the two stars. Then the relative speeds of the two stars can be measured using the Doppler effect; the speed will be ...
Lecture101602
... luminosity = surface area x constant x T4 surface area = 4r2 (r = radius of star) luminosity = 4 r2 x constant x T4 we can solve for radius and calculate it ...
... luminosity = surface area x constant x T4 surface area = 4r2 (r = radius of star) luminosity = 4 r2 x constant x T4 we can solve for radius and calculate it ...
Lecture 8: The Stars - Department of Physics and Astronomy
... 0.1 times as much fuel, uses it 0.01 times as fast 100 billion years ~ 10 billion years x 0.1 / 0.01 ...
... 0.1 times as much fuel, uses it 0.01 times as fast 100 billion years ~ 10 billion years x 0.1 / 0.01 ...
Asteroseismology with the Whole Earth Telescope
... Magnetic field = 1300±300 G????? Differential Rotation – envelop rotating faster than core????? • Fontaine & Brassard • Temperature 22,900 K • Mass=0.625 Mo (C) 0.660 Mo (C/O)) • Log (Helium envelope mass) = -6.1 • Models depend on input physics – including convection parameters • Temperature fits d ...
... Magnetic field = 1300±300 G????? Differential Rotation – envelop rotating faster than core????? • Fontaine & Brassard • Temperature 22,900 K • Mass=0.625 Mo (C) 0.660 Mo (C/O)) • Log (Helium envelope mass) = -6.1 • Models depend on input physics – including convection parameters • Temperature fits d ...
Lecture 11: Stars, HR diagram.
... There is a very tight relationship between luminosity and temperature We see that the Sun is in this sequence... Then there is something in common between the Sun and the rest of the stars in the main sequence.... They are all burning H into He in their cores More luminous = hotter = more massive! L ...
... There is a very tight relationship between luminosity and temperature We see that the Sun is in this sequence... Then there is something in common between the Sun and the rest of the stars in the main sequence.... They are all burning H into He in their cores More luminous = hotter = more massive! L ...
Lecture 2 - SUNY Oswego
... and hence less pressure halting the expansion. Most stars are stable against departures from hydrostatic equilbrium because of this. In Cepheids and RR Lyraes, upon contraction, the extra energy flowing out is “held up” in the outer layers for a short while and released when the star is expanding ag ...
... and hence less pressure halting the expansion. Most stars are stable against departures from hydrostatic equilbrium because of this. In Cepheids and RR Lyraes, upon contraction, the extra energy flowing out is “held up” in the outer layers for a short while and released when the star is expanding ag ...
A Study of the Spectroscopic Variability of Select RV Tauri... Charles Kurgatt , Donald K. Walter , Steve Howell
... brightness. These changes in brightness may have many causes such as eclipses, stellar rotation, and pulsation. The two types studied here vary in brightness due to pulsations in the physical size of the stars. RV Tauri are distinguished by light curves that alternate over time between deep and shal ...
... brightness. These changes in brightness may have many causes such as eclipses, stellar rotation, and pulsation. The two types studied here vary in brightness due to pulsations in the physical size of the stars. RV Tauri are distinguished by light curves that alternate over time between deep and shal ...
Masses are much harder than distance, luminosity, or temperature
... D. They DO show a relationship or relation between them! ...
... D. They DO show a relationship or relation between them! ...
Ch. 19 (Starbirth)
... Planetary formation has begun, but the protostar is still not in equilibrium – all heating comes from the gravitational collapse. ...
... Planetary formation has begun, but the protostar is still not in equilibrium – all heating comes from the gravitational collapse. ...
Ch. 17 (RGs & WDs)
... the use of instructors in teaching their courses and assessing student learning. Dissemination or sale of any part of this work (including on the World Wide Web) will destroy the integrity of the work and is not permitted. The work and materials from it should never be made available to students exc ...
... the use of instructors in teaching their courses and assessing student learning. Dissemination or sale of any part of this work (including on the World Wide Web) will destroy the integrity of the work and is not permitted. The work and materials from it should never be made available to students exc ...
Self Assessment: Life Cycle of a Star
... a) the collapse of the iron core of an intermediate mass star b) the collapse of the iron core of a star with a mass greater than about six solar masses c) the collapse of a planetary nebula d) the collapse of the a star's core during the formation of a planetary nebula 4. The length of a star's l ...
... a) the collapse of the iron core of an intermediate mass star b) the collapse of the iron core of a star with a mass greater than about six solar masses c) the collapse of a planetary nebula d) the collapse of the a star's core during the formation of a planetary nebula 4. The length of a star's l ...
June 2017
... questions will be asked about it.) It was found that as the temperature of the emitter increased, so did the total amount of radiation emitted, but at the same time the value of λmax decreased. Graphs such as those shown in Fig. 1 are known as Planck curves and show both the rise in intensity and th ...
... questions will be asked about it.) It was found that as the temperature of the emitter increased, so did the total amount of radiation emitted, but at the same time the value of λmax decreased. Graphs such as those shown in Fig. 1 are known as Planck curves and show both the rise in intensity and th ...
Devil physics The baddest class on campus IB Physics
... forced into the same quantum state Pauli exclusion principle says they will acquire large kinetic energy which allows the star to resist gravitational pressure to collapse ...
... forced into the same quantum state Pauli exclusion principle says they will acquire large kinetic energy which allows the star to resist gravitational pressure to collapse ...
The HLCO Project - High Legh Community Observatory
... The largest known star by volume is KW Sagitari which is a whopping 1500 times the size of our Sun The heaviest known star is R136A1 in the Tarantula Nebula which started life as a lumbering 320 times heavier than the Sun The hottest known stars belongs to a special class known as a ‘Wolf-Rayet’ and ...
... The largest known star by volume is KW Sagitari which is a whopping 1500 times the size of our Sun The heaviest known star is R136A1 in the Tarantula Nebula which started life as a lumbering 320 times heavier than the Sun The hottest known stars belongs to a special class known as a ‘Wolf-Rayet’ and ...
Friday, April 26
... Super-Massive Stars end up as Black Holes • If the mass of the star is sufficiently large (M > 25 MSun), even the neutron pressure cannot halt the collapse – in fact, no known force can stop it! • The star collapses to a very small size, with ultrahigh density • Nearby gravity becomes so strong tha ...
... Super-Massive Stars end up as Black Holes • If the mass of the star is sufficiently large (M > 25 MSun), even the neutron pressure cannot halt the collapse – in fact, no known force can stop it! • The star collapses to a very small size, with ultrahigh density • Nearby gravity becomes so strong tha ...
Ch 20-21 Review
... Name ________________________________________ date ____________ Ch 20 and 21 REVIEW: Death of low and high mass stars 1) A star (no matter what its mass) spends most of its life: A) as a protostar. B) as a main sequence star. C) as a planetary nebula. D) as a red giant or supergiant. E) as a T Taur ...
... Name ________________________________________ date ____________ Ch 20 and 21 REVIEW: Death of low and high mass stars 1) A star (no matter what its mass) spends most of its life: A) as a protostar. B) as a main sequence star. C) as a planetary nebula. D) as a red giant or supergiant. E) as a T Taur ...
GLY 1001 Earth Science Name:__Answers
... Red giant – A large, cool star of high luminosity, a star occupying the upper-right portion of the Hertzsprung-Russell Diagram. Reflection nebula – A relatively dense dust cloud in interstellar space that is illuminated by starlight. Spiral galaxy – A flattened, rotating galaxy with pinwheel-like ar ...
... Red giant – A large, cool star of high luminosity, a star occupying the upper-right portion of the Hertzsprung-Russell Diagram. Reflection nebula – A relatively dense dust cloud in interstellar space that is illuminated by starlight. Spiral galaxy – A flattened, rotating galaxy with pinwheel-like ar ...
Lecture 7 Evolution of Massive Stars on the Main Sequence and
... becomes more precisely defined. Still one expects some overshoot mixing. A widely adopted prescription is to continue arbitrarily the convective mixing beyond its mathematical boundary by some fraction, a, of the pressure scale height. Maeder uses 20%. Stothers and Chin (ApJ, 381, L67), based on the ...
... becomes more precisely defined. Still one expects some overshoot mixing. A widely adopted prescription is to continue arbitrarily the convective mixing beyond its mathematical boundary by some fraction, a, of the pressure scale height. Maeder uses 20%. Stothers and Chin (ApJ, 381, L67), based on the ...
Nuclear Fusion – when two H atoms combine to form one atom thus
... Nebula – Stars are formed or “born” in a nebula. Massive cosmic cloud of matter from which stars are created. Light Year – distance light travels in one year. 186,000 miles/sec – speed of light Life Cycle of a Star Stars start off as a nebula until a nuclear explosion causes the star to shine. The n ...
... Nebula – Stars are formed or “born” in a nebula. Massive cosmic cloud of matter from which stars are created. Light Year – distance light travels in one year. 186,000 miles/sec – speed of light Life Cycle of a Star Stars start off as a nebula until a nuclear explosion causes the star to shine. The n ...