ESA-ESO Working Group on the Galaxy
... •Low surface brightness -> need to go as far down on RGB •Need to follow stream across large area on the sky -> Wide-field, accurate RV, faint magnitudes, multiplex ~ 100 ...
... •Low surface brightness -> need to go as far down on RGB •Need to follow stream across large area on the sky -> Wide-field, accurate RV, faint magnitudes, multiplex ~ 100 ...
Properties of Stars
... Some binaries are too close together to be resolved, you may still be able to detect the binary through the Doppler shift (in one or both stars). They must be relatively close to each other (short orbital period). If you can see both stars’ spectrums, you may be able to use Doppler shifts to measure ...
... Some binaries are too close together to be resolved, you may still be able to detect the binary through the Doppler shift (in one or both stars). They must be relatively close to each other (short orbital period). If you can see both stars’ spectrums, you may be able to use Doppler shifts to measure ...
The Family of Stars
... more luminous than star A, so star B must be further away. The flux received from both stars is the same, but star B is 100 times more luminous than star A, so star B must be further away. Both stars are equally luminous, but the flux received from star A is 5 times less than from star B, so star A ...
... more luminous than star A, so star B must be further away. The flux received from both stars is the same, but star B is 100 times more luminous than star A, so star B must be further away. Both stars are equally luminous, but the flux received from star A is 5 times less than from star B, so star A ...
Sample Stellar Evolution TEST QUESTIONS
... 10. Hydrostatic equilibrium refers to the balance between weight and pressure. 11. The Orion region contains young main sequence stars and an emission nebula. 12. The thermal motions of the atoms in a gas cloud can make it collapse to form a protostar. 13. The pressure of a gas generally depends on ...
... 10. Hydrostatic equilibrium refers to the balance between weight and pressure. 11. The Orion region contains young main sequence stars and an emission nebula. 12. The thermal motions of the atoms in a gas cloud can make it collapse to form a protostar. 13. The pressure of a gas generally depends on ...
Problem Set No. 5
... 2. Why do some astronomers say that brown dwarfs are not really stars? Why are brown dwarfs hard to study? Some astronomers would say that true stars must have nuclear fusion as an internal energy source. Brown dwarfs are too cool the burn hydrogen. Even though there are nearby brown dwarfs, their ...
... 2. Why do some astronomers say that brown dwarfs are not really stars? Why are brown dwarfs hard to study? Some astronomers would say that true stars must have nuclear fusion as an internal energy source. Brown dwarfs are too cool the burn hydrogen. Even though there are nearby brown dwarfs, their ...
Nebulas - WLWV Staff Blogs
... together to create larger masses, which then gather other material until they become big enough to be known as stars. ...
... together to create larger masses, which then gather other material until they become big enough to be known as stars. ...
Stars Study Guide KEY
... 12. Why do stars with more mass tend to be brighter than low mass stars? High mass stars have more self-gravity which causes them to burn at a higher temperature and to appear brighter. 13. How do white dwarfs and neutron stars compare in size to our Sun? They are both smaller than our Sun. White d ...
... 12. Why do stars with more mass tend to be brighter than low mass stars? High mass stars have more self-gravity which causes them to burn at a higher temperature and to appear brighter. 13. How do white dwarfs and neutron stars compare in size to our Sun? They are both smaller than our Sun. White d ...
Big Bang and Life Cycle of Stars
... - first Hydrogen and Helium, but it had to cool still more for the other elements to start to form and be neutral ...
... - first Hydrogen and Helium, but it had to cool still more for the other elements to start to form and be neutral ...
A Summary of Stages
... suns) will not have enough "squeeze" in its core to initiate fusion; such objects (termed brown dwarfs) will be dim and cool and, as they grow older, will only grow dimmer and cooler, ultimately becoming black dwarfs (see STAGE 14). Astronomers have identified several brown dwarf candidates, and eve ...
... suns) will not have enough "squeeze" in its core to initiate fusion; such objects (termed brown dwarfs) will be dim and cool and, as they grow older, will only grow dimmer and cooler, ultimately becoming black dwarfs (see STAGE 14). Astronomers have identified several brown dwarf candidates, and eve ...
Universe Now - Course Pages of Physics Department
... • The structure of a black hole: – Singularity: the location of the entire mass – infinite density. – Event horizon: an undetectable surface which marks the point of inevitable falling into singularity. The radius can be calculated if the mass is known (for 1 M, 3 km). ...
... • The structure of a black hole: – Singularity: the location of the entire mass – infinite density. – Event horizon: an undetectable surface which marks the point of inevitable falling into singularity. The radius can be calculated if the mass is known (for 1 M, 3 km). ...
Characteristics of Main Sequence Stars
... nuclear reactions in high mass stars are generally confined to a very small region, much smaller than the size of the convective core. • As the stellar mass increases, so does the size of the convective core (due again to the large increase in ² with temperature). Supermassive stars with M ∼ 100M¯ w ...
... nuclear reactions in high mass stars are generally confined to a very small region, much smaller than the size of the convective core. • As the stellar mass increases, so does the size of the convective core (due again to the large increase in ² with temperature). Supermassive stars with M ∼ 100M¯ w ...
guide to orion 3-d flythrough
... massive stars in a kite-like arrangement. The brightest of these stars, which has a luminosity 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 g ...
... massive stars in a kite-like arrangement. The brightest of these stars, which has a luminosity 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 g ...
Stellar Evolution and the Herzsprung-Russell Diagram
... particles). This fusion requires fuel, plus high temperature and density • Energy is “transported” from the core to the photosphere by a combination of photons (radiative transport) and boiling fluid motion (convective transport) • At all locations in the star, the pressure force from hot gas oppose ...
... particles). This fusion requires fuel, plus high temperature and density • Energy is “transported” from the core to the photosphere by a combination of photons (radiative transport) and boiling fluid motion (convective transport) • At all locations in the star, the pressure force from hot gas oppose ...
Light and Spectra I (Professor Powerpoint)
... has a continuous spectrum. Example : the Sun and a light bulb There is energy at all wavelengths ...
... has a continuous spectrum. Example : the Sun and a light bulb There is energy at all wavelengths ...
Evolution of low
... stars in many of the evolutionary phases. Can test timescale, surface temperature and luminosity predictions. After 30 years of testing, it looks like we understand the basic evolution of stars very well. (2) My personal favorite test is the measurement of radioactive Tc in AGB stars. ...
... stars in many of the evolutionary phases. Can test timescale, surface temperature and luminosity predictions. After 30 years of testing, it looks like we understand the basic evolution of stars very well. (2) My personal favorite test is the measurement of radioactive Tc in AGB stars. ...
day10spectral_analysi+
... All objects emit electromagnetic radiation, called blackbody radiation. As the temperature increases, the wavelength of the peak of the emission shifts to shorter wavelength (which has higher frequency). At several hundred degrees, objects emit some visible light, and the emission spreads across the ...
... All objects emit electromagnetic radiation, called blackbody radiation. As the temperature increases, the wavelength of the peak of the emission shifts to shorter wavelength (which has higher frequency). At several hundred degrees, objects emit some visible light, and the emission spreads across the ...
A Story about a Star`s Life
... How I wonder what you are… • Stars have • Different colors • Which indicate different temperatures ...
... How I wonder what you are… • Stars have • Different colors • Which indicate different temperatures ...
HR-Diagram
... the outer star that the collapse causes a Super Nova Explosion. NOW…if the CORE of the star has a mass of 3x or less the size of the sun ( but has a much smaller diameter than the sun) it creates a Neutron Star which spins and emits a steady beam of radiation and light out of its poles. *Neutron sta ...
... the outer star that the collapse causes a Super Nova Explosion. NOW…if the CORE of the star has a mass of 3x or less the size of the sun ( but has a much smaller diameter than the sun) it creates a Neutron Star which spins and emits a steady beam of radiation and light out of its poles. *Neutron sta ...
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. ...
Star Classification - University of Louisville
... collapse. As the cloud collapses, gravity, temperature, and pressure increase, until the cloud has collapsed enough to raise the temperature to that required to fuse (burn) the hydrogen. • Once that fusion begins, the energy released halts the contraction, and the outer layers of gas are blown away. ...
... collapse. As the cloud collapses, gravity, temperature, and pressure increase, until the cloud has collapsed enough to raise the temperature to that required to fuse (burn) the hydrogen. • Once that fusion begins, the energy released halts the contraction, and the outer layers of gas are blown away. ...
Lecture 11, PPT version
... If both sets of lines shift by the same amount, the stars have the same mass. If one set of lines shifts twice as far as the other set, the big star is twice as massive as the small star. If one set of lines shifts three times as far as the other set, the big star is three times as massive as the sm ...
... If both sets of lines shift by the same amount, the stars have the same mass. If one set of lines shifts twice as far as the other set, the big star is twice as massive as the small star. If one set of lines shifts three times as far as the other set, the big star is three times as massive as the sm ...
File
... A galaxy is a very large group of stars held together by gravity. It may contain as few as a 100,000 stars, or as many as several trillion stars. Our Sun is one star in our Milky Way Galaxy, which may contain about 200 to 400 billion stars and measure about 100,000 light years in diameter. (A light ...
... A galaxy is a very large group of stars held together by gravity. It may contain as few as a 100,000 stars, or as many as several trillion stars. Our Sun is one star in our Milky Way Galaxy, which may contain about 200 to 400 billion stars and measure about 100,000 light years in diameter. (A light ...
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.