High-precision abundances of elements in solar twin stars: Trends
... ance of Fe lines. Non-LTE effects are considered and taken into account for some of the elements. In addition, precise (σ ∼ stellar ages are obtained by interpolating between Yonsei-Yale isochrones in the log g-T eff diagram. Results. It is confirmed that the ratio between refractory and volatile el ...
... ance of Fe lines. Non-LTE effects are considered and taken into account for some of the elements. In addition, precise (σ ∼ stellar ages are obtained by interpolating between Yonsei-Yale isochrones in the log g-T eff diagram. Results. It is confirmed that the ratio between refractory and volatile el ...
Neutron Stars
... Figure: Mass-radius curve for HWW EoS configurations. The curve is parametrized by central density measured in gr/cm3 . At the extrema (max or min) the configuration becomes unstable/stable for increasing central density. ...
... Figure: Mass-radius curve for HWW EoS configurations. The curve is parametrized by central density measured in gr/cm3 . At the extrema (max or min) the configuration becomes unstable/stable for increasing central density. ...
Binarity in carbon-enhanced metal-poor stars
... these variations are comparable to the observational uncertainties in the case of BD +44-493. Radial velocity data for eight more stars have in the meantime been added (Hansen, Andersen & Nordtröm 2012, also see Andersen et al. in preparation). They find that two out of their sample of eight CEMP-n ...
... these variations are comparable to the observational uncertainties in the case of BD +44-493. Radial velocity data for eight more stars have in the meantime been added (Hansen, Andersen & Nordtröm 2012, also see Andersen et al. in preparation). They find that two out of their sample of eight CEMP-n ...
Notes on Stars
... Transmission curves for the currently most widely used Johnson UBV, Kron Cousins RI filter system, as reconstructed by Bessel (PASP, 1990). A G5V star (similar to the sun, but somewhat cooler) is overplotted for comparison. ...
... Transmission curves for the currently most widely used Johnson UBV, Kron Cousins RI filter system, as reconstructed by Bessel (PASP, 1990). A G5V star (similar to the sun, but somewhat cooler) is overplotted for comparison. ...
The Classification of Stellar Spectra
... early in the 1800’s, but it was not until late in the century that astronomers were able to routinely examine the spectra of stars in large numbers. Astronomers Angelo Secchi and E.C. Pickering were among the first to note that the stellar spectra could be divided into groups by the general appearan ...
... early in the 1800’s, but it was not until late in the century that astronomers were able to routinely examine the spectra of stars in large numbers. Astronomers Angelo Secchi and E.C. Pickering were among the first to note that the stellar spectra could be divided into groups by the general appearan ...
Introduction_to_pulsar_astronomy
... Radio scintillation studies led Hewish and Okoye (1964) to propose the existence of a compact radio source near the center of the nebula, with a steep spectrum. Pacini (1967) proposed the existence of a highly magnetized, rapidly spinning neutron star as the power source of the nebula. This would ra ...
... Radio scintillation studies led Hewish and Okoye (1964) to propose the existence of a compact radio source near the center of the nebula, with a steep spectrum. Pacini (1967) proposed the existence of a highly magnetized, rapidly spinning neutron star as the power source of the nebula. This would ra ...
Tycho Brahe
... • Otto Brahe’s brother Jörgen was married, but childless. He was not capable of producing a family of his own. • According to one account, Otto and Beate promised Jörgen their first son, but changed their minds. • Jörgen kidnapped Tycho after 1 year, while Beate was pregnant with their second. ...
... • Otto Brahe’s brother Jörgen was married, but childless. He was not capable of producing a family of his own. • According to one account, Otto and Beate promised Jörgen their first son, but changed their minds. • Jörgen kidnapped Tycho after 1 year, while Beate was pregnant with their second. ...
on the pms star hbc 498 and its associated nebulous stars1
... trapezium of young stellar objects (Cohen 1980; Cohen & Kuhi 1979) associated with a small dark cloud in the direction of L1641(see Figure 1). The separation between any two stars in the trapezium is of about 0.20 pc (at a distance of 460 pc). The 25 year old spectrophotometric (resolution ∆λ = 7 Å ...
... trapezium of young stellar objects (Cohen 1980; Cohen & Kuhi 1979) associated with a small dark cloud in the direction of L1641(see Figure 1). The separation between any two stars in the trapezium is of about 0.20 pc (at a distance of 460 pc). The 25 year old spectrophotometric (resolution ∆λ = 7 Å ...
Eye in the sky - Academy of Science of South Africa
... or light particles, it can collect in a given time. In addition, with telescopes and their associated cameras you can keep collecting the light for long times, equivalent to leaving a bucket out in the rain of faint light. Your eye and brain cannot do it. You see the world instantaneously (or, in so ...
... or light particles, it can collect in a given time. In addition, with telescopes and their associated cameras you can keep collecting the light for long times, equivalent to leaving a bucket out in the rain of faint light. Your eye and brain cannot do it. You see the world instantaneously (or, in so ...
THE N/O RATIO IN EARLY B-TYPE MAIN SEQUENCE STARS AS
... logC , logN , and logO for MS B-stars found in Ref. 14, together with recent estimates of the abundances of C, N, and O for the sun [15,16]. The latter were obtained using nonstationary hydrodynamic 3D models of the solar atmosphere. We note that the elemental abundances here and in the ...
... logC , logN , and logO for MS B-stars found in Ref. 14, together with recent estimates of the abundances of C, N, and O for the sun [15,16]. The latter were obtained using nonstationary hydrodynamic 3D models of the solar atmosphere. We note that the elemental abundances here and in the ...
The Classification of Stellar Spectra
... von Fraunhofer early in the 1800’s, but it was not until late in the century that astronomers were able to routinely examine the spectra of stars in large numbers. Astronomers Angelo Secchi and E.C. Pickering were among the first to note that the stellar spectra could be divided into groups by the g ...
... von Fraunhofer early in the 1800’s, but it was not until late in the century that astronomers were able to routinely examine the spectra of stars in large numbers. Astronomers Angelo Secchi and E.C. Pickering were among the first to note that the stellar spectra could be divided into groups by the g ...
2 Galaxy morphology and classification
... The spheroid is the smooth elliptical distribution of stars found in elliptical galaxies. It is composed primarily of an old, metal-poor, population of stars typically having ages „ 12 Gyr or more. The spheroid is thought to be among the first stellar components to form. The stellar halo is a di↵use ...
... The spheroid is the smooth elliptical distribution of stars found in elliptical galaxies. It is composed primarily of an old, metal-poor, population of stars typically having ages „ 12 Gyr or more. The spheroid is thought to be among the first stellar components to form. The stellar halo is a di↵use ...
Beyond simple depletion: phase behaviour of colloid–star polymer
... hard-sphere colloids and (smaller) random-coil polymers in a near-theta solvent for the latter. In this system, the only interaction is that of excluded volume between the colloids and between the colloids and polymers; the polymer coils can be treated, to a first approximation, as ideal, and therefo ...
... hard-sphere colloids and (smaller) random-coil polymers in a near-theta solvent for the latter. In this system, the only interaction is that of excluded volume between the colloids and between the colloids and polymers; the polymer coils can be treated, to a first approximation, as ideal, and therefo ...
Discovery of White Dwarfs—1 Oct • Adams’ discovery
... • How much smaller is Sirius B? • Apparent mag of Sirius A is −1.5 • Apparent mag of Sirius B is 8.7 ...
... • How much smaller is Sirius B? • Apparent mag of Sirius A is −1.5 • Apparent mag of Sirius B is 8.7 ...
Summary of dynamics of the regular heptagon: N =7
... only tile which is shared by both D and N = 7. For N = 14, the shared tile would be a scaled copy of N = 7 and in this case D and N= 14 would have identical webs and conjugate dynamics. On the left below is the first iteration of the web local to S[1] – showing the ‘swap domain and range’ algorithm ...
... only tile which is shared by both D and N = 7. For N = 14, the shared tile would be a scaled copy of N = 7 and in this case D and N= 14 would have identical webs and conjugate dynamics. On the left below is the first iteration of the web local to S[1] – showing the ‘swap domain and range’ algorithm ...
Protostellar/PMS Mass Infall Luminosity Problem
... Dunham et al. (2013) extended the c2D sample from 112 to 230 protostars, but 100 of the new sources lacks sub-mm detections, so their totoal luminosity is underestimated by a factor of 2.6 on average (could be up to 10). The low luminosity tail of the PLF is very uncertain ...
... Dunham et al. (2013) extended the c2D sample from 112 to 230 protostars, but 100 of the new sources lacks sub-mm detections, so their totoal luminosity is underestimated by a factor of 2.6 on average (could be up to 10). The low luminosity tail of the PLF is very uncertain ...
Cygnus (constellation)
Cygnus /ˈsɪɡnəs/ is a northern constellation lying on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan. The swan is one of the most recognizable constellations of the northern summer and autumn, it features a prominent asterism known as the Northern Cross (in contrast to the Southern Cross). Cygnus was among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.Cygnus contains Deneb, one of the brightest stars in the night sky and one corner of the Summer Triangle, as well as some notable X-ray sources and the giant stellar association of Cygnus OB2. One of the stars of this association, NML Cygni, is one of the largest stars currently known. The constellation is also home to Cygnus X-1, a distant X-ray binary containing a supergiant and unseen massive companion that was the first object widely held to be a black hole. Many star systems in Cygnus have known planets as a result of the Kepler Mission observing one patch of the sky, the patch is the area around Cygnus. In addition, most of the eastern part of Cygnus is dominated by the Hercules–Corona Borealis Great Wall, a giant galaxy filament that is the largest known structure in the observable universe; covering most of the northern sky.