Neutron Degeneracy Pressure
... discussing degeneracy pressure. The Pauli Exclusion Principle can also be applied to further our understanding of stars, black holes, supernovae, and many other celestial objects and phenomena studied in astrophysics. A vital application is the degeneracy pressure found in the interior of a white dw ...
... discussing degeneracy pressure. The Pauli Exclusion Principle can also be applied to further our understanding of stars, black holes, supernovae, and many other celestial objects and phenomena studied in astrophysics. A vital application is the degeneracy pressure found in the interior of a white dw ...
SOFT X-RAY EMISSIONS FROM PLANETS, MOONS, AND COMETS
... flare. The grid in the picture is in geomagnetic coordinates, and the numbers shown in red are magnetic local time. The terminator at the surface of the Earth is shown as a red dashed line. ...
... flare. The grid in the picture is in geomagnetic coordinates, and the numbers shown in red are magnetic local time. The terminator at the surface of the Earth is shown as a red dashed line. ...
ph507weeks1
... Distance: Distance is an easy concept to understand: it is just a length in some units such as in feet, km, light years, parsecs etc. It has been excrutiatingly difficult to measure astronomical distances until this century. Unfortunately most stars are so far away that it is impossible to directly ...
... Distance: Distance is an easy concept to understand: it is just a length in some units such as in feet, km, light years, parsecs etc. It has been excrutiatingly difficult to measure astronomical distances until this century. Unfortunately most stars are so far away that it is impossible to directly ...
Chapter 7 Stellar models and stellar stability
... where B ∝ L/M = constant and C is an integration constant, determined by the boundary conditions. For the Kramers opacity, which is a reasonable approximation for stellar envelopes of moderate temperatures, we find T 8.5 = B (P2 + C). The different possible solutions are characterized by the√value o ...
... where B ∝ L/M = constant and C is an integration constant, determined by the boundary conditions. For the Kramers opacity, which is a reasonable approximation for stellar envelopes of moderate temperatures, we find T 8.5 = B (P2 + C). The different possible solutions are characterized by the√value o ...
HD 100453: An Evolutionary link between
... If motion through space is common, they are likely physical companions ...
... If motion through space is common, they are likely physical companions ...
Continuous Spectrum—Kirchoff`s First Law
... Visual binaries, which can be seen in the telescope as two separate stars, are especially useful to astronomers. Over time, we can watch the two stars orbit around each other. We can measure the size of the orbit, and can calculate its actual size (in A.U.) if we know the distance of the binary. We ...
... Visual binaries, which can be seen in the telescope as two separate stars, are especially useful to astronomers. Over time, we can watch the two stars orbit around each other. We can measure the size of the orbit, and can calculate its actual size (in A.U.) if we know the distance of the binary. We ...
Fulltext
... (4) scalar fields (which may account for the origin of masses). It is therefore natural to ask whether there exist stable stellar configurations other than dwarfs, neutron stars, and black holes. The central density of a typical neutron star is often greater than several times the nuclear matter den ...
... (4) scalar fields (which may account for the origin of masses). It is therefore natural to ask whether there exist stable stellar configurations other than dwarfs, neutron stars, and black holes. The central density of a typical neutron star is often greater than several times the nuclear matter den ...
ABSOLUTE AND APPARENT MAGNITUDES
... As a general (not vastly accurate, but close enough) rule of thumb, the highest apparent magnitude that the naked eye can see under ideal viewing conditions is about +6. Objects can cast visible shadows around an apparent magnitude -4 (you’d need a very dark night to see them though - they’d get pr ...
... As a general (not vastly accurate, but close enough) rule of thumb, the highest apparent magnitude that the naked eye can see under ideal viewing conditions is about +6. Objects can cast visible shadows around an apparent magnitude -4 (you’d need a very dark night to see them though - they’d get pr ...
Dark Matter Search
... • In early March, the LAT skywatchers found a new, flaring gamma-ray source in the Cygnus region. ...
... • In early March, the LAT skywatchers found a new, flaring gamma-ray source in the Cygnus region. ...
Planetary Nebula
... A dying star that was once about five times the mass of the Sun is at the center of this fury. It has ejected its envelope of gases and is now unleashing a stream of ultraviolet radiation that is making the cast-off material glow. This object is an example of a planetary nebula, so-named because man ...
... A dying star that was once about five times the mass of the Sun is at the center of this fury. It has ejected its envelope of gases and is now unleashing a stream of ultraviolet radiation that is making the cast-off material glow. This object is an example of a planetary nebula, so-named because man ...
The Eight Parts of Speech:
... ALTER means other. An alteration is to make something other than what it was; an alternative is another option, and altruism is thinking of others. ...
... ALTER means other. An alteration is to make something other than what it was; an alternative is another option, and altruism is thinking of others. ...
transparencies
... fading emission following the GRB (Costa et al. 1997) • Observed at all wavelengths (radio to X-ray) • Detectable for days to weeks. ...
... fading emission following the GRB (Costa et al. 1997) • Observed at all wavelengths (radio to X-ray) • Detectable for days to weeks. ...
4. Stars and resolved stellar populations
... innermost regions of jets with ALMA and SINFONI. In the mm range, ALMA will trace the cool (< 500 K) molecular flow at very high spectral resolution (0.1 km/s). In the near-IR, SINFONI will trace warmer molecular gas (2000 K) in H2 as well as hot atomic jets in [Fe II] and He I, with 75 km/s resolut ...
... innermost regions of jets with ALMA and SINFONI. In the mm range, ALMA will trace the cool (< 500 K) molecular flow at very high spectral resolution (0.1 km/s). In the near-IR, SINFONI will trace warmer molecular gas (2000 K) in H2 as well as hot atomic jets in [Fe II] and He I, with 75 km/s resolut ...
in search of antimatter in the universe
... decreases with radius, and the number of stars reaches a maximum relatively close to the centre of the galaxy. The total number of stars calculated from the graph is 8.4 x 1011, similar to that observed in most galaxies, so our model of the galaxy is realistic. It is also important to consider what ...
... decreases with radius, and the number of stars reaches a maximum relatively close to the centre of the galaxy. The total number of stars calculated from the graph is 8.4 x 1011, similar to that observed in most galaxies, so our model of the galaxy is realistic. It is also important to consider what ...
ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF... J. M. Torrejón , N. S. Schulz , M. A. Nowak
... Cassinelly 2007). One of the models developed to accommodate these finding suggests that sub-surface convection may play a role in massive stars, resulting in surface magnetic spots and causing the clumping to already originate at the photosphere (Cantiello & Braithwaite 2011). In high-mass X-ray bin ...
... Cassinelly 2007). One of the models developed to accommodate these finding suggests that sub-surface convection may play a role in massive stars, resulting in surface magnetic spots and causing the clumping to already originate at the photosphere (Cantiello & Braithwaite 2011). In high-mass X-ray bin ...
Neutron stars as probes of extreme energy density matter
... for. A case in point is RX J1856−3754, the nearest known neutron star. Depending upon the atmospheric model used, the inferred masses vary significantly, although the radii are similar (see table 3). Non-magnetic heavy element atmospheres [23,24] predict spectral features that are not observed. Foll ...
... for. A case in point is RX J1856−3754, the nearest known neutron star. Depending upon the atmospheric model used, the inferred masses vary significantly, although the radii are similar (see table 3). Non-magnetic heavy element atmospheres [23,24] predict spectral features that are not observed. Foll ...
Chapter 5 Nuclear reactions in stars
... laws of thermodynamics. Eq. (6.4) is generalized to include both the cases of radiative and convective energy transport. The term ∆∇ is the superadiabaticity of the temperature gradient that must follow from a theory of convection (in practice, the mixing length theory); for the interior one can ta ...
... laws of thermodynamics. Eq. (6.4) is generalized to include both the cases of radiative and convective energy transport. The term ∆∇ is the superadiabaticity of the temperature gradient that must follow from a theory of convection (in practice, the mixing length theory); for the interior one can ta ...
3. Solar System Formation and Early Evolution
... 1987; André and Montmerle, 1994; André et al., 2000, a summary and recent references are given in Feigelson and Montmerle, 1999, and Montmerle, 2005: Figure 3.7). At the so-called ‘‘protostellar stage’’, a vast, dense envelope (1,000–10,000 AU in radius) is detectable, and from the center emerges ...
... 1987; André and Montmerle, 1994; André et al., 2000, a summary and recent references are given in Feigelson and Montmerle, 1999, and Montmerle, 2005: Figure 3.7). At the so-called ‘‘protostellar stage’’, a vast, dense envelope (1,000–10,000 AU in radius) is detectable, and from the center emerges ...
this paper
... center), which were adjusted to ensure that the reflected laser beam was centered on the collimating aperture, even as the mirror chamber was rotated. In this manner, the mirror’s axis was aligned to the beamline axis to within 1 cm along an 8.5 m length, for an accuracy of about ±0.001 radians. Bei ...
... center), which were adjusted to ensure that the reflected laser beam was centered on the collimating aperture, even as the mirror chamber was rotated. In this manner, the mirror’s axis was aligned to the beamline axis to within 1 cm along an 8.5 m length, for an accuracy of about ±0.001 radians. Bei ...
From ATLASGAL to SEDIGISM: Towards a Complete 3D View of the
... 20 % of these filaments, preferentially within the ones with the largest mass-tolength ratios. Moreover, these filaments are predominantly aligned with the Galactic Plane, and associated with the spiral arms. This seems to indicate a direct link between star formation activity and large scale Galact ...
... 20 % of these filaments, preferentially within the ones with the largest mass-tolength ratios. Moreover, these filaments are predominantly aligned with the Galactic Plane, and associated with the spiral arms. This seems to indicate a direct link between star formation activity and large scale Galact ...
G040141-00 - DCC
... • Normal modes excited due to glitches in Vela will have an amplitude of 10–24 • It is possible that a newly born NS can be observed in normal modes in our own Galaxy ...
... • Normal modes excited due to glitches in Vela will have an amplitude of 10–24 • It is possible that a newly born NS can be observed in normal modes in our own Galaxy ...
A star`s life is a struggle between ______ wanting to crush it, and
... b) The red giant might be made of some different elements, so it evolved faster. c) The lower mass star used to be a more massive main sequence star, but when it became a giant some of its mass was transferred to the other star. ...
... b) The red giant might be made of some different elements, so it evolved faster. c) The lower mass star used to be a more massive main sequence star, but when it became a giant some of its mass was transferred to the other star. ...
Stellar models and stellar stability
... Such models are called polytropic models. The properties of polytropic stellar models were examined in the computer practicum, and are covered by Chapter 19 of K & W, sections 19.1–7 and 19.9. In the second approach we consider simple scaling relations between stellar models with dif ...
... Such models are called polytropic models. The properties of polytropic stellar models were examined in the computer practicum, and are covered by Chapter 19 of K & W, sections 19.1–7 and 19.9. In the second approach we consider simple scaling relations between stellar models with dif ...
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.