April 10th
... • Carbon and silicon atoms form grains, which are pushed outward by radiation • Red Giant loses material (as much as 10-4 solar masses per year) ...
... • Carbon and silicon atoms form grains, which are pushed outward by radiation • Red Giant loses material (as much as 10-4 solar masses per year) ...
The magnitude scale, parallax, the parsec, and Cepheid distances
... • To do this we need a property that does not vary with distance which is correlated with the absolute magnitude, e.g: – Cepheid variables (discovered by HenrieMa LeaviM (1912) • The Period-‐Luminosity r ...
... • To do this we need a property that does not vary with distance which is correlated with the absolute magnitude, e.g: – Cepheid variables (discovered by HenrieMa LeaviM (1912) • The Period-‐Luminosity r ...
Chapter 16
... • Beyond the Milky Way are millions of other galaxies • Some galaxies are spiral like the Milky Way while others are egg-shaped or completely irregular in appearance • Besides shape, galaxies vary greatly in the star, gas, and dust content and some are more “active” than others • Galaxies tend to cl ...
... • Beyond the Milky Way are millions of other galaxies • Some galaxies are spiral like the Milky Way while others are egg-shaped or completely irregular in appearance • Besides shape, galaxies vary greatly in the star, gas, and dust content and some are more “active” than others • Galaxies tend to cl ...
Star Spectra - Renton School District
... Gizmo Warm-up The interior of a star produces a continuous spectrum of light, like a rainbow. Cooler gases in the outer layers of the star absorb certain wavelengths of light, causing dark lines to appear in the spectrum. The resulting absorption spectrum can tell astronomers a great deal about the ...
... Gizmo Warm-up The interior of a star produces a continuous spectrum of light, like a rainbow. Cooler gases in the outer layers of the star absorb certain wavelengths of light, causing dark lines to appear in the spectrum. The resulting absorption spectrum can tell astronomers a great deal about the ...
Major Themes of “ The First Stars ”
... Approach: Hydrosims of gas physics in early cosmological halos Key Results: High mass range (~30 - 300) for limiting Z = 0 case. Formation of first low-mass stars depends on prior ionization and/or metal enrichment metals, dust, CMB, other factors (?) How did the first and second stars form, and wha ...
... Approach: Hydrosims of gas physics in early cosmological halos Key Results: High mass range (~30 - 300) for limiting Z = 0 case. Formation of first low-mass stars depends on prior ionization and/or metal enrichment metals, dust, CMB, other factors (?) How did the first and second stars form, and wha ...
White Dwarf
... •Helium is burning to Carbon in a shell around the Carbon core while H-to-He burning occurs in an outer ...
... •Helium is burning to Carbon in a shell around the Carbon core while H-to-He burning occurs in an outer ...
Observations and Theoretical Models of Subdwarfs
... spectra of these stars demonstrated abnormally faint metallic lines for their spectral class. Four years later, Gerard Kuiper renamed them “subdwarfs” after observing that these intermediate stars had less in common with the degenerate white dwarfs than they did with main sequence dwarf stars [1]. S ...
... spectra of these stars demonstrated abnormally faint metallic lines for their spectral class. Four years later, Gerard Kuiper renamed them “subdwarfs” after observing that these intermediate stars had less in common with the degenerate white dwarfs than they did with main sequence dwarf stars [1]. S ...
Astro 10B Study Questions for Each Chapter
... Which is larger: the Local Group or the Local Cluster? How are galaxies, groups and clusters distributed through space? Which type of clusters contain the most giant elliptical galaxies? Where would you find a galaxy which is the result of several mergers? What happens when galaxies collide? How wou ...
... Which is larger: the Local Group or the Local Cluster? How are galaxies, groups and clusters distributed through space? Which type of clusters contain the most giant elliptical galaxies? Where would you find a galaxy which is the result of several mergers? What happens when galaxies collide? How wou ...
Ch17_lecture
... • Beyond the Milky Way are billions of other galaxies • Some galaxies are spiral like the Milky Way while others are egg-shaped or completely irregular in appearance • Besides shape, galaxies vary greatly in the star, gas, and dust content and some are more “active” than others • Galaxies tend to cl ...
... • Beyond the Milky Way are billions of other galaxies • Some galaxies are spiral like the Milky Way while others are egg-shaped or completely irregular in appearance • Besides shape, galaxies vary greatly in the star, gas, and dust content and some are more “active” than others • Galaxies tend to cl ...
The (Stellar) Parallax View
... Many new astronomers marvel at the vast distances separating astronomical objects, but after a while wonder how do we know for sure how big these distances are. After all we cannot send a probe to the star Altair to confirm that it is 17 light years away. So how do we measure the distances to the st ...
... Many new astronomers marvel at the vast distances separating astronomical objects, but after a while wonder how do we know for sure how big these distances are. After all we cannot send a probe to the star Altair to confirm that it is 17 light years away. So how do we measure the distances to the st ...
Chapter 17 Galaxies Galaxies Early Observations
... • Beyond the Milky Way are billions of other galaxies • Some galaxies are spiral like the Milky Way while others are egg-shaped or completely irregular in appearance • Besides shape, galaxies vary greatly in the star, gas, and dust content and some are more “active” than others • Galaxies tend to cl ...
... • Beyond the Milky Way are billions of other galaxies • Some galaxies are spiral like the Milky Way while others are egg-shaped or completely irregular in appearance • Besides shape, galaxies vary greatly in the star, gas, and dust content and some are more “active” than others • Galaxies tend to cl ...
The central star of the planetary nebula PB 8: a Wolf-Rayet
... are classified as CSPNe of a spectral type [WC]. We perform a spectral analysis of CSPN PB 8 with the Potsdam Wolf-Rayet (PoWR) models for expanding atmospheres. The source PB 8 displays wind-broadened emission lines from strong mass loss. Most strikingly, we find that its surface composition is hyd ...
... are classified as CSPNe of a spectral type [WC]. We perform a spectral analysis of CSPN PB 8 with the Potsdam Wolf-Rayet (PoWR) models for expanding atmospheres. The source PB 8 displays wind-broadened emission lines from strong mass loss. Most strikingly, we find that its surface composition is hyd ...
Encyclopedia of Optical Engineering Stellar Evolution
... star is its mass. The ‘‘weight’’ of a star must be balanced by internal pressure from rapidly moving particles and energetic photons. Under these extreme conditions, nuclear reactions occur. For higher-mass stars, greater pressures and temperatures are required to balance the gravity. These stars ha ...
... star is its mass. The ‘‘weight’’ of a star must be balanced by internal pressure from rapidly moving particles and energetic photons. Under these extreme conditions, nuclear reactions occur. For higher-mass stars, greater pressures and temperatures are required to balance the gravity. These stars ha ...
supernova - Michigan State University
... Contribution of Massive Stars to Galactic Nucleosynthesis Displayed is the overproduction factor X/Xsolar This is the fraction of matter in the Galaxy that had to be processed through the scenario (massive stars here) to account for todays observed solar abundances. To explain the origin of the ele ...
... Contribution of Massive Stars to Galactic Nucleosynthesis Displayed is the overproduction factor X/Xsolar This is the fraction of matter in the Galaxy that had to be processed through the scenario (massive stars here) to account for todays observed solar abundances. To explain the origin of the ele ...
Stars 3
... Nebula. These include wisp-like structures that move outward away from the pulsar at half the speed of light, as well as a mysterious “halo” which remains stationary, but grows brighter then fainter over time. Also seen are the effects of two polar jets that move out along the rotation axis of the p ...
... Nebula. These include wisp-like structures that move outward away from the pulsar at half the speed of light, as well as a mysterious “halo” which remains stationary, but grows brighter then fainter over time. Also seen are the effects of two polar jets that move out along the rotation axis of the p ...
Stellar Evolution
... fraction of the centers of the stars that are convective gets larger with larger masses. In the highest mass stars, the convection prevents the cores from becoming structured – there is continual mixing so any density variations are wiped out by convection. In low mass stars the cores are thought to ...
... fraction of the centers of the stars that are convective gets larger with larger masses. In the highest mass stars, the convection prevents the cores from becoming structured – there is continual mixing so any density variations are wiped out by convection. In low mass stars the cores are thought to ...
printer-friendly version of benchmark
... mass. Stars with greater mass have a greater gravitational attraction – causing the core temperature to be greater, which in turn increases the rate of nuclear fusion and decreases the star’s time on the main sequence. Likewise, lower mass stars have lesser rates of fusion and greater amounts of tim ...
... mass. Stars with greater mass have a greater gravitational attraction – causing the core temperature to be greater, which in turn increases the rate of nuclear fusion and decreases the star’s time on the main sequence. Likewise, lower mass stars have lesser rates of fusion and greater amounts of tim ...
Planetarium Activity 1 Learning to measure brightness and Limiting
... 1. You will be shown five popular constellations (Ursa Major, Cassiopeia, Leo, Ursa Minor and Orion) fix their position in the sky when the lights are off so that its approximated location can be found as the lights brighten. Use dots to Sketch the constellations on your worksheet and connect the st ...
... 1. You will be shown five popular constellations (Ursa Major, Cassiopeia, Leo, Ursa Minor and Orion) fix their position in the sky when the lights are off so that its approximated location can be found as the lights brighten. Use dots to Sketch the constellations on your worksheet and connect the st ...
What is a Star - Optics Institute of Southern California
... star as the internal pressure gradient balances against the force of gravity. Another way of thinking about this is to imagine the star as a large number of nested thin spherical shells (sort of like an onion). The inward forces on each shell consist of the gravitational pull from all the shells ins ...
... star as the internal pressure gradient balances against the force of gravity. Another way of thinking about this is to imagine the star as a large number of nested thin spherical shells (sort of like an onion). The inward forces on each shell consist of the gravitational pull from all the shells ins ...
CHP 13
... 1. The lowest-mass stars cannot become giants because a. they do not contain helium. b. they rotate too slowly. c. they cannot heat their centers hot enough. d. they contain strong magnetic fields. e. they never use up their hydrogen. 2. A planetary nebula is a. the expelled outer envelope of a medi ...
... 1. The lowest-mass stars cannot become giants because a. they do not contain helium. b. they rotate too slowly. c. they cannot heat their centers hot enough. d. they contain strong magnetic fields. e. they never use up their hydrogen. 2. A planetary nebula is a. the expelled outer envelope of a medi ...
The Death of Stars
... 1. The lowest-mass stars cannot become giants because a. they do not contain helium. b. they rotate too slowly. c. they cannot heat their centers hot enough. d. they contain strong magnetic fields. e. they never use up their hydrogen. 2. A planetary nebula is a. the expelled outer envelope of a medi ...
... 1. The lowest-mass stars cannot become giants because a. they do not contain helium. b. they rotate too slowly. c. they cannot heat their centers hot enough. d. they contain strong magnetic fields. e. they never use up their hydrogen. 2. A planetary nebula is a. the expelled outer envelope of a medi ...
Birth, Age and the Future of the Universe
... Berne, and it is still an important research topic at ISSI. ...
... Berne, and it is still an important research topic at ISSI. ...
Evolutionary properties of galaxies and mass assembly up
... locally is already present at z ~ 1.2, the environmental dependency of the LF shape at high redshift appears to be different from what is seen at low redshift. Is this difference due to an increase with cosmic time of the number of faint red galaxies, developing a steep slope of LF of early type gal ...
... locally is already present at z ~ 1.2, the environmental dependency of the LF shape at high redshift appears to be different from what is seen at low redshift. Is this difference due to an increase with cosmic time of the number of faint red galaxies, developing a steep slope of LF of early type gal ...
H II region
An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.