EX - Uplift North Hills Prep
... EX: Suppose I observe with my telescope two stars, C and D, that form a binary star pair. ▪ Star C has a spectral peak at 350 nm - deep violet ▪ Star D has a spectral peak at 700 nm - deep red What are the temperatures of the stars? ...
... EX: Suppose I observe with my telescope two stars, C and D, that form a binary star pair. ▪ Star C has a spectral peak at 350 nm - deep violet ▪ Star D has a spectral peak at 700 nm - deep red What are the temperatures of the stars? ...
X-ray astronomy - University of Warwick
... – Mass loss ~ 10-6 MSUN yr-1 (The Sun loses 10-14 MSUN yr-1) – wind velocity ~ 3000 km s-1 (solar velocity~ 300kms-1) ...
... – Mass loss ~ 10-6 MSUN yr-1 (The Sun loses 10-14 MSUN yr-1) – wind velocity ~ 3000 km s-1 (solar velocity~ 300kms-1) ...
ASTR-1020: Astronomy II Course Lecture Notes - Faculty
... which in turn, causes a rapid increase in the light output of the system. Such a binary is called a cataclysmic variable and can go through numerous (though not necessarily periodic) episodes of rapid brightenings. The most energetic of the cataclysmic variables are called dwarf novae. Such systems ...
... which in turn, causes a rapid increase in the light output of the system. Such a binary is called a cataclysmic variable and can go through numerous (though not necessarily periodic) episodes of rapid brightenings. The most energetic of the cataclysmic variables are called dwarf novae. Such systems ...
White Dwarf Stars After nuclear burning ceases, a post
... • Many intermediate temperature white dwarf atmospheres do convect. Thus, simple radiative energy transport is not applicable to all white dwarfs. This changes the cooling curve somewhat, and can change the surface abundances. • It is an observed fact that the overwhelming majority of white dwarfs h ...
... • Many intermediate temperature white dwarf atmospheres do convect. Thus, simple radiative energy transport is not applicable to all white dwarfs. This changes the cooling curve somewhat, and can change the surface abundances. • It is an observed fact that the overwhelming majority of white dwarfs h ...
– 1 – 1. A Gas
... is a statement of conservation of energy. One then considers an adiabatic change, where “adiabatic” means constant entropy, no net heat flow, dQ = 0, so P dV = −dU. Another derivation of the eqtn of hydrostatic equilibrium proceeds from there (see KWT). Rotating stars are a special case. We can assu ...
... is a statement of conservation of energy. One then considers an adiabatic change, where “adiabatic” means constant entropy, no net heat flow, dQ = 0, so P dV = −dU. Another derivation of the eqtn of hydrostatic equilibrium proceeds from there (see KWT). Rotating stars are a special case. We can assu ...
kaekae14 dae dae15 lifecycleofastar
... Black holes are objects so dense that not even light can escape their gravity, and ...
... Black holes are objects so dense that not even light can escape their gravity, and ...
matthewchristianstarprodject
... Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and roughly the same mass as protons. Neutron stars are very hot and are supported against further collapse because of the Pauli exclusion principle. This principle states that no two n ...
... Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and roughly the same mass as protons. Neutron stars are very hot and are supported against further collapse because of the Pauli exclusion principle. This principle states that no two n ...
Highligh in Physics 2005
... $Institute of Astronomy, Cambridge, UK The paradigm of accretion has had a major impact on a variety of phenomena in astrophysics; in particular, it has often been applied to the context of proto-stellar disks. We have studied the role of the disk self-gravity on the properties of accretion disks an ...
... $Institute of Astronomy, Cambridge, UK The paradigm of accretion has had a major impact on a variety of phenomena in astrophysics; in particular, it has often been applied to the context of proto-stellar disks. We have studied the role of the disk self-gravity on the properties of accretion disks an ...
Discovery of 7-13 HZ quasi-periodic oscillations in the new X
... correlation between X-ray count rate and the QPO parameters. In the X-ray colorcolor diagram a two-branched structure was traced out. The QPO parameters are well correlated with the position of the source on these branches. During earlier observations on 1998 April 27, 28 and 29 the count rates were ...
... correlation between X-ray count rate and the QPO parameters. In the X-ray colorcolor diagram a two-branched structure was traced out. The QPO parameters are well correlated with the position of the source on these branches. During earlier observations on 1998 April 27, 28 and 29 the count rates were ...
From Black Holes to Cosmology : The Universe in the
... 2.1. From gravitational collapse to gamma-ray bursts Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They can last from ten milliseconds to several minutes, and their light curves vary considerably from one ...
... 2.1. From gravitational collapse to gamma-ray bursts Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They can last from ten milliseconds to several minutes, and their light curves vary considerably from one ...
Final Review Sheet
... Typical mass 1.4 Msun (neutrinos carry away significant mass energy in the explosion). Typical radius 10 km. Central density over 10**15 g/cm**3. Like white dwarfs have a maximum mass, but the value is uncertain. Probably near 2 Msun. If the supernova leaves behind a remnant larger than this it will ...
... Typical mass 1.4 Msun (neutrinos carry away significant mass energy in the explosion). Typical radius 10 km. Central density over 10**15 g/cm**3. Like white dwarfs have a maximum mass, but the value is uncertain. Probably near 2 Msun. If the supernova leaves behind a remnant larger than this it will ...
m 1
... Brightness - depends on T, R, d Magnitudes (backwards, logarithmic)= -2.5 log(flux) + C or m2 - m1 = -2.5 log (f2/f1) • m (apparent mag - as seen from earth - includes d) • M (absolute mag - object at 10 pc - eliminates d) • m-M = -5 + 5 log d (distance modulus) • MBOL (bolometric mag - over all ) ...
... Brightness - depends on T, R, d Magnitudes (backwards, logarithmic)= -2.5 log(flux) + C or m2 - m1 = -2.5 log (f2/f1) • m (apparent mag - as seen from earth - includes d) • M (absolute mag - object at 10 pc - eliminates d) • m-M = -5 + 5 log d (distance modulus) • MBOL (bolometric mag - over all ) ...
Stellar Lifetime - Madison Public Schools
... • Nuclear reactions occur within the core of a star at tremendous temperatures and pressures. Explain what occurs in the core on an atomic level. What happens to an atom made up of many protons, neutrons, and electrons? What causes the particles to fuse together? How is energy released and where doe ...
... • Nuclear reactions occur within the core of a star at tremendous temperatures and pressures. Explain what occurs in the core on an atomic level. What happens to an atom made up of many protons, neutrons, and electrons? What causes the particles to fuse together? How is energy released and where doe ...
Document
... Central dust cloud has a form of a prolate ellipsoid with the axis ratio about 2.5. The ellipsoid lays in the plane of equatorial ring and expands with the velocity of ~3000 km/s. The dust is heated by X-rays from the ring and by the decay of Ti44 and radiates in far infrared. ...
... Central dust cloud has a form of a prolate ellipsoid with the axis ratio about 2.5. The ellipsoid lays in the plane of equatorial ring and expands with the velocity of ~3000 km/s. The dust is heated by X-rays from the ring and by the decay of Ti44 and radiates in far infrared. ...
1. Horizon regularity and surface gravity Consider a static
... Follow John Michell and Simon de Laplace and compute, using Newtonian mechanics, the radius rM L at which the escape velocity of a test particle in this field reaches the speed of light. This is the radius of a Newtonian ‘dark star’ in higher dimensions. Check that this is exactly the same, in any D ...
... Follow John Michell and Simon de Laplace and compute, using Newtonian mechanics, the radius rM L at which the escape velocity of a test particle in this field reaches the speed of light. This is the radius of a Newtonian ‘dark star’ in higher dimensions. Check that this is exactly the same, in any D ...
What is a Star - Optics Institute of Southern California
... The Main Sequence The properties of a main sequence star can be understood by considering the various physical processes acting in the interior. First is the hydrostatic balance, also called hydrostatic equilibrium. This determines the density structure of the star as the internal pressure gradient ...
... The Main Sequence The properties of a main sequence star can be understood by considering the various physical processes acting in the interior. First is the hydrostatic balance, also called hydrostatic equilibrium. This determines the density structure of the star as the internal pressure gradient ...
Disk evolution
... • gas accretes along magnetic field lines (free-fall, accretion shock on surface) • magnetic field allows star to exert a non-zero torque on disk inner edge (in principle, star may spin down) • innermost disk is missing ...
... • gas accretes along magnetic field lines (free-fall, accretion shock on surface) • magnetic field allows star to exert a non-zero torque on disk inner edge (in principle, star may spin down) • innermost disk is missing ...
Galactic Star Formation Science with Integral Field
... • IRAS 04158+2805 = young proto-object in the Taurus SFR (d~140pc) • Seen in the optical largely in scattered light, with a ‘bipolar’ nebula structure typical of opaque disk material along the mid-plane (Glauser et al. ’08), interpreted as a source with a disk inclined by ~63o • YOUNG! (<~1Myo!) w./ ...
... • IRAS 04158+2805 = young proto-object in the Taurus SFR (d~140pc) • Seen in the optical largely in scattered light, with a ‘bipolar’ nebula structure typical of opaque disk material along the mid-plane (Glauser et al. ’08), interpreted as a source with a disk inclined by ~63o • YOUNG! (<~1Myo!) w./ ...
Signatures of the first stars in the 21cm Emission and Absorption
... • Lyα photons couple the spin and kinetic temperatures out to a radius much larger than the HII region. • X-rays from the stellar photosphere heat the medium. • X-ray ionizations also produce injected Lyα photons, which turn out to dominate for the surface temperatures of metal-free stars. These yie ...
... • Lyα photons couple the spin and kinetic temperatures out to a radius much larger than the HII region. • X-rays from the stellar photosphere heat the medium. • X-ray ionizations also produce injected Lyα photons, which turn out to dominate for the surface temperatures of metal-free stars. These yie ...
Cygnus X-1
Cygnus X-1 (abbreviated Cyg X-1) is a well-known galactic X-ray source, thought to be a black hole, in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 6977229999999999999♠2.3×10−23 Wm−2 Hz−1 (7003230000000000000♠2.3×103 Jansky). Cygnus X-1 was the first X-ray source widely accepted to be a black hole and it remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any known kind of normal star, or other likely object besides a black hole. If so, the radius of its event horizon is about 7004440000000000000♠44 km.Cygnus X-1 belongs to a high-mass X-ray binary system about 7019574266339685654♠6070 ly from the Sun that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicular to the disk, are carrying part of the energy of the infalling material away into interstellar space.This system may belong to a stellar association called Cygnus OB3, which would mean that Cygnus X-1 is about five million years old and formed from a progenitor star that had more than 7001400000000000000♠40 solar masses. The majority of the star's mass was shed, most likely as a stellar wind. If this star had then exploded as a supernova, the resulting force would most likely have ejected the remnant from the system. Hence the star may have instead collapsed directly into a black hole.Cygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.