the May 2017 Newsletter!
... very close, the star could quite easily be seen as double in a 6 inch telescope. Other double stars were Castor and Alpha Centauri. Both of the latter have recently opened up from a close approach as viewed from Earth – Castor closed up for about 30 years. (See footnote 1); the Alpha Centauri pair a ...
... very close, the star could quite easily be seen as double in a 6 inch telescope. Other double stars were Castor and Alpha Centauri. Both of the latter have recently opened up from a close approach as viewed from Earth – Castor closed up for about 30 years. (See footnote 1); the Alpha Centauri pair a ...
Notes on Photoionized Regions 1. Introduction 2. Hydrogen Nebulae
... The existence of the helium ionization zone also modifies the hydrogen ionization zone. This is for two reasons. One is that photons above 24.6 eV are absorbed by helium and so are not availa ...
... The existence of the helium ionization zone also modifies the hydrogen ionization zone. This is for two reasons. One is that photons above 24.6 eV are absorbed by helium and so are not availa ...
Stellar Evolution
... main-sequence star becomes a giant • When hydrogen fusion ceases in the core, the star will collapse inward – this causes the layer just outside the core to become so hot and dense so that hydrogen fusion will begin in this outer layer. • The energy produced by hydrogen fusion in this layer just out ...
... main-sequence star becomes a giant • When hydrogen fusion ceases in the core, the star will collapse inward – this causes the layer just outside the core to become so hot and dense so that hydrogen fusion will begin in this outer layer. • The energy produced by hydrogen fusion in this layer just out ...
Einstein
... • …are the leftover cores from supernova explosions. • If the core < 3 M, it will stop collapsing and be held up by neutron degeneracy pressure. • Neutron stars are very dense (1012 g/cm3 ) – 1.5 M with a diameter of 10 to 20 km ...
... • …are the leftover cores from supernova explosions. • If the core < 3 M, it will stop collapsing and be held up by neutron degeneracy pressure. • Neutron stars are very dense (1012 g/cm3 ) – 1.5 M with a diameter of 10 to 20 km ...
Star Facts - Dr. Noha MH Elnagdi
... of a star emits an absorption spectrum rather than a continuous spectrum. A absorption spectrum is produced when light from a hot solid or dense gas passes through a cooler gas (which is the atmospheric gases of the star in this case) ...
... of a star emits an absorption spectrum rather than a continuous spectrum. A absorption spectrum is produced when light from a hot solid or dense gas passes through a cooler gas (which is the atmospheric gases of the star in this case) ...
Lecture 10: The Hertzsprung
... We know the masses for a few of the stars on the H-R diagram. When we plot the masses of the stars, we see that the main sequence is actually a mass sequence. More massive stars on the main sequence are hotter, low mass stars are cooler. Why? This is one of the things our model of how stars work nee ...
... We know the masses for a few of the stars on the H-R diagram. When we plot the masses of the stars, we see that the main sequence is actually a mass sequence. More massive stars on the main sequence are hotter, low mass stars are cooler. Why? This is one of the things our model of how stars work nee ...
Orion - CSIC
... that make up Orion lie at very different distances from the Sun. Their resemblance to a human figure is a chance alignment. Viewed from another angle, they would not look anything like a hunter. To illustrate this, we can make a three-dimensional model of Orion's stars in space. Materials: Large stu ...
... that make up Orion lie at very different distances from the Sun. Their resemblance to a human figure is a chance alignment. Viewed from another angle, they would not look anything like a hunter. To illustrate this, we can make a three-dimensional model of Orion's stars in space. Materials: Large stu ...
Dark Matter Spiral Structure Basic Galaxy Morphology Disk Galaxy Rotation Curves:
... explode. The brightest (and bluest) of a galaxy’s stars will never be far from the spiral arm where they were born. ...
... explode. The brightest (and bluest) of a galaxy’s stars will never be far from the spiral arm where they were born. ...
review
... straight lines into dense gas such as the outer atmosphere of a star. • D.charged particles move at speeds faster than the speed of light in any medium. (A) ...
... straight lines into dense gas such as the outer atmosphere of a star. • D.charged particles move at speeds faster than the speed of light in any medium. (A) ...
The Big Dipper Constellation
... The Big Dipper What is a Constellation? From very early times, man has been fascinated by the stars. Early stargazers began naming stars. They also noticed patterns of stars that appeared night after night in the sky. These patterns or groupings of stars are called constellations. They also began to ...
... The Big Dipper What is a Constellation? From very early times, man has been fascinated by the stars. Early stargazers began naming stars. They also noticed patterns of stars that appeared night after night in the sky. These patterns or groupings of stars are called constellations. They also began to ...
Milky Way - Wayne Hu`s Tutorials
... • Due to projection of velocities along the line of sight and differential rotation, the highest velocity occurs at the closest approach to the galactic center or tangent point • Build up a rotation curve interior to the solar circle R < R0 • Rotation curve steeply rises in the interior R < 1kpc, co ...
... • Due to projection of velocities along the line of sight and differential rotation, the highest velocity occurs at the closest approach to the galactic center or tangent point • Build up a rotation curve interior to the solar circle R < R0 • Rotation curve steeply rises in the interior R < 1kpc, co ...
Formation of Massive Stars
... When the protostar reaches the ZAMS, it begins producing appreciable UV flux and (possibly) a strong wind modifying the surrounding conditions, structure, & chemistry At this stage the star ionizes its surroundings, giving rise to a small region of ionized gas, usually referred as the ultracompact H ...
... When the protostar reaches the ZAMS, it begins producing appreciable UV flux and (possibly) a strong wind modifying the surrounding conditions, structure, & chemistry At this stage the star ionizes its surroundings, giving rise to a small region of ionized gas, usually referred as the ultracompact H ...
12-1 MAIN-SEQUENCE STARS
... support and can fuse nearly all of their hydrogen fuel, they will remain on the main sequence for many times the present age of the universe. Medium-mass stars between about 0.4 and 4 solar masses, including the sun, become cool giants and fuse helium but cannot fuse carbon. Medium-mass stars lose m ...
... support and can fuse nearly all of their hydrogen fuel, they will remain on the main sequence for many times the present age of the universe. Medium-mass stars between about 0.4 and 4 solar masses, including the sun, become cool giants and fuse helium but cannot fuse carbon. Medium-mass stars lose m ...
ASTR 1120-001 Final Examination Phil Armitage, Bruce Ferguson
... If you measured the velocities of many galaxies, you would find that typically: (a) Galaxies (except very nearby ones) were moving away from you, with the most distant ones moving away the slowest (b) Galaxies are moving toward you, with the most distant ones approaching the most rapidly (c) Galaxie ...
... If you measured the velocities of many galaxies, you would find that typically: (a) Galaxies (except very nearby ones) were moving away from you, with the most distant ones moving away the slowest (b) Galaxies are moving toward you, with the most distant ones approaching the most rapidly (c) Galaxie ...
Measuring the masses of clusters
... Masses of clusters from x-ray gas: •! If we assume the cluster is in hydrostatic equilibrium, #=density of the gas, P=pressure ...
... Masses of clusters from x-ray gas: •! If we assume the cluster is in hydrostatic equilibrium, #=density of the gas, P=pressure ...
1” “Sky-Notes” of the Open University Astronomy Club. April 2006. 1
... NGC4631 (9.7) sg and NG4656 (10.4) pc. are a fine example of a pair of interacting galaxies, both edge-on to our view, located mid-way between Cor Coroli and the Coma star cluster. One end of NGC4656 has a distinct hook which may be glimpsed in 8" telescopes under good seeing conditions. NGC4736 (M9 ...
... NGC4631 (9.7) sg and NG4656 (10.4) pc. are a fine example of a pair of interacting galaxies, both edge-on to our view, located mid-way between Cor Coroli and the Coma star cluster. One end of NGC4656 has a distinct hook which may be glimpsed in 8" telescopes under good seeing conditions. NGC4736 (M9 ...
Deducing Temperatures and Luminosities of Stars
... – Absolute magnitude of sun ≈ +5 (pretty faint) ...
... – Absolute magnitude of sun ≈ +5 (pretty faint) ...
The Origin of the Elements - Indiana University Astronomy
... our universe be if only very large stars formed? Only very small stars? ...
... our universe be if only very large stars formed? Only very small stars? ...
Whiteq
... The densities of white dwarves are, of course, very high. Sirius B has a density of about 125,000 g/cm3. The densest may be as much as 10,000 times denser than this. The most dense materials on earth are only about 20 g/cm3. This is why the idea was initially regarded with skepticism. These densitie ...
... The densities of white dwarves are, of course, very high. Sirius B has a density of about 125,000 g/cm3. The densest may be as much as 10,000 times denser than this. The most dense materials on earth are only about 20 g/cm3. This is why the idea was initially regarded with skepticism. These densitie ...
ppt - Astronomy & Physics
... So net result is conversion of 4 protons into Helium nucleus. The mass of the Helium nucleus is less than the mass of the 4 protons, and this mass is converted into energy, which powers the Sun (and other stars) ...
... So net result is conversion of 4 protons into Helium nucleus. The mass of the Helium nucleus is less than the mass of the 4 protons, and this mass is converted into energy, which powers the Sun (and other stars) ...
answer key
... main sequence, the cooler K and M type stars have less mass than our Sun. The small energy release per unit time leads to low luminosities for these stars, so they have very long lifetimes. Many of the K and M type stars now seen in the sky will shine on for at least another trillion years. (Yeah. T ...
... main sequence, the cooler K and M type stars have less mass than our Sun. The small energy release per unit time leads to low luminosities for these stars, so they have very long lifetimes. Many of the K and M type stars now seen in the sky will shine on for at least another trillion years. (Yeah. T ...
Chapter 29: Stars - Mr. Pelton Science
... • Extends for several million kilometers from the outside edge of the chromosphere. • Temperature: 1 Million – 2 Million K ...
... • Extends for several million kilometers from the outside edge of the chromosphere. • Temperature: 1 Million – 2 Million K ...
Absolute magnitude
... to jump to a higher energy level. ▪ The photon’s energy must be equal to the energy difference between the two levels. ...
... to jump to a higher energy level. ▪ The photon’s energy must be equal to the energy difference between the two levels. ...
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.