Basics of Astrophysics
... The speckle pattern change rapidly, if v is the speed of the wind the timescale can be roughly estimated by t = r/v where r is the size of the cell causing the speckle. With a rather ...
... The speckle pattern change rapidly, if v is the speed of the wind the timescale can be roughly estimated by t = r/v where r is the size of the cell causing the speckle. With a rather ...
Today`s Powerpoint
... Composition unknown. Probably mostly exotic particles that don't interact with ordinary matter at all (except gravity). Some may be brown dwarfs, dead white dwarfs … Most likely it's a dark halo surrounding the Milky Way. ...
... Composition unknown. Probably mostly exotic particles that don't interact with ordinary matter at all (except gravity). Some may be brown dwarfs, dead white dwarfs … Most likely it's a dark halo surrounding the Milky Way. ...
Hard X-ray Sky - High Energy Astrophysics
... Sub-giants with WD cores are gravitational wave LISA triggers. ...
... Sub-giants with WD cores are gravitational wave LISA triggers. ...
Unit 8 Chapter 30
... average star, Rigel has an Absolute Magnitude of -6.4 which makes it appear brighter than most stars. Remember, all stars are not the same distance away, therefore, a faint star may really be very bright if it were closer. ...
... average star, Rigel has an Absolute Magnitude of -6.4 which makes it appear brighter than most stars. Remember, all stars are not the same distance away, therefore, a faint star may really be very bright if it were closer. ...
The Milky Way Galaxy
... Let’s start by studying a special galaxy, our own: The Milky Way The basic structures of the Milky Way Galaxy: bulge, disk, halo What happens inside the Milky Way: the-star-gas-star cycle The motions of the Milky Way: how they happen and where; What do they mean, and what they are useful for? The my ...
... Let’s start by studying a special galaxy, our own: The Milky Way The basic structures of the Milky Way Galaxy: bulge, disk, halo What happens inside the Milky Way: the-star-gas-star cycle The motions of the Milky Way: how they happen and where; What do they mean, and what they are useful for? The my ...
Document
... 2000 km/s. While our own Sun loses approximately 10−14 solar masses every year, Wolf–Rayet stars typically lose 10−5 solar masses a year.[1] • Wolf–Rayet stars are extremely hot, with surface temperatures in the range of 30,000 K to around 200,000K.[2] • They are also highly luminous. (not necessari ...
... 2000 km/s. While our own Sun loses approximately 10−14 solar masses every year, Wolf–Rayet stars typically lose 10−5 solar masses a year.[1] • Wolf–Rayet stars are extremely hot, with surface temperatures in the range of 30,000 K to around 200,000K.[2] • They are also highly luminous. (not necessari ...
Active Galactic Nuclei: are they important?
... •Active Galactic Nuclei are fantastic subject for somebody who likes to apply GR •They consist of a massive black hole surrounded by plentiful material flowing in and out •This material emits radiation so we can trace what is happening close to a black hole ...
... •Active Galactic Nuclei are fantastic subject for somebody who likes to apply GR •They consist of a massive black hole surrounded by plentiful material flowing in and out •This material emits radiation so we can trace what is happening close to a black hole ...
The Galaxies
... studying how the stars in our galaxy move, we can tell that most of the galaxy’s mass is in the corona, in a form that doesn’t give off light. ► It is called dark matter. ► We’re not sure what it is, although there are several very good ideas. ...
... studying how the stars in our galaxy move, we can tell that most of the galaxy’s mass is in the corona, in a form that doesn’t give off light. ► It is called dark matter. ► We’re not sure what it is, although there are several very good ideas. ...
Supermassive black holes
... of a protogalactic cloud determine whether a galaxy formed into a spiral or an elliptical galaxy? ...
... of a protogalactic cloud determine whether a galaxy formed into a spiral or an elliptical galaxy? ...
Ia 超新星的
... The light curve peak lasts for several days, and displays exponential decline at late time Most of SNe Ia show relatively similar spectra and light curves shapes, but definite departures from the canonical events have also been observed. SNe Ia explosion have been detected in galaxies of all Hubble ...
... The light curve peak lasts for several days, and displays exponential decline at late time Most of SNe Ia show relatively similar spectra and light curves shapes, but definite departures from the canonical events have also been observed. SNe Ia explosion have been detected in galaxies of all Hubble ...
Chapter 14 The Milky Way Galaxy
... The galactic halo and globular clusters formed very early; the halo is essentially spherical. All the stars in the halo are very old, and there is no gas and dust. The galactic disk is where the youngest stars are, as well as star formation regions – emission nebulae, large clouds of gas and ...
... The galactic halo and globular clusters formed very early; the halo is essentially spherical. All the stars in the halo are very old, and there is no gas and dust. The galactic disk is where the youngest stars are, as well as star formation regions – emission nebulae, large clouds of gas and ...
Astronomy 110 Announcements: How are the lives of stars with
... what would happen if a star orbiting in a direction opposite the neutron’s star rotation fell onto a neutron star? A. The neutron star’s rotation would speed up. B. The neutron star’s rotation would slow down. C. Nothing, the directions would cancel each other ...
... what would happen if a star orbiting in a direction opposite the neutron’s star rotation fell onto a neutron star? A. The neutron star’s rotation would speed up. B. The neutron star’s rotation would slow down. C. Nothing, the directions would cancel each other ...
Document
... Trumpler showed that there is dust material between the stars and that the extinction of starlight is caused by the scattering of light out of the line of sight. This caused early observers to (although they recognized the disk shape of the milky way by observing star clusters) overestimate the diam ...
... Trumpler showed that there is dust material between the stars and that the extinction of starlight is caused by the scattering of light out of the line of sight. This caused early observers to (although they recognized the disk shape of the milky way by observing star clusters) overestimate the diam ...
Astronomy
... This event recurs and happens when one of the companions in the binary system is a white dwarf. A. Nova B. Type I supernova C. Type II supernova D. Pulsar E. None of the above ...
... This event recurs and happens when one of the companions in the binary system is a white dwarf. A. Nova B. Type I supernova C. Type II supernova D. Pulsar E. None of the above ...
Chapter 15, Galaxies
... Because the mass of white dwarfs when they explode as supernovae is always around 1.0 M⊙, its luminosity is very consistent, and can be used as a standard candle for the measurement of distance to distant galaxies (Chapter 15). The amount of energy produced by white dwarf supernovae and massive star ...
... Because the mass of white dwarfs when they explode as supernovae is always around 1.0 M⊙, its luminosity is very consistent, and can be used as a standard candle for the measurement of distance to distant galaxies (Chapter 15). The amount of energy produced by white dwarf supernovae and massive star ...
observing the universe
... A galaxy is an assembly of between a billion (109) and a hundred billion (1011) stars. There is often a large amount of dust and gas intermingled, all held together by gravity. The Sun and Earth are in the Milky Way Galaxy. Galaxies have many different characteristics, but the easiest way to classif ...
... A galaxy is an assembly of between a billion (109) and a hundred billion (1011) stars. There is often a large amount of dust and gas intermingled, all held together by gravity. The Sun and Earth are in the Milky Way Galaxy. Galaxies have many different characteristics, but the easiest way to classif ...
Beyond the Rainbow
... ultraviolet to sneak through. This protects us from harmful ultraviolet light and x rays from solar magnetic storms. Much of the ultraviolet is blocked by ozone high in the stratosphere. Without this ozone layer, living on Earth's surface would be hazardous to one's health. So what can astronomers d ...
... ultraviolet to sneak through. This protects us from harmful ultraviolet light and x rays from solar magnetic storms. Much of the ultraviolet is blocked by ozone high in the stratosphere. Without this ozone layer, living on Earth's surface would be hazardous to one's health. So what can astronomers d ...
Hubble`s Use of Cepheids (PDF version)
... these stars on photographs and had described that to Shapley, when he was still working at Mount Wilson. (Shapley later moved to Harvard.) Shapley had dismissed this as impossible – he ‘knew’ that the spiral nebulae were small, nearby objects. It was galling for him to see Hubble credited with this ...
... these stars on photographs and had described that to Shapley, when he was still working at Mount Wilson. (Shapley later moved to Harvard.) Shapley had dismissed this as impossible – he ‘knew’ that the spiral nebulae were small, nearby objects. It was galling for him to see Hubble credited with this ...
The Hubble Redshift Distance Relation
... (you can change how quickly the telescope moves - or slews - by clicking on the Slew Rate button). Next, click on Change View to change from the finder scope to the spectrometer. You will see an enlarged view of the galaxy. Once again, use the “N”, “W”, “S”, “E” buttons to move the telescope until t ...
... (you can change how quickly the telescope moves - or slews - by clicking on the Slew Rate button). Next, click on Change View to change from the finder scope to the spectrometer. You will see an enlarged view of the galaxy. Once again, use the “N”, “W”, “S”, “E” buttons to move the telescope until t ...
Astronomy Final C - Tarleton State University
... 46. Which of the following is true? A.baryons form quarks and gluons B.quarks and gluons form baryons C.both of these may be true 47. The most widely accepted theory for the cause of Cosmic Inflation is A.Baryogenesis B.Annihilation C.Pair Production D.Phase Change E.Decoupling 48. In the productio ...
... 46. Which of the following is true? A.baryons form quarks and gluons B.quarks and gluons form baryons C.both of these may be true 47. The most widely accepted theory for the cause of Cosmic Inflation is A.Baryogenesis B.Annihilation C.Pair Production D.Phase Change E.Decoupling 48. In the productio ...
notes
... Wide Field and Planetary Camera 2 (WFPC2) for ten consecutive days between December 18 and 28, 1995. 1,500 galaxies at various stages of evolution. Most of the galaxies are so faint (nearly 30th magnitude or about four-billion times fainter than can be seen by the human eye) they have never before b ...
... Wide Field and Planetary Camera 2 (WFPC2) for ten consecutive days between December 18 and 28, 1995. 1,500 galaxies at various stages of evolution. Most of the galaxies are so faint (nearly 30th magnitude or about four-billion times fainter than can be seen by the human eye) they have never before b ...
Gamma-ray burst
Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They are the brightest electromagnetic events known to occur in the universe. Bursts can last from ten milliseconds to several hours. The initial burst is usually followed by a longer-lived ""afterglow"" emitted at longer wavelengths (X-ray, ultraviolet, optical, infrared, microwave and radio).Most observed GRBs are believed to consist of a narrow beam of intense radiation released during a supernova or hypernova as a rapidly rotating, high-mass star collapses to form a neutron star, quark star, or black hole. A subclass of GRBs (the ""short"" bursts) appear to originate from a different process – this may be due to the merger of binary neutron stars. The cause of the precursor burst observed in some of these short events may be due to the development of a resonance between the crust and core of such stars as a result of the massive tidal forces experienced in the seconds leading up to their collision, causing the entire crust of the star to shatter.The sources of most GRBs are billions of light years away from Earth, implying that the explosions are both extremely energetic (a typical burst releases as much energy in a few seconds as the Sun will in its entire 10-billion-year lifetime) and extremely rare (a few per galaxy per million years). All observed GRBs have originated from outside the Milky Way galaxy, although a related class of phenomena, soft gamma repeater flares, are associated with magnetars within the Milky Way. It has been hypothesized that a gamma-ray burst in the Milky Way, pointing directly towards the Earth, could cause a mass extinction event.GRBs were first detected in 1967 by the Vela satellites, a series of satellites designed to detect covert nuclear weapons tests. Hundreds of theoretical models were proposed to explain these bursts in the years following their discovery, such as collisions between comets and neutron stars. Little information was available to verify these models until the 1997 detection of the first X-ray and optical afterglows and direct measurement of their redshifts using optical spectroscopy, and thus their distances and energy outputs. These discoveries, and subsequent studies of the galaxies and supernovae associated with the bursts, clarified the distance and luminosity of GRBs. These facts definitively placed them in distant galaxies and also connected long GRBs with the explosion of massive stars, the only possible source for the energy outputs observed.