Document
... where 1 is the radial point at which density becomes zero (the “surface” of the star) and depends only on the polytropic index n. Note that for 01, R decreases.
Similarly,
3n
(n 1)K
M f (1 ) 4
c 2n
...
... where 1 is the radial point at which density becomes zero (the “surface” of the star) and depends only on the polytropic index n. Note that for 0
Neutron Density and Neutron Source Determination in Barium
... neutron density, would be a significant advance towards this goal. Knowledge of these two parameters would allow strong constraints to be placed on any evolutionary hypothesis purporting to explain the Ba 11 star phenomenon. Hitherto, the neutron source has been analysed in only two Ba II stars, and ...
... neutron density, would be a significant advance towards this goal. Knowledge of these two parameters would allow strong constraints to be placed on any evolutionary hypothesis purporting to explain the Ba 11 star phenomenon. Hitherto, the neutron source has been analysed in only two Ba II stars, and ...
Bayesian mass and age estimates for transiting exoplanet host stars⋆
... [Fe/H]s derived from the analysis of the spectrum (Doyle et al. 2013). This is at least a factor of 3 lower than the minimum standard error that we have assumed for [Fe/H]s so we ignore this weak correlation between T eff and [Fe/H]s . For a few stars the effective temperature can be determined direct ...
... [Fe/H]s derived from the analysis of the spectrum (Doyle et al. 2013). This is at least a factor of 3 lower than the minimum standard error that we have assumed for [Fe/H]s so we ignore this weak correlation between T eff and [Fe/H]s . For a few stars the effective temperature can be determined direct ...
Role of column density in the formation of stars
... central black holes in galactic nuclei scale approximately with the fourth power of the bulge velocity dispersion. It is shown here that these relations can be accounted for if, in a forming galaxy with an isothermal mass distribution, gas with a column density above about 8 M pc−2 goes into stars, ...
... central black holes in galactic nuclei scale approximately with the fourth power of the bulge velocity dispersion. It is shown here that these relations can be accounted for if, in a forming galaxy with an isothermal mass distribution, gas with a column density above about 8 M pc−2 goes into stars, ...
Dark Stars: Dark Matter annihilation can power the first stars
... • DM particles are their own antipartners, and annihilate more and more rapidly as the density increases • DM annihilates to e+/e- and photon endproducts of 100 GeV (or so) which collide with hydrogen, are trapped inside the cloud, and heat it up. • At a high enough DM density, the DM heating ove ...
... • DM particles are their own antipartners, and annihilate more and more rapidly as the density increases • DM annihilates to e+/e- and photon endproducts of 100 GeV (or so) which collide with hydrogen, are trapped inside the cloud, and heat it up. • At a high enough DM density, the DM heating ove ...
Article PDF - IOPscience
... an old (ⲏ10 Gyr), metal-poor ([Fe/H] ∼ ⫺2.0), and spatially extended population along with a much younger (∼1.4–2.0 Gyr), 0.5 dex more metal-rich, and spatially more concentrated population. These young stars are also offset by 64⫹40 ⫺20 pc to the east of the galaxy center. The data suggest that thi ...
... an old (ⲏ10 Gyr), metal-poor ([Fe/H] ∼ ⫺2.0), and spatially extended population along with a much younger (∼1.4–2.0 Gyr), 0.5 dex more metal-rich, and spatially more concentrated population. These young stars are also offset by 64⫹40 ⫺20 pc to the east of the galaxy center. The data suggest that thi ...
The Stellar Population And Origin Of The Mysterious K.V. Getman
... The mysterious high galactic latitude cometary globule (CG) CG12 has been observed with the ACIS detector on board the Chandra X-ray Observatory. We detect 128 X-ray sources, of which a half are likely young stars formed within the globule's head. This new population of >=50 T-Tauri stars and one ne ...
... The mysterious high galactic latitude cometary globule (CG) CG12 has been observed with the ACIS detector on board the Chandra X-ray Observatory. We detect 128 X-ray sources, of which a half are likely young stars formed within the globule's head. This new population of >=50 T-Tauri stars and one ne ...
TWO NEW VARIABLE STARS OBSERVED IN THE FIELD OF THE
... This leads to the de-reddened estimate for the index color (V-R)average=0.347±0.009, which is typical of a F2 type main sequence star, as reported in Zombek (1990). Considering the shape of the light curve, the values found for the pulsation period, magnitude variations and V-R index, we suggest tha ...
... This leads to the de-reddened estimate for the index color (V-R)average=0.347±0.009, which is typical of a F2 type main sequence star, as reported in Zombek (1990). Considering the shape of the light curve, the values found for the pulsation period, magnitude variations and V-R index, we suggest tha ...
Lithium production by thermohaline mixing in low
... Figure 1. Abundance profiles of the 1.5 M model after its second thermal pulse. In each panel, the abundances are: 3 He (dot-short dash line), 7 Be (dot-long dash line) and 7 Li (dashed line). The mean molecular weight, µ, is displayed by a solid line. The grey shading indicates convective regions. ...
... Figure 1. Abundance profiles of the 1.5 M model after its second thermal pulse. In each panel, the abundances are: 3 He (dot-short dash line), 7 Be (dot-long dash line) and 7 Li (dashed line). The mean molecular weight, µ, is displayed by a solid line. The grey shading indicates convective regions. ...
Hot HB stars in globular clusters
... of about 4 . 7, which places it at the very faint blue end of the EHB as seen in the colour-magnitude diagram of NGC 6752. F2-2 may even be hotter than any EHB star in NGC 6752. From its proximity to the helium main sequence in Fig. 4 and 5 it might be tempting to regard F2-2 as a naked helium core, ...
... of about 4 . 7, which places it at the very faint blue end of the EHB as seen in the colour-magnitude diagram of NGC 6752. F2-2 may even be hotter than any EHB star in NGC 6752. From its proximity to the helium main sequence in Fig. 4 and 5 it might be tempting to regard F2-2 as a naked helium core, ...
The spectroscopic Hertzsprung-Russell diagram
... the understanding of stellar evolution since more than hundred years (Nielsen 1964). Hertzsprung (1905) and later independently Russell (1919) realized that the knowledge of the absolute brightness of stars, or at least of the absolute brightness differences, together with their spectral type or sur ...
... the understanding of stellar evolution since more than hundred years (Nielsen 1964). Hertzsprung (1905) and later independently Russell (1919) realized that the knowledge of the absolute brightness of stars, or at least of the absolute brightness differences, together with their spectral type or sur ...
The IMF of intermediate-mass stars in young star clusters
... the MF steeper. Thus, one can say that, although both the corrections increase with decreasing stellar brightness, they affect the MF slope in exactly the opposite way. The change in MF slope can be significant, if the corrections are large. Dependence of MF slope on the mass loss rate: In extremely ...
... the MF steeper. Thus, one can say that, although both the corrections increase with decreasing stellar brightness, they affect the MF slope in exactly the opposite way. The change in MF slope can be significant, if the corrections are large. Dependence of MF slope on the mass loss rate: In extremely ...
the paper - Universitäts
... of He 2-131 (middle), since its mass loss rate is obviously too small, as evidenced by the presence of almost only purely photospheric lines hardly influenced by the thin wind – indicating that this CSPN must have a much larger luminosity, because L is the major factor determining the mass loss rate ...
... of He 2-131 (middle), since its mass loss rate is obviously too small, as evidenced by the presence of almost only purely photospheric lines hardly influenced by the thin wind – indicating that this CSPN must have a much larger luminosity, because L is the major factor determining the mass loss rate ...
Globular cluster absolute ages from cooling brown dwarfs
... they contract and become fainter and bluer, can last for billions of years, depending on the mass of the object. Fig. 1 depicts the evolution in luminosity for stars in this transition region between low mass stars and BDs. The mass range is for illustration only, since, for these models, we used th ...
... they contract and become fainter and bluer, can last for billions of years, depending on the mass of the object. Fig. 1 depicts the evolution in luminosity for stars in this transition region between low mass stars and BDs. The mass range is for illustration only, since, for these models, we used th ...
The diameter of the CoRoT target HD 49933
... We use the state-of-the-art radiative hydrodynamical code (STAGGER CODE, Nordlund & Galsgaard2) to simulate the surface convection and stratification of HD 49933. In a local box, the code solves the full set of conservative hydrodynamical equations coupled to an accurate treatment of the radiative t ...
... We use the state-of-the-art radiative hydrodynamical code (STAGGER CODE, Nordlund & Galsgaard2) to simulate the surface convection and stratification of HD 49933. In a local box, the code solves the full set of conservative hydrodynamical equations coupled to an accurate treatment of the radiative t ...
The central star of the planetary nebula PB 8: a Wolf-Rayet
... A considerable fraction of the central stars of planetary nebulæ (CSPNe) are hydrogen-deficient. As a rule, these CSPNe exhibit a chemical composition of helium, carbon, and oxygen with the majority showing Wolf-Rayet-like emission line spectra. These stars are classified as CSPNe of a spectral type ...
... A considerable fraction of the central stars of planetary nebulæ (CSPNe) are hydrogen-deficient. As a rule, these CSPNe exhibit a chemical composition of helium, carbon, and oxygen with the majority showing Wolf-Rayet-like emission line spectra. These stars are classified as CSPNe of a spectral type ...
Stellar Relaxation Times
... derivation by Chandrasekhar gives ⎧ bmax v 2 ⎫ ⎧ bmax v 2 ⎫ v3 v3 ...
... derivation by Chandrasekhar gives ⎧ bmax v 2 ⎫ ⎧ bmax v 2 ⎫ v3 v3 ...
Taoist North Star Meditations (Fire Practice)
... Li session ends with rolling of the eyes as described above, except this time the energy is collected in the cauldron at the solar plexus. The Greatest Kan and Li can be performed in the morning directly after doing the Fusion of the Five Elements. Planets and the Stars Taoist Yoga seeks to connect ...
... Li session ends with rolling of the eyes as described above, except this time the energy is collected in the cauldron at the solar plexus. The Greatest Kan and Li can be performed in the morning directly after doing the Fusion of the Five Elements. Planets and the Stars Taoist Yoga seeks to connect ...
Lecture17
... A shrinking of 40 m per years would be sufficient Would keep Sun shining for 100 million years In the 19th century, that seemed long enough In the 21st century, we know that the Sun and the Earth are much older than 100 million years A new source of energy had to be understood in the ...
... A shrinking of 40 m per years would be sufficient Would keep Sun shining for 100 million years In the 19th century, that seemed long enough In the 21st century, we know that the Sun and the Earth are much older than 100 million years A new source of energy had to be understood in the ...
sections 4-6 instructor notes
... preferentially the most luminous objects of its type when it is limited by apparent magnitude, for example, the determination of MV for B5 V stars. That is known as Malmquist bias, for which suitable corrections exist. The presence of measuring errors in trigonometric parallaxes also makes their use ...
... preferentially the most luminous objects of its type when it is limited by apparent magnitude, for example, the determination of MV for B5 V stars. That is known as Malmquist bias, for which suitable corrections exist. The presence of measuring errors in trigonometric parallaxes also makes their use ...
L103 A NEW MILKY WAY DWARF SATELLITE IN CANES
... of the Milky Way. Together with the two dwarf irregulars (the Large and Small Magellanic Clouds), these make up all the known satellite galaxies of the Milky Way. The dSphs have such low surface brightness that they have often been found serendipitously. For example, while Sextans (Irwin et al. 1990 ...
... of the Milky Way. Together with the two dwarf irregulars (the Large and Small Magellanic Clouds), these make up all the known satellite galaxies of the Milky Way. The dSphs have such low surface brightness that they have often been found serendipitously. For example, while Sextans (Irwin et al. 1990 ...
Key paper.
... to vary as power laws. The exponent, 0.61, of the radial profile in disk temperature is obtained from a least-squares fit to the infrared spectral energy distribution; the radial density exponent15 is set at 7/ 4. Free parameters are disk mass, MD, and b. From model fits to our 1.3- and 2.7-mm flux ...
... to vary as power laws. The exponent, 0.61, of the radial profile in disk temperature is obtained from a least-squares fit to the infrared spectral energy distribution; the radial density exponent15 is set at 7/ 4. Free parameters are disk mass, MD, and b. From model fits to our 1.3- and 2.7-mm flux ...