Binary Stars
... Stars start out raging hot (blue, bright) and cool off (get redder and fainter) as they use up their fuel, like a dying coal. Stars start out cool, and get hotter and brighter as they use up fuel and contract under the influence of gravity. ...
... Stars start out raging hot (blue, bright) and cool off (get redder and fainter) as they use up their fuel, like a dying coal. Stars start out cool, and get hotter and brighter as they use up fuel and contract under the influence of gravity. ...
Answers to Coursebook questions – Chapter E2
... groupings of stars. Main sequence stars occupy a strip going diagonally down from top left to bottom right, red giants are in the top left part of the diagram and white dwarfs are at the bottom left. ...
... groupings of stars. Main sequence stars occupy a strip going diagonally down from top left to bottom right, red giants are in the top left part of the diagram and white dwarfs are at the bottom left. ...
Scattering (and the blue sky)
... Kirchoff’s Laws 1) An opaque object emits a continuous (blackbody) spectrum. 2) An thin gas cloud produces an emission line spectrum. 3) A thin gas cloud in front of a blackbody source usually produces ...
... Kirchoff’s Laws 1) An opaque object emits a continuous (blackbody) spectrum. 2) An thin gas cloud produces an emission line spectrum. 3) A thin gas cloud in front of a blackbody source usually produces ...
Stars: from Adolescence to Old Age
... inside a star, the faster it uses up its hydrogen fuel Although massive stars have more fuel, they burn it so quickly that their lifetimes are much shorter than those of low-mass stars This also explains why the most massive main-sequence stars are the most luminous 4 August 2005 ...
... inside a star, the faster it uses up its hydrogen fuel Although massive stars have more fuel, they burn it so quickly that their lifetimes are much shorter than those of low-mass stars This also explains why the most massive main-sequence stars are the most luminous 4 August 2005 ...
Today`s Powerpoint
... Blocks out short wavelength light better than long wavelength light => makes objects appear redder. ...
... Blocks out short wavelength light better than long wavelength light => makes objects appear redder. ...
HNRS 227 Lecture #2 Chapters 2 and 3
... apparent brightness The absolute magnitude of a star is the apparent magnitude it would have if viewed from a distance of 10 parsecs ...
... apparent brightness The absolute magnitude of a star is the apparent magnitude it would have if viewed from a distance of 10 parsecs ...
Stars Chapter 21
... light from a distant star into its characteristic color • SPECTRUM: the band of colors that forms as light passes through a prism • Used to see if galaxies are moving away or toward the earth ...
... light from a distant star into its characteristic color • SPECTRUM: the band of colors that forms as light passes through a prism • Used to see if galaxies are moving away or toward the earth ...
hotstar_xrays
... scorpion -- as seen at 10 PM on a June evening from Swarthmore. t Sco is a B0 V star -- with a surface temperature of about 30,000 K (5 times the sun’s temperature), and with about 50,000 times the sun’s luminosity. It has unusual ultraviolet absorption lines, a very low projected rotational velocit ...
... scorpion -- as seen at 10 PM on a June evening from Swarthmore. t Sco is a B0 V star -- with a surface temperature of about 30,000 K (5 times the sun’s temperature), and with about 50,000 times the sun’s luminosity. It has unusual ultraviolet absorption lines, a very low projected rotational velocit ...
ph507lecnote06
... deuterium into helium for a short time, but cannot sustain nuclear reactions. Such “failed” stars are called brown dwarfs. They are similar in size to Jupiter with masses of 10-80 times that of Jupiter • At a temperature of 2 million K, a lithium ato ...
... deuterium into helium for a short time, but cannot sustain nuclear reactions. Such “failed” stars are called brown dwarfs. They are similar in size to Jupiter with masses of 10-80 times that of Jupiter • At a temperature of 2 million K, a lithium ato ...
Binary Orbits
... determine parameters e.g. period and line of sight velocities – masses – done in optical and X-ray • Fact that a large fraction of stars are found in binaries indicate stars are formed in groups through gravitational collapse of ...
... determine parameters e.g. period and line of sight velocities – masses – done in optical and X-ray • Fact that a large fraction of stars are found in binaries indicate stars are formed in groups through gravitational collapse of ...
THE HR DIAGRAM
... Figure 3 illustrates the full scale of an HR diagram. The x‐axis at the top utilizes both spectral class and temperature while at the bottom, the x‐axis uses the B‐V color index. The y‐axis on the left uses luminosity in solar units while absolute magnitudes are at right. This is a plot of 22,00 ...
... Figure 3 illustrates the full scale of an HR diagram. The x‐axis at the top utilizes both spectral class and temperature while at the bottom, the x‐axis uses the B‐V color index. The y‐axis on the left uses luminosity in solar units while absolute magnitudes are at right. This is a plot of 22,00 ...
What is a Hertzsprung
... Low-Dispersion Grating Stellar Spectra, Kitt Peak National Observatory, ...
... Low-Dispersion Grating Stellar Spectra, Kitt Peak National Observatory, ...
HEIC0410: FOR RELEASE 15:00 (CEST)/9:00 AM EDT 15 June
... Both components of the binary system belong to the L spectral class that includes the lowest mass stars and the highest mass brown dwarfs in our solar neighbourhood. This spectral class was discovered in 1997 and was added to the spectral classification that had remained unchanged for half a century ...
... Both components of the binary system belong to the L spectral class that includes the lowest mass stars and the highest mass brown dwarfs in our solar neighbourhood. This spectral class was discovered in 1997 and was added to the spectral classification that had remained unchanged for half a century ...
Lecture
... lifetime by determining its mass (tlife ~ 1/M2.5) • Cold (red ones) stars have longer lifetime than hot stars: – O star: ~ 1 million years – G star (Sun): ~ 10 billion years – M star : ~ 5,000 billion years ...
... lifetime by determining its mass (tlife ~ 1/M2.5) • Cold (red ones) stars have longer lifetime than hot stars: – O star: ~ 1 million years – G star (Sun): ~ 10 billion years – M star : ~ 5,000 billion years ...
Lecture 15: The Main Sequence
... If any of these conditions is not met, the star is not on the main-sequence. These conditions define a region on the H-R diagram where stars hang out for long periods of time. That’s why so many stars in the sky (85%) are on the main sequence. ...
... If any of these conditions is not met, the star is not on the main-sequence. These conditions define a region on the H-R diagram where stars hang out for long periods of time. That’s why so many stars in the sky (85%) are on the main sequence. ...
doc
... million years? Does this suggest that there were few open clusters forming until recently, with our ...
... million years? Does this suggest that there were few open clusters forming until recently, with our ...
More on Cluster HR diagrams - University of Texas Astronomy
... At this point you should be able to look at Figures 19.17 (open cluster) and 19.18 (globular cluster) on p. 519 of your book, and understand clearly how we know that one was “just born” recently (about 100 million years ago), while the other must be extremely old, about 10 billion years. Can you now ...
... At this point you should be able to look at Figures 19.17 (open cluster) and 19.18 (globular cluster) on p. 519 of your book, and understand clearly how we know that one was “just born” recently (about 100 million years ago), while the other must be extremely old, about 10 billion years. Can you now ...
Galaxy Notes Presentation
... Cannot actually count the number of stars in the galaxy, can estimate as roughly 100 billion ...
... Cannot actually count the number of stars in the galaxy, can estimate as roughly 100 billion ...
The Hertzsprung-Russell Diagram
... 9. Label the following steps on your H-R diagram to show the series of changes that our sun has undergone since its formation 4.6 billion years ago. a. Originally, a big cloud of gas and dust called a nebula condensed to form a young, cool star called a red dwarf. In this first stage of life, our s ...
... 9. Label the following steps on your H-R diagram to show the series of changes that our sun has undergone since its formation 4.6 billion years ago. a. Originally, a big cloud of gas and dust called a nebula condensed to form a young, cool star called a red dwarf. In this first stage of life, our s ...
EMR, Telescopes, Stars, Solar System study guide `14-15
... violet short) and energy (red low to violet high). • Know the three main types of electromagnetic radiation from the sun and their relative wavelengths (longest to shortest) and energies (highest to lowest): infrared (IR), visible, ultraviolet (UV). • Know the difference between a refracting telesco ...
... violet short) and energy (red low to violet high). • Know the three main types of electromagnetic radiation from the sun and their relative wavelengths (longest to shortest) and energies (highest to lowest): infrared (IR), visible, ultraviolet (UV). • Know the difference between a refracting telesco ...
Ch 3 Sec 1 Tools of modern astronomy
... 2. What’s left is smaller and denser than a dwarf. It’s called a neutron star. May be 3X as massive as our sum, but only 20 km across D. The biggest stars, more than 40X the sun, leave behind a black hole 1. There is no hole – it just looks like one 2. The star is so massive that its gravity is extr ...
... 2. What’s left is smaller and denser than a dwarf. It’s called a neutron star. May be 3X as massive as our sum, but only 20 km across D. The biggest stars, more than 40X the sun, leave behind a black hole 1. There is no hole – it just looks like one 2. The star is so massive that its gravity is extr ...
Chapter 26.4
... Star A has a magnitude of 2 Star B has a magnitude of 1 1. Which is brighter? 2. Bernard’s Star is one of the closest stars to us. It has a magnitude of 8. What conclusions can you make about Proxima Centauri based on this? ...
... Star A has a magnitude of 2 Star B has a magnitude of 1 1. Which is brighter? 2. Bernard’s Star is one of the closest stars to us. It has a magnitude of 8. What conclusions can you make about Proxima Centauri based on this? ...
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.