SPA 302: THE EVOLUTION OF STARS LECTURE 1: BASICS OF
... 1.3.2 Brightness and Luminosity of Stars The luminosity of a star, denoted by L, is one of the most important characteristics of stars. It is measured in Watts (W) or as a multiple of the Sun's luminosity Lʘ and it is the amount of energy emitted per unit are of a star surface per second. However, i ...
... 1.3.2 Brightness and Luminosity of Stars The luminosity of a star, denoted by L, is one of the most important characteristics of stars. It is measured in Watts (W) or as a multiple of the Sun's luminosity Lʘ and it is the amount of energy emitted per unit are of a star surface per second. However, i ...
![31 — Main-Sequence Stars [Revision : 1.1]](http://s1.studyres.com/store/data/015926256_1-97d746cbe97ccc13b433136b208bf071-300x300.png)
31 — Main-Sequence Stars [Revision : 1.1]
... ∗ To transport all energy by radiation, temperature gradient very steep; convection sets in ∗ So, convective core ∗ Convection is very efficient, so ∇ = ∇ad to high degree of accuracy ∗ Convection mixes composition changes due to nuclear burning; so, flat composition profile in core – In envelopes o ...
... ∗ To transport all energy by radiation, temperature gradient very steep; convection sets in ∗ So, convective core ∗ Convection is very efficient, so ∇ = ∇ad to high degree of accuracy ∗ Convection mixes composition changes due to nuclear burning; so, flat composition profile in core – In envelopes o ...
Lecture 5: Light as a tool
... Apparent magnitude tells us nothing about the luminosity of the objects, but it tell us how difficult it is to see the objects in the sky. Absolute magnitude, on the other hand, is directly related to the luminosity of the object. But it does not tell us how bright they appear in the sky. ...
... Apparent magnitude tells us nothing about the luminosity of the objects, but it tell us how difficult it is to see the objects in the sky. Absolute magnitude, on the other hand, is directly related to the luminosity of the object. But it does not tell us how bright they appear in the sky. ...
Measuring Stars
... But due to absorption lines and bands in the spectrum it could get complicated. Spectral lines in the spectrum provide a additional information about the temperature of a star. Absorption line strength in a stellar spectrum is mostly controlled by the star temperature – Above 25000K show absorption ...
... But due to absorption lines and bands in the spectrum it could get complicated. Spectral lines in the spectrum provide a additional information about the temperature of a star. Absorption line strength in a stellar spectrum is mostly controlled by the star temperature – Above 25000K show absorption ...
Stellar evolution
... - First occurs in a runaway process: "the helium flash". Energy from fusion goes into re-expanding and cooling the core. This slows fusion, so star gets dimmer again. - Then stable He -> C burning. Still have H -> He shell burning surrounding it. ...
... - First occurs in a runaway process: "the helium flash". Energy from fusion goes into re-expanding and cooling the core. This slows fusion, so star gets dimmer again. - Then stable He -> C burning. Still have H -> He shell burning surrounding it. ...
Characteristics of Stars
... All stars are huge spheres of glowing gas They are made mostly of hydrogen They produce energy through nuclear fusion They are classified according to their physical characteristics • Characteristics used to classify stars include: color, temperature, size, composition, and brightness ...
... All stars are huge spheres of glowing gas They are made mostly of hydrogen They produce energy through nuclear fusion They are classified according to their physical characteristics • Characteristics used to classify stars include: color, temperature, size, composition, and brightness ...
Stars Notes
... 4.b – Students know that the Sun is one of many stars in the Milky Way galaxy and that stars may differ in size, temperature and color 4.d – Students know that stars are the source of light for all bright objects in outer space and that the Moon and planets shine by reflected sunlight, not by thei ...
... 4.b – Students know that the Sun is one of many stars in the Milky Way galaxy and that stars may differ in size, temperature and color 4.d – Students know that stars are the source of light for all bright objects in outer space and that the Moon and planets shine by reflected sunlight, not by thei ...
Astronomy Library wk 6.cwk (WP)
... Examples would include the filaments of light bulbs and “red hot” metals. ...
... Examples would include the filaments of light bulbs and “red hot” metals. ...
The most important questions to study for the exam
... • It consists almost entirely of hot, bright stars. 8. A certain star is seen to have a relatively low surface temperature but a very high luminosity. What can we conclude from these observations? • The star is a main-sequence star, about the size of the Sun. • The star must be very large. • The sta ...
... • It consists almost entirely of hot, bright stars. 8. A certain star is seen to have a relatively low surface temperature but a very high luminosity. What can we conclude from these observations? • The star is a main-sequence star, about the size of the Sun. • The star must be very large. • The sta ...
MSci Astrophysics 210PHY412 - Queen's University Belfast
... star if it were placed at a distance of 10 pc m – M = 5 log(d/10) - 5 where d is in pc (note: log10 ) • Magnitudes are measured in some wavelength band e.g. UBV. To compare with theory it is more useful to determine bolometric magnitude – defined as absolute magnitude that would be measured by a bol ...
... star if it were placed at a distance of 10 pc m – M = 5 log(d/10) - 5 where d is in pc (note: log10 ) • Magnitudes are measured in some wavelength band e.g. UBV. To compare with theory it is more useful to determine bolometric magnitude – defined as absolute magnitude that would be measured by a bol ...
class17
... Thought Question How would the apparent brightness of Alpha Centauri change if it were three times farther away? ...
... Thought Question How would the apparent brightness of Alpha Centauri change if it were three times farther away? ...
34ReviewNuclear
... B. Studying absorption lines in stars C. Studying binary star orbits D. Studying the brightnesses of stars E. Only by estimation Hotter stars will be bluer, cooler stars will be redder. However, there’s a possibility you might get confused by intervening dust between us and the star, which might mak ...
... B. Studying absorption lines in stars C. Studying binary star orbits D. Studying the brightnesses of stars E. Only by estimation Hotter stars will be bluer, cooler stars will be redder. However, there’s a possibility you might get confused by intervening dust between us and the star, which might mak ...
Chapter 17 Measuring the Stars
... measured. Once this is done, Kepler’s third law gives the sum of the masses of the two stars. Then the relative speeds of the two stars can be measured using the Doppler effect; the speed will be inversely proportional to the mass. This allows us to calculate the mass of each star. ...
... measured. Once this is done, Kepler’s third law gives the sum of the masses of the two stars. Then the relative speeds of the two stars can be measured using the Doppler effect; the speed will be inversely proportional to the mass. This allows us to calculate the mass of each star. ...
Life of stars, formation of elements
... • Built up of molecules of most common elements after hydrogen and helium • Core: Silicates or Graphite (Si, O, C) • Mantle: C,N,O combined with H ...
... • Built up of molecules of most common elements after hydrogen and helium • Core: Silicates or Graphite (Si, O, C) • Mantle: C,N,O combined with H ...
h-r_diagram_online_lab
... Step 2: Convert the Spectral class types into numbers, such that O is 0, B is 1, A is 2, et cetera. Highlight the data in the column labeled “Type.” Go to the “Edit” menu and choose “Replace.” In the pop-up search window, type “O” in the “Replace” line and “0.” in the “Replace with” line. (Don’t for ...
... Step 2: Convert the Spectral class types into numbers, such that O is 0, B is 1, A is 2, et cetera. Highlight the data in the column labeled “Type.” Go to the “Edit” menu and choose “Replace.” In the pop-up search window, type “O” in the “Replace” line and “0.” in the “Replace with” line. (Don’t for ...
Star Spectra - Renton School District
... 4. Try out the other available spectra. Do any others have lines that match? ___________ 5. Which elements have contributed to the spectrum of star 1? _________________________ Note: The elements in a star’s spectrum do not necessarily reflect what the star is made of. The absorption spectrum is mos ...
... 4. Try out the other available spectra. Do any others have lines that match? ___________ 5. Which elements have contributed to the spectrum of star 1? _________________________ Note: The elements in a star’s spectrum do not necessarily reflect what the star is made of. The absorption spectrum is mos ...
Monday, April 15
... The Key Tool to understanding Stars: the Hertzsprung-Russell diagram • Hertzsprung-Russell diagram is luminosity vs. spectral type (or temperature) • To obtain a HR diagram: – get the luminosity. This is your y-coordinate. – Then take the spectral type as your x-coordinate, e.g. K5 for Aldebaran. F ...
... The Key Tool to understanding Stars: the Hertzsprung-Russell diagram • Hertzsprung-Russell diagram is luminosity vs. spectral type (or temperature) • To obtain a HR diagram: – get the luminosity. This is your y-coordinate. – Then take the spectral type as your x-coordinate, e.g. K5 for Aldebaran. F ...
Directed Reading A
... _____ 18. left side of modern H-R diagram 19. Place these stars in order from earliest in life cycle to oldest in life cycle: red giant, white dwarf, main-sequence star. _______________________________________________________________ _______________________________________________________________ __ ...
... _____ 18. left side of modern H-R diagram 19. Place these stars in order from earliest in life cycle to oldest in life cycle: red giant, white dwarf, main-sequence star. _______________________________________________________________ _______________________________________________________________ __ ...
Astronomy 103
... She consolidated an earlier classification by William Pickering that had been arranged alphabetically according to the strength of their hydrogen absorption lines. A – strongest H lines, B – weaker . . . Down to “P” ...
... She consolidated an earlier classification by William Pickering that had been arranged alphabetically according to the strength of their hydrogen absorption lines. A – strongest H lines, B – weaker . . . Down to “P” ...
ILÍDIO LOPES ()
... The κ-mechanism acts like an heat engine, converting thermal into mechanical energy. The stochastic driving is the main mechanism acting in sun-like stars and thus particularly important for our work. Here, the modes are driven stochastically by the turbulence of the subsurface convective zone. ...
... The κ-mechanism acts like an heat engine, converting thermal into mechanical energy. The stochastic driving is the main mechanism acting in sun-like stars and thus particularly important for our work. Here, the modes are driven stochastically by the turbulence of the subsurface convective zone. ...
Nebulas & Stars
... • Nebulas are made up of gas left behind by stars forming or exploding • stars are hot balls of hydrogen and helium, with nuclear fusion at their core • A pulsar is a neutron star that emits beams of radiation that sweep through Earth's line of sight • Quasars are extremely bright masses of energy ...
... • Nebulas are made up of gas left behind by stars forming or exploding • stars are hot balls of hydrogen and helium, with nuclear fusion at their core • A pulsar is a neutron star that emits beams of radiation that sweep through Earth's line of sight • Quasars are extremely bright masses of energy ...
Lecture 12
... L = 4pR 2 ¥ sTe4 …which relates L, R and Te - so only three independent quantities to measure - mass plus two of luminosity, radius, and effective temperature. ...
... L = 4pR 2 ¥ sTe4 …which relates L, R and Te - so only three independent quantities to measure - mass plus two of luminosity, radius, and effective temperature. ...
Constellation Information
... This is a winter landmark everyone ought to know. Orion is the boldest and brightest of all the constellations. The three belt stars and two other (Bellatrix and Saiph) shine about as bright as the stars of the Big Dipper. But added to these are two that are even brighter: blue-white Rigel, marking ...
... This is a winter landmark everyone ought to know. Orion is the boldest and brightest of all the constellations. The three belt stars and two other (Bellatrix and Saiph) shine about as bright as the stars of the Big Dipper. But added to these are two that are even brighter: blue-white Rigel, marking ...
DR 19.2 - Cobb Learning
... massive blue stars white dwarf stars main-sequence stars red dwarf stars red giant stars ...
... massive blue stars white dwarf stars main-sequence stars red dwarf stars red giant stars ...
What is a star? A star is a giant ball of gases held together by gravity
... If you have ever looked at a fire, you know that parts of it are different colors. Different colors are made by different degrees of temperature. Stars burning at different temperatures also look different colors. The coolest stars are red. They are also called M-type stars. Our sun is a G-type star ...
... If you have ever looked at a fire, you know that parts of it are different colors. Different colors are made by different degrees of temperature. Stars burning at different temperatures also look different colors. The coolest stars are red. They are also called M-type stars. Our sun is a G-type star ...
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.