Astrophysics
... • From these figures it was calculated that if the Sun was made of coal, it could burn for about 10,000 years given a lot of oxygen! As life on the Earth seemed to be millions of years old this appeared to be a problem! • Lord Kelvin and Hermann von Helmholtz suggested that the collapsing matter for ...
... • From these figures it was calculated that if the Sun was made of coal, it could burn for about 10,000 years given a lot of oxygen! As life on the Earth seemed to be millions of years old this appeared to be a problem! • Lord Kelvin and Hermann von Helmholtz suggested that the collapsing matter for ...
what are stars made of?
... The hottest stars are blue and white Blue and white stars are the hottest main sequence stars. Smaller bluish-white stars have a surface temperature from about 7500°C to 10 000°C. The surface of larger, brighter blue stars can be as hot as 60 000°C. ...
... The hottest stars are blue and white Blue and white stars are the hottest main sequence stars. Smaller bluish-white stars have a surface temperature from about 7500°C to 10 000°C. The surface of larger, brighter blue stars can be as hot as 60 000°C. ...
Astronomy Assignment #1
... 7. Are all red giants or supergiants very massive stars? Why are red giants so big and red? What is going on inside the giants? All red giant and supergiants evolve from relatively massive stars. Any main sequence star that hotter than midK spectral type can become a giant star. So, not all giant st ...
... 7. Are all red giants or supergiants very massive stars? Why are red giants so big and red? What is going on inside the giants? All red giant and supergiants evolve from relatively massive stars. Any main sequence star that hotter than midK spectral type can become a giant star. So, not all giant st ...
answer key
... Explosive Collisions Stars (After 4th intro frame) 16. What do these super large stars produce? 17. What happens when 2 neutron stars collide? What is produced? 18. What is the chance of a collision between the sun and another star? Failed Stars (After 5th intro frame) 19. What are “blue stragglers” ...
... Explosive Collisions Stars (After 4th intro frame) 16. What do these super large stars produce? 17. What happens when 2 neutron stars collide? What is produced? 18. What is the chance of a collision between the sun and another star? Failed Stars (After 5th intro frame) 19. What are “blue stragglers” ...
1:45 PM TuTh This is a one-quarter course on
... oriented. However, it should also be accessible to highly motivated non-science majors with some background in math and exposure to physical principles (see below). Our studies in Astronomy 12 will require knowledge of simple mechanics and some basic ideas about radiation theory, quantum mechanics, ...
... oriented. However, it should also be accessible to highly motivated non-science majors with some background in math and exposure to physical principles (see below). Our studies in Astronomy 12 will require knowledge of simple mechanics and some basic ideas about radiation theory, quantum mechanics, ...
but restricted to nearby large stars
... • Spectral letter is enhanced by a number from 0 to 9 indicating tenths of the range between two star classes. • E.g., A5 is five tenths between A0 and F0, but A2 is two tenths of the full range from A0 to F0. ...
... • Spectral letter is enhanced by a number from 0 to 9 indicating tenths of the range between two star classes. • E.g., A5 is five tenths between A0 and F0, but A2 is two tenths of the full range from A0 to F0. ...
Lecture 14
... Collapse only continues if the cloud cools by radiating away heat. If the initial cloud was spinning a protostellar disk is formed. Protostars approach the main sequence from the right hand side of the HR diagram. Jets can be formed as the protostar collapses. When core gets hot enough, fusion H to ...
... Collapse only continues if the cloud cools by radiating away heat. If the initial cloud was spinning a protostellar disk is formed. Protostars approach the main sequence from the right hand side of the HR diagram. Jets can be formed as the protostar collapses. When core gets hot enough, fusion H to ...
Scientists discover surprising importance of `I Love Q` for
... published their work in "Science," the world's leading journal of scientific research, global news The reason – discovered by Yunes and postdoctoral scholar Kent Yagi—is almost universal and commentary. The weekly publication is read by relations among three intrinsic properties of these an estimate ...
... published their work in "Science," the world's leading journal of scientific research, global news The reason – discovered by Yunes and postdoctoral scholar Kent Yagi—is almost universal and commentary. The weekly publication is read by relations among three intrinsic properties of these an estimate ...
Stars and Galaxies
... • Mass of massive stars 6x that of sun • Take same path as medium-sized stars except for after red giant stage they do not become white dwarfs • Carbon atoms continue to fuse creating heavier elements like oxygen & nitrogen • Core of massive star so hot that fusion continues until the heavy element ...
... • Mass of massive stars 6x that of sun • Take same path as medium-sized stars except for after red giant stage they do not become white dwarfs • Carbon atoms continue to fuse creating heavier elements like oxygen & nitrogen • Core of massive star so hot that fusion continues until the heavy element ...
Lecture (Powerpoint)
... the mass of the Sun, or ~80 Jupiter masses) never ``turn on'' Central temperatures never get hot enough for nuclear burning to begin in earnest Nuclear burning is what powers the star through its life Star sits around as a brown dwarf – too big and hot to be a planet, too small and cold to be a real ...
... the mass of the Sun, or ~80 Jupiter masses) never ``turn on'' Central temperatures never get hot enough for nuclear burning to begin in earnest Nuclear burning is what powers the star through its life Star sits around as a brown dwarf – too big and hot to be a planet, too small and cold to be a real ...
Stellar Characteristics and Evolution
... When the core temperature becomes high enough through the He-burning, the core expands and cools and becomes non-degenerate again. The star then settles down on a “Horizontal Branch” (or “Helium Burning Main Sequence”) and contracts and dims, burning Helium in its core and Hydrogen in shell around c ...
... When the core temperature becomes high enough through the He-burning, the core expands and cools and becomes non-degenerate again. The star then settles down on a “Horizontal Branch” (or “Helium Burning Main Sequence”) and contracts and dims, burning Helium in its core and Hydrogen in shell around c ...
Lecture 10: The Milky Way
... We live in a galaxy that has three major components of different ages and metallicities. Disc (thin+thick) – about 25kpc in radius, only about 1kpc thick. Most of the stars are young (0-8 Gyr), and have about the same metal content as the Sun. Total stellar mass of about 6x1010M. Bulge – a mostly o ...
... We live in a galaxy that has three major components of different ages and metallicities. Disc (thin+thick) – about 25kpc in radius, only about 1kpc thick. Most of the stars are young (0-8 Gyr), and have about the same metal content as the Sun. Total stellar mass of about 6x1010M. Bulge – a mostly o ...
High-Speed Ballistic Stellar Interlopers
... the ages, masses, and velocities of these interlopers. The stars appear to be young—just millions of years old. Their ages are based partly on their strong stellar winds. Most stars produce powerful winds either when they are very young or very old. Only stars greater than 10 times the Sun’s mass ha ...
... the ages, masses, and velocities of these interlopers. The stars appear to be young—just millions of years old. Their ages are based partly on their strong stellar winds. Most stars produce powerful winds either when they are very young or very old. Only stars greater than 10 times the Sun’s mass ha ...
Diffuse Ultraviolet Emission in Galaxies
... went back to the ACS exposures to investigate the locations of the O and B stars with respect to the bright knots of gas and dust where stars are forming. When a giant cloud contracts under the force of gravity or external compression, it becomes a nursery of newborn stars, which form in collapsing ...
... went back to the ACS exposures to investigate the locations of the O and B stars with respect to the bright knots of gas and dust where stars are forming. When a giant cloud contracts under the force of gravity or external compression, it becomes a nursery of newborn stars, which form in collapsing ...
The Origin of the Elements - Indiana University Astronomy
... massive stars explode When stars finally deplete their nuclear fuel, they become white dwarfs, neutron stars, or black holes. In the process, much of the stellar material is returned to ...
... massive stars explode When stars finally deplete their nuclear fuel, they become white dwarfs, neutron stars, or black holes. In the process, much of the stellar material is returned to ...
What is a star?
... How is star brightness measured? • Astronomers used telescopes see many stars that are too dim to see with the unaided eye. They added to the magnitude system. • Today, the brightest stars have a magnitude of about –2, and the faintest stars that we can see with a telescope have a magnitude of +30. ...
... How is star brightness measured? • Astronomers used telescopes see many stars that are too dim to see with the unaided eye. They added to the magnitude system. • Today, the brightest stars have a magnitude of about –2, and the faintest stars that we can see with a telescope have a magnitude of +30. ...
Chapter 8 – Continuous Absorption
... • Independent of wavelength • In hot stars (O and early B) where hydrogen dominates, then Pe~0.5Pg, and (e) is independent of pressure • In cool stars, e- scattering is small compared to other absorbers for main sequence star but is more important for higher luminosity stars ...
... • Independent of wavelength • In hot stars (O and early B) where hydrogen dominates, then Pe~0.5Pg, and (e) is independent of pressure • In cool stars, e- scattering is small compared to other absorbers for main sequence star but is more important for higher luminosity stars ...
Packet 3
... Problem: What types of visible spectra are emitted from glowing objects? Background information: Astronomers have learned about our universe through the study of light given off by stars. Therefore it is important to understand light. In 1665 Newton observed that when white light passes through a pr ...
... Problem: What types of visible spectra are emitted from glowing objects? Background information: Astronomers have learned about our universe through the study of light given off by stars. Therefore it is important to understand light. In 1665 Newton observed that when white light passes through a pr ...
The woman who dissected the Sun
... quantum theory and the realisation, by the Danish physicist Niels Bohr in 1913, that an atom's electrons circle a nucleus in "discrete" orbits and emit or absorb light when they jump from one orbit to another. Crucially, an electron can absorb enough energy to be kicked out of an atom altogether. Th ...
... quantum theory and the realisation, by the Danish physicist Niels Bohr in 1913, that an atom's electrons circle a nucleus in "discrete" orbits and emit or absorb light when they jump from one orbit to another. Crucially, an electron can absorb enough energy to be kicked out of an atom altogether. Th ...
The First Stars - Amazon Web Services
... stars. These tracers are the ratios of certain elements to a standard tracer such as iron. Iron is a useful age indicator since it is the ultimate endpoint of thermonuclear combustion and ejected in supernovae throughout the history of the universe. If we find an iron-poor environment, we can be sur ...
... stars. These tracers are the ratios of certain elements to a standard tracer such as iron. Iron is a useful age indicator since it is the ultimate endpoint of thermonuclear combustion and ejected in supernovae throughout the history of the universe. If we find an iron-poor environment, we can be sur ...
Return both exam and scantron sheet when you
... 38. The surface temperature of the Sun is determined from (a) its distance and luminosity. (b) its distance and brightness. (c) its spectrum using the Stefan-Boltzmann law. (d) its spectrum using the Wien’s law. 39. The luminosity of the Sun is determined from (a) its distance and luminosity. (b) it ...
... 38. The surface temperature of the Sun is determined from (a) its distance and luminosity. (b) its distance and brightness. (c) its spectrum using the Stefan-Boltzmann law. (d) its spectrum using the Wien’s law. 39. The luminosity of the Sun is determined from (a) its distance and luminosity. (b) it ...
2.1 Introduction
... associated with the Carina nebula at a distance of 3.2 kpc. It is immediately obvious from these images that: (a) stars have a range of colours, and (b) some stars are intrinsically brighter than others. More generally, we can make a list of what we may consider to be the most important physical pro ...
... associated with the Carina nebula at a distance of 3.2 kpc. It is immediately obvious from these images that: (a) stars have a range of colours, and (b) some stars are intrinsically brighter than others. More generally, we can make a list of what we may consider to be the most important physical pro ...
The Sun and other Stars
... of mass to generate a large quantity of energy. This lead the way for two astrophysicists to determine that the Sun was powered by the fusion of Hydrogen ...
... of mass to generate a large quantity of energy. This lead the way for two astrophysicists to determine that the Sun was powered by the fusion of Hydrogen ...
Spectral Analysis Lab
... If you have ever looked closely at stars, you may have noticed that they are not all the same color. Scientists have found that they can learn a great deal about a star’s temperature and composition by analyzing the light it emits. How is this possible? When white light passes through a prism, it ap ...
... If you have ever looked closely at stars, you may have noticed that they are not all the same color. Scientists have found that they can learn a great deal about a star’s temperature and composition by analyzing the light it emits. How is this possible? When white light passes through a prism, it ap ...
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.