![Problem set 2](http://s1.studyres.com/store/data/015131691_1-1fe8dca0e0c45f9f56ec3a5713002945-300x300.png)
Problem set 2
... The star Proxima Centauri, probably bound gravitationally to α Centauri (α Cen), is a small main-sequence star of mass 0.123 solar. Using the empirical scaling between the mass and luminosity from the textbook, and between mass and radius (you can assume it’s linear, R ∼ M), compute Proxima’s effect ...
... The star Proxima Centauri, probably bound gravitationally to α Centauri (α Cen), is a small main-sequence star of mass 0.123 solar. Using the empirical scaling between the mass and luminosity from the textbook, and between mass and radius (you can assume it’s linear, R ∼ M), compute Proxima’s effect ...
Sample exam 2
... 13. Suppose you are looking at the emission spectrum of gaseous helium. You dutifully write down the wavelengths of emission. You notice a power dial on the side of emission lamp and, just for fun, decide to turn up the power. The color of the helium lamp changes and you look through the spectroscop ...
... 13. Suppose you are looking at the emission spectrum of gaseous helium. You dutifully write down the wavelengths of emission. You notice a power dial on the side of emission lamp and, just for fun, decide to turn up the power. The color of the helium lamp changes and you look through the spectroscop ...
Classifying Spectra PDF version - the Home Page for Voyager2
... The spectral classes are specified by the letters O, B, A, F, G, K, M, L, T going hotter to colder. Each letter is subdivided by assigning a number 0 through 9 following the letter and going from hotter to colder. So B0 is colder than O9 and hotter than B1. Obviously not every type is shown. Origina ...
... The spectral classes are specified by the letters O, B, A, F, G, K, M, L, T going hotter to colder. Each letter is subdivided by assigning a number 0 through 9 following the letter and going from hotter to colder. So B0 is colder than O9 and hotter than B1. Obviously not every type is shown. Origina ...
The Lives of Stars
... The core will shrink and grow hocer, burning more Hydrogen. The increased oudlow of energy will push out the outer layers, which will cool and become red. The sun will become a “R ...
... The core will shrink and grow hocer, burning more Hydrogen. The increased oudlow of energy will push out the outer layers, which will cool and become red. The sun will become a “R ...
The life cycle of a star
... When a star nears the end of its life, it runs out of hydrogen and other fuels needed to produce energy Pressure decreases in the star so the star swells (gets bigger) and cools down (turns red) Stars equal to or smaller than the sun become red giants Stars much larger than the Sun become red ...
... When a star nears the end of its life, it runs out of hydrogen and other fuels needed to produce energy Pressure decreases in the star so the star swells (gets bigger) and cools down (turns red) Stars equal to or smaller than the sun become red giants Stars much larger than the Sun become red ...
The Hertzsprung-Russell diagram and the nature of stars
... At this point, we have learned a lot about stars: absolute magnitudes (luminosities), distances, temperatures, chemical composition, spectral type… Let’s put all the pieces together and learn something really profound about stars ...
... At this point, we have learned a lot about stars: absolute magnitudes (luminosities), distances, temperatures, chemical composition, spectral type… Let’s put all the pieces together and learn something really profound about stars ...
Great Astronomers of the 20th Century
... variable stars (after prototype d Cepheus) – Discovered a magnitude-period relationship-brighter stars had longer periods – All stars were essentially at the same distance ...
... variable stars (after prototype d Cepheus) – Discovered a magnitude-period relationship-brighter stars had longer periods – All stars were essentially at the same distance ...
AST101_lect_12
... Examples: Rigel, in Orion, and Spica, in Virgo. • A: Temperatures from 8000-10,000K. They appear white. Strong absorption lines of hydrogen. Examples: Vega, Altair, Sirius. • F: slightly hotter than the Sun. Absorption lines of metals appear. Procyon is an F star. • G: temperatures between 5000 and ...
... Examples: Rigel, in Orion, and Spica, in Virgo. • A: Temperatures from 8000-10,000K. They appear white. Strong absorption lines of hydrogen. Examples: Vega, Altair, Sirius. • F: slightly hotter than the Sun. Absorption lines of metals appear. Procyon is an F star. • G: temperatures between 5000 and ...
Astronomy 162 Lab 4: Stars
... properties you are actually trying to compare. Observational Astronomers tend to use an HR Diagram that plots Spectral Class (which is directly related to temperature) on the x-axis against Absolute Magnitude on the y-axis. From this diagram, astronomers can study the relationship between temperatu ...
... properties you are actually trying to compare. Observational Astronomers tend to use an HR Diagram that plots Spectral Class (which is directly related to temperature) on the x-axis against Absolute Magnitude on the y-axis. From this diagram, astronomers can study the relationship between temperatu ...
Topics for Today`s Class Luminosity Equation The Heart of
... – Luminosity (or absolute magnitude) versus temperature (or spectral type) ...
... – Luminosity (or absolute magnitude) versus temperature (or spectral type) ...
Chapter 13
... Mass Loss From Stars Stars like our sun are constantly losing mass in a stellar wind ( solar wind). The more massive the star, the stronger its stellar wind. ...
... Mass Loss From Stars Stars like our sun are constantly losing mass in a stellar wind ( solar wind). The more massive the star, the stronger its stellar wind. ...
The Hot-plate Model of a Star Model of Stars— 3 Oct
... hot-plate get to my hand? What are two ways to make a hot plate produce more energy per second? (The same question applies to a star: What are two ways to make a star brighter or more luminous?) What can I do to make the same hot-plate at the same setting burn my hand and not burn my hand? ...
... hot-plate get to my hand? What are two ways to make a hot plate produce more energy per second? (The same question applies to a star: What are two ways to make a star brighter or more luminous?) What can I do to make the same hot-plate at the same setting burn my hand and not burn my hand? ...
Stars
... small points of light because they are very far away. They do not move. The Earth rotates, so we are the ones moving. ...
... small points of light because they are very far away. They do not move. The Earth rotates, so we are the ones moving. ...
lecture23
... All stars in a cluster are of about the same age. Clusters therefore are natural laboratory in which mass, rather than age, of stars is only significant variable. ...
... All stars in a cluster are of about the same age. Clusters therefore are natural laboratory in which mass, rather than age, of stars is only significant variable. ...
NASC 1100
... Spectral Type The surface temperature also determines the line spectrum of a star. Hot stars display lines of highly ionized elements, while cool stars show molecular lines. Stars are classified by assigning a spectral type. The hottest stars are called spectral type O, followed by B, A, F, G, K, M ...
... Spectral Type The surface temperature also determines the line spectrum of a star. Hot stars display lines of highly ionized elements, while cool stars show molecular lines. Stars are classified by assigning a spectral type. The hottest stars are called spectral type O, followed by B, A, F, G, K, M ...
Astronomy Galaxies & The Universe
... The original mass of the star determines its temperature and the color. (Big – glows blue, medium – glows yellow-orange, small – glows red) Red Giants / Red Super-giants form as H2 fuel is used up and gravity overpowers released energy, center core contracts while outer layer expands (He2 + He2 → C ...
... The original mass of the star determines its temperature and the color. (Big – glows blue, medium – glows yellow-orange, small – glows red) Red Giants / Red Super-giants form as H2 fuel is used up and gravity overpowers released energy, center core contracts while outer layer expands (He2 + He2 → C ...
presentation source
... • Shine through fluorescing hydrogen gas. – Red Nebulae (HII regions) (10,000K). ...
... • Shine through fluorescing hydrogen gas. – Red Nebulae (HII regions) (10,000K). ...
Lecture 31: The Properties of Stars
... The color of a star depends on its temperature: cooler stars are redder, hotter stars are blue. Luminosity, the total energy output expressed in Watts or Solar Luminosities, depends on the radius and temperature. The absorption spectra of stars form a distinct sequence with stellar temperature, givi ...
... The color of a star depends on its temperature: cooler stars are redder, hotter stars are blue. Luminosity, the total energy output expressed in Watts or Solar Luminosities, depends on the radius and temperature. The absorption spectra of stars form a distinct sequence with stellar temperature, givi ...
Characteristics of stars
... • Many stars are about the size of the sun, which is a medium sized star. • White dwarfs are about the size of Earth. • Neutron stars are about 20KM (smallest) • Giant stars and super giant stars. If our sun were a super giant star it would fill our solar system as far out as Jupiter. ...
... • Many stars are about the size of the sun, which is a medium sized star. • White dwarfs are about the size of Earth. • Neutron stars are about 20KM (smallest) • Giant stars and super giant stars. If our sun were a super giant star it would fill our solar system as far out as Jupiter. ...
Measuring the Stars
... the main sequence, as this is where most stars are. Also indicated is the white dwarf region; these stars are hot but not very luminous, as they are quite small. ...
... the main sequence, as this is where most stars are. Also indicated is the white dwarf region; these stars are hot but not very luminous, as they are quite small. ...
The Life Cycle of Stars
... It is red because it is cooler than it was in the main sequence star stage and it is a giant because the outer shell has expanded outward. ...
... It is red because it is cooler than it was in the main sequence star stage and it is a giant because the outer shell has expanded outward. ...
Spectroscopy Lecture 10
... Cores of lines with welldeveloped wings show strong departures from LTE ...
... Cores of lines with welldeveloped wings show strong departures from LTE ...
The Lives of Stars
... than large-mass stars, so they have much longer lives • stars that have less mass than the sun use their fuel slowly, and can live for up to 200 billion years • medium-mass stars like the sun live for about 10 billion years • astronomers think the sun is about 4.6 billion years old, so it is almost ...
... than large-mass stars, so they have much longer lives • stars that have less mass than the sun use their fuel slowly, and can live for up to 200 billion years • medium-mass stars like the sun live for about 10 billion years • astronomers think the sun is about 4.6 billion years old, so it is almost ...
Quiz Chapter 10 Answers
... The shockwave from a nearby supernova b) The shockwave from a newly formed high-mass star that is nearby c) The shockwave experienced by the cloud as it passes through a spiral arm d) All of the above X 10-11. Why does the core of a star contract during its time on the main sequence? a) The temperat ...
... The shockwave from a nearby supernova b) The shockwave from a newly formed high-mass star that is nearby c) The shockwave experienced by the cloud as it passes through a spiral arm d) All of the above X 10-11. Why does the core of a star contract during its time on the main sequence? a) The temperat ...
Light from stars part II
... Apparent Magnitude mv (How bright stars appear) • Refined in the 19th Century when instruments became precise enough to accurately measure brightness • Modern scale is defined so that 6th magnitude stars are exactly 100 times brighter than 1st magnitude stars • This means stars that differ in magni ...
... Apparent Magnitude mv (How bright stars appear) • Refined in the 19th Century when instruments became precise enough to accurately measure brightness • Modern scale is defined so that 6th magnitude stars are exactly 100 times brighter than 1st magnitude stars • This means stars that differ in magni ...
Stellar classification
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Light from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with absorption lines. Each line indicates an ion of a certain chemical element, with the line strength indicating the abundance of that ion. The relative abundance of the different ions varies with the temperature of the photosphere. The spectral class of a star is a short code summarizing the ionization state, giving an objective measure of the photosphere's temperature and density.Most stars are currently classified under the Morgan–Keenan (MK) system using the letters O, B, A, F, G, K, and M, a sequence from the hottest (O type) to the coolest (M type). Each letter class is then subdivided using a numeric digit with 0 being hottest and 9 being coolest (e.g. A8, A9, F0, F1 form a sequence from hotter to cooler). The sequence has been expanded with classes for other stars and star-like objects that do not fit in the classical system, such class D for white dwarfs and class C for carbon stars.In the MK system a luminosity class is added to the spectral class using Roman numerals. This is based on the width of certain absorption lines in the star's spectrum which vary with the density of the atmosphere and so distinguish giant stars from dwarfs. Luminosity class 0 or Ia+ stars for hypergiants, class I stars for supergiants, class II for bright giants, class III for regular giants, class IV for sub-giants, class V for main-sequence stars, class sd for sub-dwarfs, and class D for white dwarfs. The full spectral class for the Sun is then G2V, indicating a main-sequence star with a temperature around 5,800K.