Black Holes
... Chandra's improved sensitivity is making possible more detailed studies of black holes, supernovae, and dark matter. ...
... Chandra's improved sensitivity is making possible more detailed studies of black holes, supernovae, and dark matter. ...
test - Scioly.org
... *All of the following FACTS are wrong! Your duty is to CORRECT them by replacing a since word (or number) in each sentence. Value 1 point each, but only if you can find the exact incorrect word (or letter, or number) and suggest a logical replacement which turns the wrong fact into a right one. 1) T ...
... *All of the following FACTS are wrong! Your duty is to CORRECT them by replacing a since word (or number) in each sentence. Value 1 point each, but only if you can find the exact incorrect word (or letter, or number) and suggest a logical replacement which turns the wrong fact into a right one. 1) T ...
Astronomy 82 - Problem Set #1
... In this case, the quantity we are given is an angular radius of 3 arcminutes and the rate is the increase in angular size: 0.21” per year. Set it up the same as the bathtub problem: quantity 3arcmin 60arcsec t= ...
... In this case, the quantity we are given is an angular radius of 3 arcminutes and the rate is the increase in angular size: 0.21” per year. Set it up the same as the bathtub problem: quantity 3arcmin 60arcsec t= ...
Thought Question
... The parallax of Proxima Centauri (the closest star to the Sun) is roughly twice that of Sirius (the brightest star in the Earth’s night sky). This means that Sirius is: A. Twice as close as Proxima Centauri B. Almost the same distance but moving faster C. Twice as far as Proxima Centauri D. None of ...
... The parallax of Proxima Centauri (the closest star to the Sun) is roughly twice that of Sirius (the brightest star in the Earth’s night sky). This means that Sirius is: A. Twice as close as Proxima Centauri B. Almost the same distance but moving faster C. Twice as far as Proxima Centauri D. None of ...
Black holes
... The asteroid belt is divided into an inner belt and an outer belt. The inner belt, which is made up of asteroids that are within 250 million miles (402 million km) of the sun, contains asteroids that are made of metals. The outer belt, which includes asteroids 250 million miles (402 million km) beyo ...
... The asteroid belt is divided into an inner belt and an outer belt. The inner belt, which is made up of asteroids that are within 250 million miles (402 million km) of the sun, contains asteroids that are made of metals. The outer belt, which includes asteroids 250 million miles (402 million km) beyo ...
KERR (SPINNING) BLACK HOLES Generalized BH solution that includes spin Roy Kerr
... and a rotating black hole. The inner black region represents the event horizon, The surroundings blue and white rings represent hot gas that is whirling around The black hole on its way to oblivion. The green grid depicts space-time coordinates. Note how the spinning black hole distorts the space ti ...
... and a rotating black hole. The inner black region represents the event horizon, The surroundings blue and white rings represent hot gas that is whirling around The black hole on its way to oblivion. The green grid depicts space-time coordinates. Note how the spinning black hole distorts the space ti ...
ppt
... How do the photons ever get out? Temperature of star decreases outward from center. This causes the radiation pressure to decrease outwards as well ...
... How do the photons ever get out? Temperature of star decreases outward from center. This causes the radiation pressure to decrease outwards as well ...
mass of star
... stars produce huge amounts of these. Such short-lived stars spend all their lives in the stellar nursery of their birth, so emission nebulae mark sites of ongoing star formation. Many stars of lower mass are forming too, but make few UV photons. Why "H II Region? H I: Hydrogen atom H II: Ionized Hyd ...
... stars produce huge amounts of these. Such short-lived stars spend all their lives in the stellar nursery of their birth, so emission nebulae mark sites of ongoing star formation. Many stars of lower mass are forming too, but make few UV photons. Why "H II Region? H I: Hydrogen atom H II: Ionized Hyd ...
Phys 100 – Astronomy (Dr. Ilias Fernini) Review Questions for
... a. searching for single stars that emit large amounts of x-rays. * b. finding x-ray binaries where the compact companion has a mass in excess of 3 M . c. searching for large spherical regions from which no light is detected. d. looking for pulsars with periods less than one millisecond. 64. The mat ...
... a. searching for single stars that emit large amounts of x-rays. * b. finding x-ray binaries where the compact companion has a mass in excess of 3 M . c. searching for large spherical regions from which no light is detected. d. looking for pulsars with periods less than one millisecond. 64. The mat ...
Astrosat (India) - X-ray Astronomy Group at ISAS
... the acceleration processes and origin of cosmic rays in the case of SNRs. ...
... the acceleration processes and origin of cosmic rays in the case of SNRs. ...
PHYS2160 Notes 4
... stars (Hartmann 1904) – that is stars where the velocities of the two stellar componentises varied, but there was a third component that did not move.. Total dust mass is small, but its impact on astronomy is significant – it stops us seeing the Galactic centre in visible light, or seeing the dense ...
... stars (Hartmann 1904) – that is stars where the velocities of the two stellar componentises varied, but there was a third component that did not move.. Total dust mass is small, but its impact on astronomy is significant – it stops us seeing the Galactic centre in visible light, or seeing the dense ...
Teresa Ashcraft
... evolutionary trend of the IRX and SSFR - IRX found from gas surface density and metallicity - metallicity grows with time - SFR determined by exponentially falling gas density The rise in the SFR density to z=1 is due to Galaxies in the mass range of the turnoff mass (10.5-11.5) Use IRX as a too ...
... evolutionary trend of the IRX and SSFR - IRX found from gas surface density and metallicity - metallicity grows with time - SFR determined by exponentially falling gas density The rise in the SFR density to z=1 is due to Galaxies in the mass range of the turnoff mass (10.5-11.5) Use IRX as a too ...
Properties of Stars
... Starlight can be analyzed using a spectroscope to infer which gases make up the star. ...
... Starlight can be analyzed using a spectroscope to infer which gases make up the star. ...
Stability of hot neutron stars
... slowingdown of its rotation after the freezing of thermonuclear equilibrium. The change of nuclear compositions, which takes place during the compression, has been investigated. If the initial species of nuclei is 56Fe, the charge and the mass number of nuclei decrease as a result of repeated electr ...
... slowingdown of its rotation after the freezing of thermonuclear equilibrium. The change of nuclear compositions, which takes place during the compression, has been investigated. If the initial species of nuclei is 56Fe, the charge and the mass number of nuclei decrease as a result of repeated electr ...
Exercise 4
... 1. (a) The star is nearly a blackbody, the spectrum of a star can be approximated as a blackbody radiation curve. On the curve, there is a peak which shifts to shorter wavelength when the temperature of the blackbody increases. From the position of the peak, astronomers can deduce the surface temper ...
... 1. (a) The star is nearly a blackbody, the spectrum of a star can be approximated as a blackbody radiation curve. On the curve, there is a peak which shifts to shorter wavelength when the temperature of the blackbody increases. From the position of the peak, astronomers can deduce the surface temper ...
Stars
... amount of energy, but there are billions of reactions per second. Each second, the Sun produces 4 × 1026 joules of energy. It would take 2,000 million nuclear power plants a whole year to produce the same amount of energy on Earth. In the Sun, and in most stars, hydrogen atoms fuse together to form ...
... amount of energy, but there are billions of reactions per second. Each second, the Sun produces 4 × 1026 joules of energy. It would take 2,000 million nuclear power plants a whole year to produce the same amount of energy on Earth. In the Sun, and in most stars, hydrogen atoms fuse together to form ...
Sakurai`s Object - Department of Physics, HKU
... 4) The “dredge-up” phase: In response to the increasing luminosity coming out from the He burning shell, convective envelope extends down to the extinguished H burning shell. This brings a lot of C into the stellar surface. • The rapid mass loss due to pulsating instability or strong stellar wind b ...
... 4) The “dredge-up” phase: In response to the increasing luminosity coming out from the He burning shell, convective envelope extends down to the extinguished H burning shell. This brings a lot of C into the stellar surface. • The rapid mass loss due to pulsating instability or strong stellar wind b ...
Who’s Afraid of a Stellar Superflare? Rachel Osten GSFC
... superflaring in normal stars -- Schaefer et al. (2000) normal solar-like stars undergoing flaring events with energy releases 1033-1038 ergs, occurring roughly once every 100 years or so ...
... superflaring in normal stars -- Schaefer et al. (2000) normal solar-like stars undergoing flaring events with energy releases 1033-1038 ergs, occurring roughly once every 100 years or so ...
Solar System Formation
... model must match: brightness color (temps) inclination extent (don’t forget star) 80 deg ...
... model must match: brightness color (temps) inclination extent (don’t forget star) 80 deg ...
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.