Document
... Two GR correction terms (Rg/R): Yu.L.Vartanian (1972), Diss. For nonrotating stars. ...
... Two GR correction terms (Rg/R): Yu.L.Vartanian (1972), Diss. For nonrotating stars. ...
Interstellar Astrophysics Summary notes: Part 5
... the beginning of the track on the H-R diagram represents the point at which hydrostatic equilibrium begins to hold. For much of the initial collapse, energy is transported from the inner to outer regions of the protostar by convection, warming its surface. As the radius of the protostar decreases, t ...
... the beginning of the track on the H-R diagram represents the point at which hydrostatic equilibrium begins to hold. For much of the initial collapse, energy is transported from the inner to outer regions of the protostar by convection, warming its surface. As the radius of the protostar decreases, t ...
Goal: To understand how Saturn formed and what its core is
... • How? By using the Doppler effect! • When an object moves towards us, the wavelengths of light it emits (or sound on earth) decrease (because the object is closer to us when the wave finishes than when it starts • the shrink in the wave is the distance the object travels in the time it takes to mak ...
... • How? By using the Doppler effect! • When an object moves towards us, the wavelengths of light it emits (or sound on earth) decrease (because the object is closer to us when the wave finishes than when it starts • the shrink in the wave is the distance the object travels in the time it takes to mak ...
Star Arsenic, Star Selenium The Big Bang produced lots of hydrogen
... to determine the chemical makeup of stars, the origin of the elements, the ages of stars, and the evolution of galaxies and the Universe. This data is important in determining the best locations in which to look for habitable , extrasolar worlds. Now for the first time, astronomers have detected the ...
... to determine the chemical makeup of stars, the origin of the elements, the ages of stars, and the evolution of galaxies and the Universe. This data is important in determining the best locations in which to look for habitable , extrasolar worlds. Now for the first time, astronomers have detected the ...
No Slide Title
... If its companion is a main sequence or Red giant star then it can gain mass from its companion. Clump of mass has some small angular velocity. Law of conservation of angular momentummeans it moves faster and faster as it falls in. The infalling matter forms an accretion disc – a whirlpool like di ...
... If its companion is a main sequence or Red giant star then it can gain mass from its companion. Clump of mass has some small angular velocity. Law of conservation of angular momentummeans it moves faster and faster as it falls in. The infalling matter forms an accretion disc – a whirlpool like di ...
Lecture 6 - Stars and Distances
... matched his measurements onto Ptolemy’s magnitude groups and assigned a number for the magnitude of each star. ...
... matched his measurements onto Ptolemy’s magnitude groups and assigned a number for the magnitude of each star. ...
Stats talk - Harvard University
... Probing the evolution of stellar systems Andreas Zezas Harvard-Smithsonian Center for Astrophysics ...
... Probing the evolution of stellar systems Andreas Zezas Harvard-Smithsonian Center for Astrophysics ...
Astronomy C - Scioly.org
... 2. What group of stars is responsible for ionizing the central area of this DSO? 3. Which DSO is classified as a “hot Neptune” exoplanet? 4. What exciting compound was found in this exoplanet’s atmosphere (specify phase)? 5. One of the DSOs was the first brown dwarf discovered, in a binary system wi ...
... 2. What group of stars is responsible for ionizing the central area of this DSO? 3. Which DSO is classified as a “hot Neptune” exoplanet? 4. What exciting compound was found in this exoplanet’s atmosphere (specify phase)? 5. One of the DSOs was the first brown dwarf discovered, in a binary system wi ...
Lecture 02a: Setting a context for us in the Universe
... …but, they use it sparingly Tiny stars live very, very long times Tiny stars produce low energy radiation ...
... …but, they use it sparingly Tiny stars live very, very long times Tiny stars produce low energy radiation ...
1_Introduction
... Astronomers now know that stars are in clumps called “galaxies”. To find that out, they had to know how stars are distributed in 3-D. ...
... Astronomers now know that stars are in clumps called “galaxies”. To find that out, they had to know how stars are distributed in 3-D. ...
Characteristics of Stars PLATO
... • It takes a little over 8 minutes for light from out sun to reach Earth. • The light you see in the sky left the sun 8 minutes before you looked! • Light from other stars will take many years (Even Millions of years!) to reach us, so when you look at stars you are really looking into the past! ...
... • It takes a little over 8 minutes for light from out sun to reach Earth. • The light you see in the sky left the sun 8 minutes before you looked! • Light from other stars will take many years (Even Millions of years!) to reach us, so when you look at stars you are really looking into the past! ...
Poster - Arkansas Center for Space and Planetary Sciences
... other nearly edge-on from an observer’s viewpoint, the object’s variability results from the stars eclipsing each other and blocking some of the light. GX Gem belongs to a category of binary stars called close binaries since the two stars cannot be individually resolved in a telescope. By studying t ...
... other nearly edge-on from an observer’s viewpoint, the object’s variability results from the stars eclipsing each other and blocking some of the light. GX Gem belongs to a category of binary stars called close binaries since the two stars cannot be individually resolved in a telescope. By studying t ...
The sounds of the stars
... ost astronomers gaze at the heavens and see stars. William Chaplin hears an orchestra — a celestial symphony in which the smallest stars are flutes, the medium-sized ones are trombones and the giants are reverberating tubas. The sounds are internal vibrations that reveal themselves as a subtle, rhyt ...
... ost astronomers gaze at the heavens and see stars. William Chaplin hears an orchestra — a celestial symphony in which the smallest stars are flutes, the medium-sized ones are trombones and the giants are reverberating tubas. The sounds are internal vibrations that reveal themselves as a subtle, rhyt ...
The evolution of helium rich subdwarf B stars
... Position of He-sdB stars on the log g - Teff diagram with other subluminous stars ...
... Position of He-sdB stars on the log g - Teff diagram with other subluminous stars ...
Chapter 2 Cosmic tombstones
... Since the magnetic axis and the rotation axis are not aligned, the pulsar operates like a lighthouse an observer sees periodic pulses of radio emission According to the leading theory, this emission is produced by fast particles propagating along the magnetic field lines Particles are extracted fr ...
... Since the magnetic axis and the rotation axis are not aligned, the pulsar operates like a lighthouse an observer sees periodic pulses of radio emission According to the leading theory, this emission is produced by fast particles propagating along the magnetic field lines Particles are extracted fr ...
A star is born: understanding the physics of star formation
... acting to expand the cloud and those trying to collapse it (primarily gravity). However, if this equilibrium is perturbed, either by an external force, such as a supernova explosion, or by the cloud becoming sufficiently massive, the molecular cloud begins to undergo gravitational collapse. While th ...
... acting to expand the cloud and those trying to collapse it (primarily gravity). However, if this equilibrium is perturbed, either by an external force, such as a supernova explosion, or by the cloud becoming sufficiently massive, the molecular cloud begins to undergo gravitational collapse. While th ...
Northern Circumpolar Constellations
... of the other stars move in circular arcs throughout the night. ...
... of the other stars move in circular arcs throughout the night. ...
Evolved Massive Stars - University of Arizona
... bumps produced by Fe peak elements at ~70,000K and 250,000K • Without H envelope these temperatures occur near surface • Radiative acceleration out to sonic point of wind • Wind driven by continuum opacity instead of line opacity • Photosphere lies in optically thick wind ...
... bumps produced by Fe peak elements at ~70,000K and 250,000K • Without H envelope these temperatures occur near surface • Radiative acceleration out to sonic point of wind • Wind driven by continuum opacity instead of line opacity • Photosphere lies in optically thick wind ...
When you look up at the night sky, thousands of objects
... great amounts of energy; others emit less energy. Stars may be young, middleaged, old, or dying. They may be composed primarily of hydrogen, or they may contain mostly helium and heavier elements. Some are very bright; others are dimmer. Their colors range from blue and white to yellow and red. In t ...
... great amounts of energy; others emit less energy. Stars may be young, middleaged, old, or dying. They may be composed primarily of hydrogen, or they may contain mostly helium and heavier elements. Some are very bright; others are dimmer. Their colors range from blue and white to yellow and red. In t ...
ASTR-1020: Astronomy II Course Lecture Notes - Faculty
... We know this since one solar mass stars should last on the main sequence (see §III.C.) for 10 billion years and the Sun is currently 5 billion years old. As such, we have 5 billion more years before the Sun becomes a red giant, at which such time, it will “swallow” the most of the inner planets of t ...
... We know this since one solar mass stars should last on the main sequence (see §III.C.) for 10 billion years and the Sun is currently 5 billion years old. As such, we have 5 billion more years before the Sun becomes a red giant, at which such time, it will “swallow” the most of the inner planets of t ...
Слайд 1 - University of Wrocław
... Redshifted internal temperature becomes independent of r Then the equations of thermal evolution greatly simplify and reduce to the equation of global thermal balance: ...
... Redshifted internal temperature becomes independent of r Then the equations of thermal evolution greatly simplify and reduce to the equation of global thermal balance: ...
pdf of paper
... protons. Amazingly enough, another heliwn nucleus collides \\ith this shortlived target, leading to the formation of carbon. The process would seem about as likely as crossing a stream by stepping fleetingly on a log. A delicate match between the energies of helium, the unstable berylJium and the re ...
... protons. Amazingly enough, another heliwn nucleus collides \\ith this shortlived target, leading to the formation of carbon. The process would seem about as likely as crossing a stream by stepping fleetingly on a log. A delicate match between the energies of helium, the unstable berylJium and the re ...
File
... 1. the amount of elements present 2. temperature 3. density 4. pressure What percent of the sun’s mass is hydrogen? ...
... 1. the amount of elements present 2. temperature 3. density 4. pressure What percent of the sun’s mass is hydrogen? ...
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.