2.3 Peculiar galaxies
... the centre. Now imagine bringing another galaxy close. Our single star can then feel a force due to both galaxies. The net result is quite complicated, and whats more keeps changing with time, as the galaxies move closer. Rather than moving in a nice simple orbit, the stars do quite complex things. ...
... the centre. Now imagine bringing another galaxy close. Our single star can then feel a force due to both galaxies. The net result is quite complicated, and whats more keeps changing with time, as the galaxies move closer. Rather than moving in a nice simple orbit, the stars do quite complex things. ...
ON STARS, THEIR EVOLUTION AND THEIR STABILITY
... by R. H. Fowler.4 His formulation was the following: The stellar material, in the white-dwarf state, will have radiated so much energy that it has less energy than the same matter in normal atoms expanded at the absolute zero of temperature. If part of it were removed from the star and the pressure ...
... by R. H. Fowler.4 His formulation was the following: The stellar material, in the white-dwarf state, will have radiated so much energy that it has less energy than the same matter in normal atoms expanded at the absolute zero of temperature. If part of it were removed from the star and the pressure ...
ph507rev1
... Because the flux of starlight varies with wavelength, the magnitude of a star depends upon the wavelength at which we observe. Originally, photographic plates were sensitive only to blue light, and the term photographic magnitude (mpg) still refers to magnitudes centred around 420 nm (in the blue re ...
... Because the flux of starlight varies with wavelength, the magnitude of a star depends upon the wavelength at which we observe. Originally, photographic plates were sensitive only to blue light, and the term photographic magnitude (mpg) still refers to magnitudes centred around 420 nm (in the blue re ...
The star-forming environment of an ultraluminous X-ray
... XMM–Newton/Optical Monitor and ground-based data. We find that the ULX is located near a small group of OB stars, but is not associated with any massive young clusters nor with any extraordinary massive stars. The brightest point source in the Chandra error circle is consistent with a single blue su ...
... XMM–Newton/Optical Monitor and ground-based data. We find that the ULX is located near a small group of OB stars, but is not associated with any massive young clusters nor with any extraordinary massive stars. The brightest point source in the Chandra error circle is consistent with a single blue su ...
Bright Stars and Faint Stars: the stellar magnitude system
... • Apparent magnitude is the brightness of an object as it appears to you • System due to Hipparchos (2nd century BC) • Nowadays system made more precise • Magnitude changes are “logarithmic”, each magnitude means factor of 2.512 in brightness • See Table 16.2 ...
... • Apparent magnitude is the brightness of an object as it appears to you • System due to Hipparchos (2nd century BC) • Nowadays system made more precise • Magnitude changes are “logarithmic”, each magnitude means factor of 2.512 in brightness • See Table 16.2 ...
Chapter 2 Surveying the stars 2.1 Star magnitudes
... The brightness of a star in the night sky depends on the intensity of the star’s light at the Earth which is the light energy per second per unit surface area received from the star at normal incidence on a surface. The intensity of sunlight at the Earth’s surface is about 1400 W m−2. In comparison, ...
... The brightness of a star in the night sky depends on the intensity of the star’s light at the Earth which is the light energy per second per unit surface area received from the star at normal incidence on a surface. The intensity of sunlight at the Earth’s surface is about 1400 W m−2. In comparison, ...
The negative equivalent mass of gravitational fields
... 3/4th of the Sun’s mass is in 1/3rd of its full radius, so that the negative mass ratio could be more than twice the value in the table above. This would mean that the Sun’s negative equivalent mass from its gravitational field is about 2.5 parts per million. For larger objects, the average density ...
... 3/4th of the Sun’s mass is in 1/3rd of its full radius, so that the negative mass ratio could be more than twice the value in the table above. This would mean that the Sun’s negative equivalent mass from its gravitational field is about 2.5 parts per million. For larger objects, the average density ...
Central Temperature and Density of Stars in Gravitational Equilibrium
... to hold between the pressure and density throughout the whole interior. Secondly, for a star having a shell structure our consideration is confined to its innermost homogeneous core. The pressure at the core boundary is assumed to be so small compared to the central pressure that the existence of th ...
... to hold between the pressure and density throughout the whole interior. Secondly, for a star having a shell structure our consideration is confined to its innermost homogeneous core. The pressure at the core boundary is assumed to be so small compared to the central pressure that the existence of th ...
Modified True/False - Indicate whether the statement is true or false
... ____ 16. HS-ESS1-1 The process in which smaller atomic nuclei combine into larger atomic nuclei is known as a. Gravitational attraction. c. The Doppler effect. b. Parallax. d. Nuclear fusion. ____ 17. HS-ESS1-2 The apparent shift in a star’s position caused by the motion of the observer is called __ ...
... ____ 16. HS-ESS1-1 The process in which smaller atomic nuclei combine into larger atomic nuclei is known as a. Gravitational attraction. c. The Doppler effect. b. Parallax. d. Nuclear fusion. ____ 17. HS-ESS1-2 The apparent shift in a star’s position caused by the motion of the observer is called __ ...
The central star of the planetary nebula PB 8: a Wolf-Rayet
... we find that its surface composition is hydrogen-deficient, but not carbon-rich. With mass fractions of 55% helium, 40% hydrogen, 1.3% carbon, 2% nitrogen, and 1.3% oxygen, it differs greatly from the 30–50% of carbon which are typically seen in [WC]-type central stars. The atmospheric mixture in PB ...
... we find that its surface composition is hydrogen-deficient, but not carbon-rich. With mass fractions of 55% helium, 40% hydrogen, 1.3% carbon, 2% nitrogen, and 1.3% oxygen, it differs greatly from the 30–50% of carbon which are typically seen in [WC]-type central stars. The atmospheric mixture in PB ...
19. Our Galaxy 19.1 The Milky Way Revealed Our goals for learning
... gas in bubbles and superbubbles emits X rays. Gamma rays come from collisions of cosmic rays with atomic nuclei. ...
... gas in bubbles and superbubbles emits X rays. Gamma rays come from collisions of cosmic rays with atomic nuclei. ...
ES Chapter 30
... – A binary star is two stars that are gravitationally bound together and that orbit a common center of mass. – More than half of the stars in the sky are either binary stars or members of multiple-star systems. – Astronomers are able to identify binary stars through several methods. • Accurate measu ...
... – A binary star is two stars that are gravitationally bound together and that orbit a common center of mass. – More than half of the stars in the sky are either binary stars or members of multiple-star systems. – Astronomers are able to identify binary stars through several methods. • Accurate measu ...
18th Cambridge Workshop on Cool Stars, Stellar Systems, and the... Proceedings of Lowell Observatory (9-13 June 2014)
... development of life and is therefore of potential importance for habitability. Understanding the effects of space weather on solar system planets and exoplanets helps us not only to constrain habitability but is also useful to characterise exoplanetary systems. For instance, planetary radio emission ...
... development of life and is therefore of potential importance for habitability. Understanding the effects of space weather on solar system planets and exoplanets helps us not only to constrain habitability but is also useful to characterise exoplanetary systems. For instance, planetary radio emission ...
The Propagation and Eruption of Relativistic Jets from the
... • Jets inside massive stars have been studied numerically in both Newtonian (MacFadyen & Woosley 1999 etc.) and relativistic simulations (Aloy et al. 2000; Zhang et al. 2003) – The collapsar model is able to explain many of the observed characteristics of GRBs – Require further examination, especial ...
... • Jets inside massive stars have been studied numerically in both Newtonian (MacFadyen & Woosley 1999 etc.) and relativistic simulations (Aloy et al. 2000; Zhang et al. 2003) – The collapsar model is able to explain many of the observed characteristics of GRBs – Require further examination, especial ...
2015 SAO Summer Intern AAS Abstracts - Harvard
... its radius, semi-major axis, and orbital period. For the latter property, there is a distinct lack of planets with periods between 10 to 100 days. This gap could be caused by something as simple as observational bias, or as prominent as planetary formation or migration. Here, we report an investigat ...
... its radius, semi-major axis, and orbital period. For the latter property, there is a distinct lack of planets with periods between 10 to 100 days. This gap could be caused by something as simple as observational bias, or as prominent as planetary formation or migration. Here, we report an investigat ...
Resolved SPs : simulations
... •The method requires a lot of computing: Does this really improve the solution? (apart from giving a quantitative estimate of the quality of the fit) Dolphin: “ The solution with RGB+HB was extremely successful, measuring …the SFH with nearly the same accuracy as the fit to the entire CMD.” ...
... •The method requires a lot of computing: Does this really improve the solution? (apart from giving a quantitative estimate of the quality of the fit) Dolphin: “ The solution with RGB+HB was extremely successful, measuring …the SFH with nearly the same accuracy as the fit to the entire CMD.” ...
Galaxies and Stars
... A) main sequence star with a temperature of approximately 4,000ºC and a luminosity of 100 B) main sequence star with a temperature of approximately 6,000ºC and a luminosity of 1 C) white dwarf star with a temperature of approximately 10,000ºC and a luminosity of ...
... A) main sequence star with a temperature of approximately 4,000ºC and a luminosity of 100 B) main sequence star with a temperature of approximately 6,000ºC and a luminosity of 1 C) white dwarf star with a temperature of approximately 10,000ºC and a luminosity of ...
The Sun
... – A binary star is two stars that are gravitationally bound together and that orbit a common center of mass. – More than half of the stars in the sky are either binary stars or members of multiple-star systems. – Astronomers are able to identify binary stars through several methods. • Accurate measu ...
... – A binary star is two stars that are gravitationally bound together and that orbit a common center of mass. – More than half of the stars in the sky are either binary stars or members of multiple-star systems. – Astronomers are able to identify binary stars through several methods. • Accurate measu ...
Papervision3D star (sun) tutorial and source - 02
... a Perlin noise map that would function as a flare animation. In the end I settled for a two plane solution where one slowly grows and finally fades out at which point the second fades in, rotated randomly and grows until it fades out again. Rinse and repeat. When calibrated carefully, the resizing, ...
... a Perlin noise map that would function as a flare animation. In the end I settled for a two plane solution where one slowly grows and finally fades out at which point the second fades in, rotated randomly and grows until it fades out again. Rinse and repeat. When calibrated carefully, the resizing, ...
arXiv:1502.04693v1 [gr
... WISE (Cushing et al. 2011, Kirkpatrick et al. 2012, Tinney et al. 2012, Kirkpatrick et al. 2013, Cushing et al. 2014a, and Pinfield et al. 2014). The Y0 dwarf WISE J1217+16B was identified as a companion to a T8.5 dwarf, itself identified by WISE (Liu et al. 2012, Leggett et al. 2014a). Three object ...
... WISE (Cushing et al. 2011, Kirkpatrick et al. 2012, Tinney et al. 2012, Kirkpatrick et al. 2013, Cushing et al. 2014a, and Pinfield et al. 2014). The Y0 dwarf WISE J1217+16B was identified as a companion to a T8.5 dwarf, itself identified by WISE (Liu et al. 2012, Leggett et al. 2014a). Three object ...
S E D
... increase its degree of ionization instead of temperature and pressure, while in a fully ionized gas, the temperature and pressure will raise more. Both these equations make up the equation of state, since they both tell us about the state variables; P,T, p and u (internal energy). Another equation o ...
... increase its degree of ionization instead of temperature and pressure, while in a fully ionized gas, the temperature and pressure will raise more. Both these equations make up the equation of state, since they both tell us about the state variables; P,T, p and u (internal energy). Another equation o ...
Deep Chandra Observations of the Arches and Quintuplet Clusters at... Hui Dong Q. Daniel Wang ( &
... The diffuse emission has a spectrum that is substantially harder than that of the point-like sources. In the core region (e.g. ≤ 15”, for Arches). The potential contamination of faint undetected point-like sources could be upto ∼ 65%, but mostly at energies ≤ 4 keV. The remaining diffuse emission ca ...
... The diffuse emission has a spectrum that is substantially harder than that of the point-like sources. In the core region (e.g. ≤ 15”, for Arches). The potential contamination of faint undetected point-like sources could be upto ∼ 65%, but mostly at energies ≤ 4 keV. The remaining diffuse emission ca ...
Neutron Stars
... Periods shorter than this do not exist (such as in the previous calculation) because the object would have to rotate so fast it would overcome gravity and fly apart. ...
... Periods shorter than this do not exist (such as in the previous calculation) because the object would have to rotate so fast it would overcome gravity and fly apart. ...
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.