Luminosity, Flux and Magnitudes Outline
... All objects have internal energy which is manifested by the microscopic motions of particles. There is a continuum of energy levels associated with this motion. If the object is in thermal equilibrium then it can be characterized by a single quantity, it’s temperature. An object in thermal equilibri ...
... All objects have internal energy which is manifested by the microscopic motions of particles. There is a continuum of energy levels associated with this motion. If the object is in thermal equilibrium then it can be characterized by a single quantity, it’s temperature. An object in thermal equilibri ...
The Classification of Stellar Spectra
... Background: The History And Nature Of Spectral Classification Patterns of absorption lines were first observed in the spectrum of the sun by the German physicist Joseph von Fraunhofer early in the 1800’s, but it was not until late in the century that astronomers were able to routinely examine the sp ...
... Background: The History And Nature Of Spectral Classification Patterns of absorption lines were first observed in the spectrum of the sun by the German physicist Joseph von Fraunhofer early in the 1800’s, but it was not until late in the century that astronomers were able to routinely examine the sp ...
Title: Binary interaction dominates the evolution of massive stars
... pairs (π = -0.55 ± 0.2) and a uniform distribution of the mass ratio (κ = -0.1 ± 0.6) for binaries with periods up to about nine years. Comparison of the intrinsic, simulated and observed cumulative distributions of the orbital parameters shows that observational biases are mostly restricted to the ...
... pairs (π = -0.55 ± 0.2) and a uniform distribution of the mass ratio (κ = -0.1 ± 0.6) for binaries with periods up to about nine years. Comparison of the intrinsic, simulated and observed cumulative distributions of the orbital parameters shows that observational biases are mostly restricted to the ...
The DBV stars: Progress and problems
... ’whitedwarfs. There are at least two possible progenitors of DB white dwarfs: the PG 1159 stars and the interacting binary white dwarfs. Dehner & Kawaler (1995) show the seismological helium profile of PG 1159-035 can evolve into something similar to what Bradley & Winget (1994) derive for GD 358, b ...
... ’whitedwarfs. There are at least two possible progenitors of DB white dwarfs: the PG 1159 stars and the interacting binary white dwarfs. Dehner & Kawaler (1995) show the seismological helium profile of PG 1159-035 can evolve into something similar to what Bradley & Winget (1994) derive for GD 358, b ...
SkyWatcher2017.5 1.3 Mb - Boise Astronomical Society
... luminosity distance of DL = 749 mega-parsecs may be calculated from z. It is also one of the most luminous quasars known, with an absolute magnitude of −26.7, meaning that if it were only as distant as Pollux it would appear nearly as bright in the sky as the Sun. Since the sun's absolute magnitude ...
... luminosity distance of DL = 749 mega-parsecs may be calculated from z. It is also one of the most luminous quasars known, with an absolute magnitude of −26.7, meaning that if it were only as distant as Pollux it would appear nearly as bright in the sky as the Sun. Since the sun's absolute magnitude ...
has occurred over the past 14 billion years COSMIC DOWNSIZING
... coarse, the galaxies have a bloblike appearance [see illustration above]. They are also relatively rare — even after many hours of exposure, few sources appeared on each SCUBA image — but ...
... coarse, the galaxies have a bloblike appearance [see illustration above]. They are also relatively rare — even after many hours of exposure, few sources appeared on each SCUBA image — but ...
don_lamb - New Views of the Universe
... Dominant timescale is set by jet propagation through collapsing core (~10-20 s) ...
... Dominant timescale is set by jet propagation through collapsing core (~10-20 s) ...
m V
... • Size 0.05 to 1 pc • Mass 0.2 to 60 M⊙ • Often seen against a bright HII background • Globules may be individual proto-stars condensing from a dense molecular cloud ...
... • Size 0.05 to 1 pc • Mass 0.2 to 60 M⊙ • Often seen against a bright HII background • Globules may be individual proto-stars condensing from a dense molecular cloud ...
THE DAWN OF X-RAY ASTRONOMY
... et al., 1965).7 Thus the source had to be a visible star and not a diffused nebulosity. This led to the sophisticated measurement of the location of Sco X–1 by an AS&E-MIT group led by Herbert Gursky (Gursky et al., 1966),8 with sufficient precision to enable its identification with a 13th magnitude ...
... et al., 1965).7 Thus the source had to be a visible star and not a diffused nebulosity. This led to the sophisticated measurement of the location of Sco X–1 by an AS&E-MIT group led by Herbert Gursky (Gursky et al., 1966),8 with sufficient precision to enable its identification with a 13th magnitude ...
The Galactic evolution of phosphorus
... Fig. 2. [P/Fe] as a function of the metallicity, [Fe/H]. The dimension of the symbols reflects the average line-to-line scatter of 0.045 dex. The error bars are the sum under quadrature of the uncertainties of P (the linear sum of line-to-line scatter and the systematic uncertainty) and of Fe, the l ...
... Fig. 2. [P/Fe] as a function of the metallicity, [Fe/H]. The dimension of the symbols reflects the average line-to-line scatter of 0.045 dex. The error bars are the sum under quadrature of the uncertainties of P (the linear sum of line-to-line scatter and the systematic uncertainty) and of Fe, the l ...
The role of black holes in galaxy formation and evolution
... dominant (cD) galaxies of cool-core clusters72,73. Their activity pattern differs from the erratic behaviour of quasars and is closer to a constant string of minor outbursts. In many low-accretion-rate AGN, the gas surrounding the black hole is not dense enough to radiate efficiently, and nearly all ...
... dominant (cD) galaxies of cool-core clusters72,73. Their activity pattern differs from the erratic behaviour of quasars and is closer to a constant string of minor outbursts. In many low-accretion-rate AGN, the gas surrounding the black hole is not dense enough to radiate efficiently, and nearly all ...
STELLAR AGE VERSUS MASS OF EARLY
... performed visually by allowing age steps of 0.05 dex. The age range was then kept fixed for the other colors (middle and bottom panel). We see from the top panel of Fig. 2 that the SSP of HPL07 exceeds the observed color range at intermediate ages. This is no surprise, though: since the reddest colo ...
... performed visually by allowing age steps of 0.05 dex. The age range was then kept fixed for the other colors (middle and bottom panel). We see from the top panel of Fig. 2 that the SSP of HPL07 exceeds the observed color range at intermediate ages. This is no surprise, though: since the reddest colo ...
Stellar radii from long-baseline interferometry
... it one of the fastest moving stars in terms of apparent displacement. Although some of this motion comes from the proximity of 61 Cyg to us, the pair is also moving fast into space relative to the Sun, at 108 km/s, indicating that 61 Cyg is not a member of the thin disk of our Galaxy. The proximity ...
... it one of the fastest moving stars in terms of apparent displacement. Although some of this motion comes from the proximity of 61 Cyg to us, the pair is also moving fast into space relative to the Sun, at 108 km/s, indicating that 61 Cyg is not a member of the thin disk of our Galaxy. The proximity ...
SherwoodWA_1973redux - Edinburgh Research Archive
... The nuclear bulge and the dust pattern are ...
... The nuclear bulge and the dust pattern are ...
Life Histories Of Some Stars
... all? Describe the shape of the graph? Is it a straight line? A curve? 5. Give each group the list of stars attached and the HR diagram attached. Instead of height and weight, the information is in Luminosity (compared to sun) and Surface Temperature (in K). The chart also gives the star’s current st ...
... all? Describe the shape of the graph? Is it a straight line? A curve? 5. Give each group the list of stars attached and the HR diagram attached. Instead of height and weight, the information is in Luminosity (compared to sun) and Surface Temperature (in K). The chart also gives the star’s current st ...
Stellarium User Guide - Skolekonsulenterne.dk
... Stellarium may be used as an educational tool for teaching about the night sky, as an observational aide for amateur astronomers wishing to plan a night’s observing, or simply as a curiosity (it’s fun!). Because of the high quality of the graphics that Stellarium produces, it is used in some real pl ...
... Stellarium may be used as an educational tool for teaching about the night sky, as an observational aide for amateur astronomers wishing to plan a night’s observing, or simply as a curiosity (it’s fun!). Because of the high quality of the graphics that Stellarium produces, it is used in some real pl ...
83-98
... DL Cas, BM Per, TX Cyg, X Cyg, CK Sct and UZ Sct using high-dispersion spectra and fine analysis. However, for X Cyg the estimate of HP is higher than the one derived by LL by 0.18 dex which is surprising. The differences in phases can partly account for the discrepancy. The observations of HP were ...
... DL Cas, BM Per, TX Cyg, X Cyg, CK Sct and UZ Sct using high-dispersion spectra and fine analysis. However, for X Cyg the estimate of HP is higher than the one derived by LL by 0.18 dex which is surprising. The differences in phases can partly account for the discrepancy. The observations of HP were ...
Stellarium – a valuable resource for teaching astronomy in the
... the cursor moves, the view of the sky from that point on the earth’s surface is displayed. If the cursor is moved horizontally a point is reached where the sun sets and it becomes dark – this is the terminator – the dividing line between day and night. If the date is set to the vernal equinox, i.e. ...
... the cursor moves, the view of the sky from that point on the earth’s surface is displayed. If the cursor is moved horizontally a point is reached where the sun sets and it becomes dark – this is the terminator – the dividing line between day and night. If the date is set to the vernal equinox, i.e. ...
Perseus (constellation)
Perseus, named after the Greek mythological hero Perseus, is a constellation in the northern sky. It was one of 48 listed by the 2nd-century astronomer Ptolemy and among the 88 modern constellations defined by the International Astronomical Union (IAU). It is located in the northern celestial hemisphere near several other constellations named after legends surrounding Perseus, including Andromeda to the west and Cassiopeia to the north. Perseus is also bordered by Aries and Taurus to the south, Auriga to the east, Camelopardalis to the north, and Triangulum to the west.The galactic plane of the Milky Way passes through Perseus but is mostly obscured by molecular clouds. The constellation's brightest star is the yellow-white supergiant Alpha Persei (also called Mirfak), which shines at magnitude 1.79. It and many of the surrounding stars are members of an open cluster known as the Alpha Persei Cluster. The best-known star, however, is Algol (Beta Persei), linked with ominous legends because of its variability, which is noticeable to the naked eye. Rather than being an intrinsically variable star, it is an eclipsing binary. Other notable star systems in Perseus include X Persei, a binary system containing a neutron star, and GK Persei, a nova that peaked at magnitude 0.2 in 1901. The Double Cluster, comprising two open clusters quite near each other in the sky, was known to the ancient Chinese. The constellation gives its name to the Perseus Cluster (Abell 426), a massive galaxy cluster located 250 million light-years from Earth. It hosts the radiant of the annual Perseids meteor shower—one of the most prominent meteor showers in the sky.