AST_s309_ss11_2 - University of Texas at Austin
... Good RV precision → cool stars of spectral type later than F6 Poor RV precision → hot stars of spectral type earlier than F6 ...
... Good RV precision → cool stars of spectral type later than F6 Poor RV precision → hot stars of spectral type earlier than F6 ...
3. Measuring Distances and Magnitudes
... always appear less bright below the Earth's atmosphere than above it. 1 clear unit airmass transmits 82% in the visual, i.e. it dims by 0.215mag. Air Mass is the path length that light from a celestial object takes through Earth’s atmosphere relative to the length at the zenith. The airmass is 1 at ...
... always appear less bright below the Earth's atmosphere than above it. 1 clear unit airmass transmits 82% in the visual, i.e. it dims by 0.215mag. Air Mass is the path length that light from a celestial object takes through Earth’s atmosphere relative to the length at the zenith. The airmass is 1 at ...
Gamma Ray Bursts
... collisions of two very dense objects, such as neutron stars in a binary. Also, some think, they could be from the same process as the long GRB but were not directly along the axis of the emission, i.e. not seeing it face on. ...
... collisions of two very dense objects, such as neutron stars in a binary. Also, some think, they could be from the same process as the long GRB but were not directly along the axis of the emission, i.e. not seeing it face on. ...
ppt
... Comparisons between observations and N-body simulations Spectroscopic surveys in the Local Group Observational tests of dark matter models Predicted properties of first stars and SNe ...
... Comparisons between observations and N-body simulations Spectroscopic surveys in the Local Group Observational tests of dark matter models Predicted properties of first stars and SNe ...
0.1 Chapter 2
... well defined local temperature. This means that in the star there is a well defined temperature distribution. The local thermal equilibrium says something about the local temperature (that they are approximately the same), while TE says that there is no net change in energy; the same amount of energ ...
... well defined local temperature. This means that in the star there is a well defined temperature distribution. The local thermal equilibrium says something about the local temperature (that they are approximately the same), while TE says that there is no net change in energy; the same amount of energ ...
Microsoft Word
... reddened YSOs located/projected close to the molecular clump C2 is detected and are found to be younger than those located within the cluster core. The slope of the MF, Γ, derived from optical data, in the mass range 1.2
... reddened YSOs located/projected close to the molecular clump C2 is detected and are found to be younger than those located within the cluster core. The slope of the MF, Γ, derived from optical data, in the mass range 1.2
Chapter 16 Option E: ASTROPHYSICS
... local cluster is another cluster of galaxies, the Virgo cluster, which contains about a thousand galaxies. here are other clusters that can contain as many as ten thousand galaxies. Amazingly, all these diferent clusters are grouped into a socalled “super cluster”. Between these superclusters are va ...
... local cluster is another cluster of galaxies, the Virgo cluster, which contains about a thousand galaxies. here are other clusters that can contain as many as ten thousand galaxies. Amazingly, all these diferent clusters are grouped into a socalled “super cluster”. Between these superclusters are va ...
Galaxies - Stockton University
... • At the center of the Galaxy sits the nucleus. This is best seen at infrared and radio wavelengths which are less affected by dust than visual wavelengths. • In recent years high resolution observations of stars near the Galactic center at IR wavelengths have revealed high speed motions. – The inte ...
... • At the center of the Galaxy sits the nucleus. This is best seen at infrared and radio wavelengths which are less affected by dust than visual wavelengths. • In recent years high resolution observations of stars near the Galactic center at IR wavelengths have revealed high speed motions. – The inte ...
High-Resolution Spectroscopy of the Transiting Planet Host Star
... only reliable metrics that can be used in the comparison with theoretical isochrones. It is then crucial to provide an independent estimate of Tef f for an assessment of the validity of its spectroscopic value and uncertainty. To this end, we utilized the BVJHK apparent magnitudes to derive several ...
... only reliable metrics that can be used in the comparison with theoretical isochrones. It is then crucial to provide an independent estimate of Tef f for an assessment of the validity of its spectroscopic value and uncertainty. To this end, we utilized the BVJHK apparent magnitudes to derive several ...
Letter to the Editor ASTRONOMY ASTROPHYSICS
... of the material from which they have been formed. Although the computer models of the Antennae succesfully simulate the major features of this system, they do not reproduce the presence of gas condensations at the ends of the tidal tails. Numerical simulations of interacting galaxies predict density ...
... of the material from which they have been formed. Although the computer models of the Antennae succesfully simulate the major features of this system, they do not reproduce the presence of gas condensations at the ends of the tidal tails. Numerical simulations of interacting galaxies predict density ...
MACHOs
... Since our results for LMC7 was rather big, we decided to use very precise values to check our result. One of the main things we discovered was that instead of estimating the time interval, we noticed that the graph gave us a ...
... Since our results for LMC7 was rather big, we decided to use very precise values to check our result. One of the main things we discovered was that instead of estimating the time interval, we noticed that the graph gave us a ...
A new class of rapidly pulsating star
... there is a substantial Balmer jump observed in PB 8783. In order to include this extra information in the fitting, Planck functions were replaced by model atmospheres from Kurucz (1992) to represent Sl (Tl> v) and Sz(Tz, v). For the red star logg=4 models were used, while for the blue star logg=5 mo ...
... there is a substantial Balmer jump observed in PB 8783. In order to include this extra information in the fitting, Planck functions were replaced by model atmospheres from Kurucz (1992) to represent Sl (Tl> v) and Sz(Tz, v). For the red star logg=4 models were used, while for the blue star logg=5 mo ...
Evolution of supermassive stars as a pathway to black hole formation
... black holes in galactic nuclei. Because of their short nuclear burning timescales, such objects can be formed only when matter is able to accumulate at a rate exceeding ∼ 1M⊙ yr−1 . Here we revisit the structure and evolution of rotationally-stabilized supermassive stars, taking into account their c ...
... black holes in galactic nuclei. Because of their short nuclear burning timescales, such objects can be formed only when matter is able to accumulate at a rate exceeding ∼ 1M⊙ yr−1 . Here we revisit the structure and evolution of rotationally-stabilized supermassive stars, taking into account their c ...
News from high-mass twin stars
... The pomerons (wavy lines) couple to different quarks (solid lines) in quark matter (as in the hNJL Lagrangian) or to quarks in different baryons in nuclear matter (giving rise to repulsive 3- and 4- body interactions). ...
... The pomerons (wavy lines) couple to different quarks (solid lines) in quark matter (as in the hNJL Lagrangian) or to quarks in different baryons in nuclear matter (giving rise to repulsive 3- and 4- body interactions). ...
Winter Night Sky Guide
... 12. Moving to Orion’s right knee, you will see a bright, bluish star. This is Rigel and it is another type of supergiant, a blue supergiant naturally. Betelgeuse would have looked something like this before it started to run short on fuel. Like Betelgeuse, Rigel is much more massive than our Sun but ...
... 12. Moving to Orion’s right knee, you will see a bright, bluish star. This is Rigel and it is another type of supergiant, a blue supergiant naturally. Betelgeuse would have looked something like this before it started to run short on fuel. Like Betelgeuse, Rigel is much more massive than our Sun but ...
Word
... numbers in the boxes. Scientific notations such as 1e2 (=1x102 =100) and decimals are acceptable. Entering abnormal data including extremely large numbers and alphabets will result in program error and termination. The output updates itself only when the button “Plot” is pressed. If one or more data ...
... numbers in the boxes. Scientific notations such as 1e2 (=1x102 =100) and decimals are acceptable. Entering abnormal data including extremely large numbers and alphabets will result in program error and termination. The output updates itself only when the button “Plot” is pressed. If one or more data ...
Adiabatic evolution of mass-losing stars
... 3.2.2 Upper main-sequence stars Upper main-sequence stars have convective cores for more efficient energy transport (e.g. Woosley et al. 2002). This mixing of material around the core removes the helium ash from the hydrogen burning region, allowing more of the hydrogen in the star to be consumed du ...
... 3.2.2 Upper main-sequence stars Upper main-sequence stars have convective cores for more efficient energy transport (e.g. Woosley et al. 2002). This mixing of material around the core removes the helium ash from the hydrogen burning region, allowing more of the hydrogen in the star to be consumed du ...
Finding the aperture radius for photometry with SalsaJ Life Cycle of Stars
... star or galaxy by adding up all of the light from the object. For example, a star looks like a point of light when you look at it just with your eyes but the Earth’s atmosphere smears it out into something that looks like a round blob when you use a telescope to look at it. In order to measure the t ...
... star or galaxy by adding up all of the light from the object. For example, a star looks like a point of light when you look at it just with your eyes but the Earth’s atmosphere smears it out into something that looks like a round blob when you use a telescope to look at it. In order to measure the t ...
Document
... separation are nearly spherical. These are called detached binaries in which the stars evolve nearly independently. Most binaries are like this even when the stars have evolved to be red giants. In a close binary system if one star has expanded enough to fill the "figure-of-eight" contour then some ...
... separation are nearly spherical. These are called detached binaries in which the stars evolve nearly independently. Most binaries are like this even when the stars have evolved to be red giants. In a close binary system if one star has expanded enough to fill the "figure-of-eight" contour then some ...
- Net Start Class
... We use visual and radio telescopes to observe objects in space. Visual Telescopes are called refracting and reflecting. Reflecting telescopes use mirrors and refracting telescopes use lenses to view objects far away. Radio telescopes detect the different wavelengths of objects in space. When looked ...
... We use visual and radio telescopes to observe objects in space. Visual Telescopes are called refracting and reflecting. Reflecting telescopes use mirrors and refracting telescopes use lenses to view objects far away. Radio telescopes detect the different wavelengths of objects in space. When looked ...
Metal Abundances of Subdwarf B Stars from SPY
... discovered the helium deficiency of sdB stars for the first time. Peculiar metal abundances were reported. While some metals showed solar abundances, others were depleted or even enriched. Theoretical diffusion models yielded only little success. Radiative levitation and mass loss caused by stellar win ...
... discovered the helium deficiency of sdB stars for the first time. Peculiar metal abundances were reported. While some metals showed solar abundances, others were depleted or even enriched. Theoretical diffusion models yielded only little success. Radiative levitation and mass loss caused by stellar win ...
fact sheet about the Andromeda galaxy
... ANDROMEDA University of California Santa Cruz’s professor of Astronomy and Astrophysics, Raja GuhaThakurta, gives us the real info on the galaxy far, far away ...
... ANDROMEDA University of California Santa Cruz’s professor of Astronomy and Astrophysics, Raja GuhaThakurta, gives us the real info on the galaxy far, far away ...
Henriques B., White S., Lemson G., Thomas P., Guo Q., Marleau D
... Star formation, SN feedback, AGN feedback efficiency, Metals yield ...
... Star formation, SN feedback, AGN feedback efficiency, Metals yield ...
Chapter 9 Life and Times on the Main Sequence
... convection expected in the protostar during collapse to the main sequence. • The surface abundances are then assumed to have been undisturbed in the subsequent evolution, so that present surface abundances indicate the composition of the original solar core. • The abundance of most elements in the s ...
... convection expected in the protostar during collapse to the main sequence. • The surface abundances are then assumed to have been undisturbed in the subsequent evolution, so that present surface abundances indicate the composition of the original solar core. • The abundance of most elements in the s ...
form b - University of Iowa Astrophysics
... (b) Cepheid variables change their brightness too quickly to detect at great distances. (c) Most galaxies in the universe are elliptical and don’t have Cepheid variables. (d) The luminosity of SN Type Ia explosions is much greater than Cepheid variables. (e) Cepheid variables are not found in the mo ...
... (b) Cepheid variables change their brightness too quickly to detect at great distances. (c) Most galaxies in the universe are elliptical and don’t have Cepheid variables. (d) The luminosity of SN Type Ia explosions is much greater than Cepheid variables. (e) Cepheid variables are not found in the mo ...
Main sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or ""dwarf"" stars.After a star has formed, it generates thermal energy in the dense core region through the nuclear fusion of hydrogen atoms into helium. During this stage of the star's lifetime, it is located along the main sequence at a position determined primarily by its mass, but also based upon its chemical composition and other factors. All main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward pressure of gravitational collapse from the overlying layers. The strong dependence of the rate of energy generation in the core on the temperature and pressure helps to sustain this balance. Energy generated at the core makes its way to the surface and is radiated away at the photosphere. The energy is carried by either radiation or convection, with the latter occurring in regions with steeper temperature gradients, higher opacity or both.The main sequence is sometimes divided into upper and lower parts, based on the dominant process that a star uses to generate energy. Stars below about 1.5 times the mass of the Sun (or 1.5 solar masses (M☉)) primarily fuse hydrogen atoms together in a series of stages to form helium, a sequence called the proton–proton chain. Above this mass, in the upper main sequence, the nuclear fusion process mainly uses atoms of carbon, nitrogen and oxygen as intermediaries in the CNO cycle that produces helium from hydrogen atoms. Main-sequence stars with more than two solar masses undergo convection in their core regions, which acts to stir up the newly created helium and maintain the proportion of fuel needed for fusion to occur. Below this mass, stars have cores that are entirely radiative with convective zones near the surface. With decreasing stellar mass, the proportion of the star forming a convective envelope steadily increases, whereas main-sequence stars below 0.4 M☉ undergo convection throughout their mass. When core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.In general, the more massive a star is, the shorter its lifespan on the main sequence. After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram. The behavior of a star now depends on its mass, with stars below 0.23 M☉ becoming white dwarfs directly, whereas stars with up to ten solar masses pass through a red giant stage. More massive stars can explode as a supernova, or collapse directly into a black hole.