Galaxies and Stars
... Galaxy – a large system of stars held together by the same gravitational pull and separated from other large systems. ...
... Galaxy – a large system of stars held together by the same gravitational pull and separated from other large systems. ...
Galaxy
... together by gravity Found mainly in the galaxy’s disk and spiral arms More than 1000 have been discovered in the Milky Way Young stars that recently formed from nebulosity Jewel Box open cluster (NGC 4755) ...
... together by gravity Found mainly in the galaxy’s disk and spiral arms More than 1000 have been discovered in the Milky Way Young stars that recently formed from nebulosity Jewel Box open cluster (NGC 4755) ...
Summary Of the Structure of the Milky Way
... • The Distribution of stars can reveal part of the disk-like nature of the Milky Way galaxy, but are not “deep” enough probes to fully reveal the structure of the Milky Way. • Open clusters can define the thickness of the Milky Way’s thin disk where star formation is active. • Globular clusters allo ...
... • The Distribution of stars can reveal part of the disk-like nature of the Milky Way galaxy, but are not “deep” enough probes to fully reveal the structure of the Milky Way. • Open clusters can define the thickness of the Milky Way’s thin disk where star formation is active. • Globular clusters allo ...
April 1st
... • These lumps tend to condense into stars • That is why stars tend to be found in clusters ...
... • These lumps tend to condense into stars • That is why stars tend to be found in clusters ...
Quantum Well Electron Gain Structures and Infrared
... • More: we see major LBV line variability (factors of ~5-6 variation in EW in 1 year) implies that one star is dominant source of ionizing radiation • Thus, even if it is a binary, probable q>1 and mass limit >> 75 M0 • (And … something BIGGER made a neutron star ...
... • More: we see major LBV line variability (factors of ~5-6 variation in EW in 1 year) implies that one star is dominant source of ionizing radiation • Thus, even if it is a binary, probable q>1 and mass limit >> 75 M0 • (And … something BIGGER made a neutron star ...
guide to orion 3-d flythrough
... 100,000 times that of the Sun, provides the energy that creates the nebula as we see it. It produces a flood of ultraviolet light that ionizes the surface layers of the molecular cloud and causes them to glow. This illumination makes it possible to study many features that otherwise would be invisib ...
... 100,000 times that of the Sun, provides the energy that creates the nebula as we see it. It produces a flood of ultraviolet light that ionizes the surface layers of the molecular cloud and causes them to glow. This illumination makes it possible to study many features that otherwise would be invisib ...
ASTRONOMY 313
... hydrogen at 1215 Å (corresponding to a transition between the first and second energy levels of neutral hydrogen atoms) is observed in the optical spectrum of HS1946+7658 to be in emission at a wavelength of 4884.3 Å, in the blue-green region. a. ...
... hydrogen at 1215 Å (corresponding to a transition between the first and second energy levels of neutral hydrogen atoms) is observed in the optical spectrum of HS1946+7658 to be in emission at a wavelength of 4884.3 Å, in the blue-green region. a. ...
PH109 Exploring the Uiverse, Test #4, Spring, 1999
... 33. How long does it takes the Sun to travel around the center of the Galaxy a) one billion years, b) 250 million years, c) one million years, d) 5 billion years 34. Galaxies which show no flat structural feature, but just a smooth apparently three-dimensional luminosity structure, are called a) bor ...
... 33. How long does it takes the Sun to travel around the center of the Galaxy a) one billion years, b) 250 million years, c) one million years, d) 5 billion years 34. Galaxies which show no flat structural feature, but just a smooth apparently three-dimensional luminosity structure, are called a) bor ...
November - LVAstronomy.com
... monthly summary. We also accept digital imaging. Visual astronomy depends on what’s seen through the eyepiece. Not only does it satisfy an innate curiosity, but it allows the visual observer to discover the beauty and the wonderment of the night sky. Before photography, all observations depended on ...
... monthly summary. We also accept digital imaging. Visual astronomy depends on what’s seen through the eyepiece. Not only does it satisfy an innate curiosity, but it allows the visual observer to discover the beauty and the wonderment of the night sky. Before photography, all observations depended on ...
Microsoft Power Point version
... What is the Hertzsprung-Russell (HR) diagram? • It is the most important classification tool in stellar astronomy. Stars are located on the HR diagram by their surface temperature (or spectral type) along the horizontal axis and their luminosity along the vertical axis. Temperature decreases from le ...
... What is the Hertzsprung-Russell (HR) diagram? • It is the most important classification tool in stellar astronomy. Stars are located on the HR diagram by their surface temperature (or spectral type) along the horizontal axis and their luminosity along the vertical axis. Temperature decreases from le ...
16. Properties of Stars
... What is the Hertzsprung-Russell (HR) diagram? • It is the most important classification tool in stellar astronomy. Stars are located on the HR diagram by their surface temperature (or spectral type) along the horizontal axis and their luminosity along the vertical axis. Temperature decreases from le ...
... What is the Hertzsprung-Russell (HR) diagram? • It is the most important classification tool in stellar astronomy. Stars are located on the HR diagram by their surface temperature (or spectral type) along the horizontal axis and their luminosity along the vertical axis. Temperature decreases from le ...
Lecture 17 Review
... Short-lived massive stars, 20 to 40 solar masses , live only a few million years but we see them. The process for star formation is thought to involve a large cloud of gas, say 1035 kg or 105 solar masses, cold enough so that gravity can overcome random thermal motion. The cloud contracts gravitatio ...
... Short-lived massive stars, 20 to 40 solar masses , live only a few million years but we see them. The process for star formation is thought to involve a large cloud of gas, say 1035 kg or 105 solar masses, cold enough so that gravity can overcome random thermal motion. The cloud contracts gravitatio ...
V - ESO
... This is generally assumed to be the reason why, though star formation proceeds on a typical scale comparable to the size of a giant molecular cloud (~80 pc, Efremov 1995, AJ 100, 2757), Milky Way massive clusters tend to be much smaller. Image taken from class by James Schombert, University of Oreg ...
... This is generally assumed to be the reason why, though star formation proceeds on a typical scale comparable to the size of a giant molecular cloud (~80 pc, Efremov 1995, AJ 100, 2757), Milky Way massive clusters tend to be much smaller. Image taken from class by James Schombert, University of Oreg ...
galaxy - 106Thursday130-430
... • It is not the ordinary matter of stars, gas , dust, and planets. • The visible matter is surrounded by a halo of this dark matter containing the major portion of the total galaxy mass and extending very far beyond the visible matter. Some indirect means suggest that the dark matter halo may extend ...
... • It is not the ordinary matter of stars, gas , dust, and planets. • The visible matter is surrounded by a halo of this dark matter containing the major portion of the total galaxy mass and extending very far beyond the visible matter. Some indirect means suggest that the dark matter halo may extend ...
ASTRO 1050 The Structure of the Milky Way Galaxy
... A way to look at patterns in a set of data is a histogram. A histogram is a bar graph that shows the number of objects that have a certain property. A common type of histogram is the one that shows your grade compared to others in a class. Your instructor will show you how to make a histogram. For c ...
... A way to look at patterns in a set of data is a histogram. A histogram is a bar graph that shows the number of objects that have a certain property. A common type of histogram is the one that shows your grade compared to others in a class. Your instructor will show you how to make a histogram. For c ...
Astro 10 Practice Test 3
... b. The helium in their cores has all been used up, which means they’ve started buring hydrogen for the first time. c. They have been ejected from the cluster by gravitational encounters with other stars. d. They’ve run out of hydrogen to burn in their cores, and have evolved into red giants. ...
... b. The helium in their cores has all been used up, which means they’ve started buring hydrogen for the first time. c. They have been ejected from the cluster by gravitational encounters with other stars. d. They’ve run out of hydrogen to burn in their cores, and have evolved into red giants. ...
The Milky Way`s Restless Swarms of Stars
... stars (see main text) and whittles away its mass. Clusters are threatened from outside, too; our Milky Way snacks on them like finger foods. Over time, the galaxy can shred a compact cluster into ghostly streams of stars. “Once a globular cluster forms, it immediately starts dying,” says astronomer ...
... stars (see main text) and whittles away its mass. Clusters are threatened from outside, too; our Milky Way snacks on them like finger foods. Over time, the galaxy can shred a compact cluster into ghostly streams of stars. “Once a globular cluster forms, it immediately starts dying,” says astronomer ...
Introduction to Galaxies and Cosmology Exercises 2
... b) What is the mass of the black hole if one assume it to radiate at 10% of its Eddinton luminosity? c) What is the Schwarzschild radius of the black hole? 9. (Challenging) A quasar emits two radiating clouds in our general direction at 13/14 the speed of light. They are first observed when they app ...
... b) What is the mass of the black hole if one assume it to radiate at 10% of its Eddinton luminosity? c) What is the Schwarzschild radius of the black hole? 9. (Challenging) A quasar emits two radiating clouds in our general direction at 13/14 the speed of light. They are first observed when they app ...
Classification and structure of galaxies
... Globular Clusters • millions to hundreds of millions of stars • old! 6 to 13 billion years • mostly red giants and dwarfs • stars are clumped closely together, especially near the center of the cluster (densely); stars don’t drift apart • surround our disk as a halo Image at http://hubblesite.org/n ...
... Globular Clusters • millions to hundreds of millions of stars • old! 6 to 13 billion years • mostly red giants and dwarfs • stars are clumped closely together, especially near the center of the cluster (densely); stars don’t drift apart • surround our disk as a halo Image at http://hubblesite.org/n ...
Background Information - Eu-Hou
... In order to plot a HR diagram, the temperature and luminosity of the stars need to be known. The simplest indication of a star’s temperature is its colour. A star’s colour is simply a measure of the amount of light from the star in one filter compared to another. The most common colour system is B-V ...
... In order to plot a HR diagram, the temperature and luminosity of the stars need to be known. The simplest indication of a star’s temperature is its colour. A star’s colour is simply a measure of the amount of light from the star in one filter compared to another. The most common colour system is B-V ...
Summary: Nuclear burning in stars
... • Spiral arms have higher density than space between arms • Excess gravitational attraction slows down gas, stars when they pass through spiral arm in course of their orbits. • Î spiral arms are a traffic jam ...
... • Spiral arms have higher density than space between arms • Excess gravitational attraction slows down gas, stars when they pass through spiral arm in course of their orbits. • Î spiral arms are a traffic jam ...
ASTR 200 : Lecture 15 Ensemble Properties of Stars
... Gas Cloud → Main Sequence → ??? • So, a large cloud (1000s to ~million solar masses) gets cold enough that many cores collapse into stars, giving a cluster • Each star clears gas disk away, but the cluster as a whole also blows out all the remaining interstellar gas, shutting down star formation • ...
... Gas Cloud → Main Sequence → ??? • So, a large cloud (1000s to ~million solar masses) gets cold enough that many cores collapse into stars, giving a cluster • Each star clears gas disk away, but the cluster as a whole also blows out all the remaining interstellar gas, shutting down star formation • ...
Document
... •Tried to estimate Rayleigh scattering due to ISM gas but determined it to be insignificant (because most obscuration is due to ISM dust absorption which has a smaller dependence) ...
... •Tried to estimate Rayleigh scattering due to ISM gas but determined it to be insignificant (because most obscuration is due to ISM dust absorption which has a smaller dependence) ...
Open cluster
An open cluster, also known as galactic cluster, is a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way Galaxy, and many more are thought to exist. They are loosely bound by mutual gravitational attraction and become disrupted by close encounters with other clusters and clouds of gas as they orbit the galactic center, resulting in a migration to the main body of the galaxy as well as a loss of cluster members through internal close encounters. Open clusters generally survive for a few hundred million years, with the most massive ones surviving for a few billion years. In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for longer. Open clusters have been found only in spiral and irregular galaxies, in which active star formation is occurring.Young open clusters may still be contained within the molecular cloud from which they formed, illuminating it to create an H II region. Over time, radiation pressure from the cluster will disperse the molecular cloud. Typically, about 10% of the mass of a gas cloud will coalesce into stars before radiation pressure drives the rest of the gas away.Open clusters are key objects in the study of stellar evolution. Because the cluster members are of similar age and chemical composition, their properties (such as distance, age, metallicity and extinction) are more easily determined than they are for isolated stars. A number of open clusters, such as the Pleiades, Hyades or the Alpha Persei Cluster are visible with the naked eye. Some others, such as the Double Cluster, are barely perceptible without instruments, while many more can be seen using binoculars or telescopes. The Wild Duck Cluster, M11, is an example.