![Observational Overview](http://s1.studyres.com/store/data/016106543_1-7a9c1035e4b3211d2113e2c9e24d68e6-300x300.png)
Observational Overview
... DISK – thin compared to the diameter, thickness = 0.3 kpc and diameter = 25 kpc. Contains all raw material for making stars (huge clouds of molecular hydrogen and dust (tiny particles made of carbon and silicate)) and all the young stars, including Sun which is 8 kpc from centre. BULGE – contains o ...
... DISK – thin compared to the diameter, thickness = 0.3 kpc and diameter = 25 kpc. Contains all raw material for making stars (huge clouds of molecular hydrogen and dust (tiny particles made of carbon and silicate)) and all the young stars, including Sun which is 8 kpc from centre. BULGE – contains o ...
Cos. Won edu 2 - Adler Planetarium
... All stars are formed in nebulae, or clouds of gas and dust found scattered throughout galaxies. As the core of the new star forms, the amount of mass it contains determines the type of star it is. The Sun is considered a “main sequence” star. main sequence stars are at a point in their lifecycle whe ...
... All stars are formed in nebulae, or clouds of gas and dust found scattered throughout galaxies. As the core of the new star forms, the amount of mass it contains determines the type of star it is. The Sun is considered a “main sequence” star. main sequence stars are at a point in their lifecycle whe ...
Lecture - Ann Arbor Earth Science
... calculate it based on other observations. It can be determined either by the inertial properties of the body or by its gravitational influence on other bodies. The larger the mass, the stronger the gravitational effect on the bodies around it. Stellar masses are expressed as multiples of the mass of ...
... calculate it based on other observations. It can be determined either by the inertial properties of the body or by its gravitational influence on other bodies. The larger the mass, the stronger the gravitational effect on the bodies around it. Stellar masses are expressed as multiples of the mass of ...
Document
... calculate it based on other observations. It can be determined either by the inertial properties of the body or by its gravitational influence on other bodies. The larger the mass, the stronger the gravitational effect on the bodies around it. Stellar masses are expressed as multiples of the mass of ...
... calculate it based on other observations. It can be determined either by the inertial properties of the body or by its gravitational influence on other bodies. The larger the mass, the stronger the gravitational effect on the bodies around it. Stellar masses are expressed as multiples of the mass of ...
(HR) diagram - Cloudfront.net
... calculate it based on other observations. It can be determined either by the inertial properties of the body or by its gravitational influence on other bodies. The larger the mass, the stronger the gravitational effect on the bodies around it. Stellar masses are expressed as multiples of the mass of ...
... calculate it based on other observations. It can be determined either by the inertial properties of the body or by its gravitational influence on other bodies. The larger the mass, the stronger the gravitational effect on the bodies around it. Stellar masses are expressed as multiples of the mass of ...
WASP-7: The brightest transiting-exoplanet system in the Southern
... and Mg i b lines. An estimate of the microturbulence (ξt ) comes from several clean and unblended Fe i and Fe ii lines, while the ionization balance between Fe i and Fe ii was used as an additional diagnostic of Teff and log g. In addition to the spectral analysis, we have also used TYCHO, DENIS and ...
... and Mg i b lines. An estimate of the microturbulence (ξt ) comes from several clean and unblended Fe i and Fe ii lines, while the ionization balance between Fe i and Fe ii was used as an additional diagnostic of Teff and log g. In addition to the spectral analysis, we have also used TYCHO, DENIS and ...
The synthesis of organic and inorganic compounds in evolved stars
... feature at around 30 mm. This feature was first discovered in the spectra of carbon stars and PNe from the Kuiper Airborne Observatory (KAO) observations25. More recently, the 30-mm feature has been found to be common in carbon-rich PPNe, especially those showing the 21-mm emission feature26. The fa ...
... feature at around 30 mm. This feature was first discovered in the spectra of carbon stars and PNe from the Kuiper Airborne Observatory (KAO) observations25. More recently, the 30-mm feature has been found to be common in carbon-rich PPNe, especially those showing the 21-mm emission feature26. The fa ...
Life and Death of a Star
... rise dramatically – The Core begins to push back against Gravity and the Protostar is formed – The core is NOT yet hot enough for Fusion – However the seed of a new star is planted ...
... rise dramatically – The Core begins to push back against Gravity and the Protostar is formed – The core is NOT yet hot enough for Fusion – However the seed of a new star is planted ...
Document
... No direct images of other planetary systems so far Artist conception of planetary system orbiting around 55 Cancri using results of radial velocity Keck observations ...
... No direct images of other planetary systems so far Artist conception of planetary system orbiting around 55 Cancri using results of radial velocity Keck observations ...
HAYASHI LIMIT
... Let us make an approximation that convection begins at the photosphere, i.e. at T = Tef f , and let us replace stellar radius with the combination of effective temperature and luminosity according to ...
... Let us make an approximation that convection begins at the photosphere, i.e. at T = Tef f , and let us replace stellar radius with the combination of effective temperature and luminosity according to ...
Biography of a Star - Max-Planck
... For example, they had determined the masses of many stars; they knew their apparent and absolute (actual, independent of distance) brightnesses, their colors and surface temperatures, and their spectral types. In 1913, American Henry N. Russell (1877 to 1957) had the idea to check whether the differ ...
... For example, they had determined the masses of many stars; they knew their apparent and absolute (actual, independent of distance) brightnesses, their colors and surface temperatures, and their spectral types. In 1913, American Henry N. Russell (1877 to 1957) had the idea to check whether the differ ...
2.1 Hubble Space Telescope
... The Small Magellanic Cloud is roughly 200 000 light-years from Earth. Its proximity to us makes it an exceptional laboratory for performing in-depth studies of star formation processes and their evolution in an environment slightly different from our own Milky Way. Dwarf galaxies such as the Small M ...
... The Small Magellanic Cloud is roughly 200 000 light-years from Earth. Its proximity to us makes it an exceptional laboratory for performing in-depth studies of star formation processes and their evolution in an environment slightly different from our own Milky Way. Dwarf galaxies such as the Small M ...
The evolution of helium rich subdwarf B stars
... • Subdwarf B stars form the dominant population of faint blue blue stars (mB ~ 16) in our galaxy and giant elliptical galaxies • They are 0.5 MSun core helium-burning stars • Progenitors of White Dwarfs • Evolution has been the subject of much debate although evolution is though to play an important ...
... • Subdwarf B stars form the dominant population of faint blue blue stars (mB ~ 16) in our galaxy and giant elliptical galaxies • They are 0.5 MSun core helium-burning stars • Progenitors of White Dwarfs • Evolution has been the subject of much debate although evolution is though to play an important ...
Probing the first stars through the abundance of metal poor stars
... 3)Lack of surviving globular clusters that formed at high metallicity and high redshift 4) More rapid rise in the metallicity of cosmic gas than is predicted by current simulations 5) Enhancement in the abundances of α elements such as O and Mg at metallicities −2 [Fe/H] −0.5. ...
... 3)Lack of surviving globular clusters that formed at high metallicity and high redshift 4) More rapid rise in the metallicity of cosmic gas than is predicted by current simulations 5) Enhancement in the abundances of α elements such as O and Mg at metallicities −2 [Fe/H] −0.5. ...
Astronomy 110 Announcements: Life and Death of a Low Mass Star
... The star explodes Carbon fusion begins The core cools off Helium fuses in a shell around the core ...
... The star explodes Carbon fusion begins The core cools off Helium fuses in a shell around the core ...
Iron in Stars
... In a massive star (5 times the mass of the Sun or more), the evolution will follow a different track to that of the Sun. This is due to its size which allows for higher energies and pressures to be obtained at its core where the fusion takes place. After it has exhausted its fuel of hydrogen at the ...
... In a massive star (5 times the mass of the Sun or more), the evolution will follow a different track to that of the Sun. This is due to its size which allows for higher energies and pressures to be obtained at its core where the fusion takes place. After it has exhausted its fuel of hydrogen at the ...
CORALIE-ELODIE new planets and planetary systems. Looking for
... drifts due to environmental effects (temperature and pressure changes). After the introduction in the fiber paths of double-scrambling devices, the achieved precision for RV measurements is now of 8-10 ms- I . The ELODIE planet-search sample is magnitude-limited and consists of a 350 F-K dwarfs of t ...
... drifts due to environmental effects (temperature and pressure changes). After the introduction in the fiber paths of double-scrambling devices, the achieved precision for RV measurements is now of 8-10 ms- I . The ELODIE planet-search sample is magnitude-limited and consists of a 350 F-K dwarfs of t ...
The lifes of a star
... What happens when the supply of Helium is used up? The story is repeated: gravitational contraction takes over and the star collapses further. Eventually other nuclear reactions become viable, power increases until the various nuclei are depleted, then contraction takes over again. In this manner th ...
... What happens when the supply of Helium is used up? The story is repeated: gravitational contraction takes over and the star collapses further. Eventually other nuclear reactions become viable, power increases until the various nuclei are depleted, then contraction takes over again. In this manner th ...
PDF file
... You can see the partial eclipse. When planet passes in front of the star, it blocks some of the light of the star. (Just the geometrical fraction of the disk that it blocks, which can be around a percent). This GIVES the radius of the planet (why?) ...
... You can see the partial eclipse. When planet passes in front of the star, it blocks some of the light of the star. (Just the geometrical fraction of the disk that it blocks, which can be around a percent). This GIVES the radius of the planet (why?) ...
Pre-Main Sequence Evolution
... go into heating the gas, but disassociating the hydrogen. This means that the specific heat of the protostar is γ < 4/3, and, through the virial theorem, the star must collapse on a dynamical timescale. This collapse releases energy, which goes into further H2 disassociation (rather than heating the ...
... go into heating the gas, but disassociating the hydrogen. This means that the specific heat of the protostar is γ < 4/3, and, through the virial theorem, the star must collapse on a dynamical timescale. This collapse releases energy, which goes into further H2 disassociation (rather than heating the ...
Supernova scrutiny: Astronomers look inside the heart of a dying
... These observations have helped astronomers rule out previous theories about how stars explode, but NuSTAR’s measurements have also raised further questions. The astronomers found that the map of titanium-44 recorded by the telescope does not match up with the map of iron created by other telescopes ...
... These observations have helped astronomers rule out previous theories about how stars explode, but NuSTAR’s measurements have also raised further questions. The astronomers found that the map of titanium-44 recorded by the telescope does not match up with the map of iron created by other telescopes ...
Planetary nebula
![](https://commons.wikimedia.org/wiki/Special:FilePath/NGC6543.jpg?width=300)
A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula consisting of an expanding glowing shell of ionized gas ejected from old red giant stars late in their lives. The word ""nebula"" is Latin for mist or cloud and the term ""planetary nebula"" is a misnomer that originated in the 1780s with astronomer William Herschel because when viewed through his telescope, these objects appeared to him to resemble the rounded shapes of planets. Herschel's name for these objects was popularly adopted and has not been changed. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.A mechanism for formation of most planetary nebulae is thought to be the following: at the end of the star's life, during the red giant phase, the outer layers of the star are expelled by strong stellar winds. Eventually, after most of the red giant's atmosphere is dissipated, the exposed hot, luminous core emits ultraviolet radiation to ionize the ejected outer layers of the star. Absorbed ultraviolet light energises the shell of nebulous gas around the central star, appearing as a bright coloured planetary nebula at several discrete visible wavelengths.Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, the products of nucleosynthesis (such as carbon, nitrogen, oxygen and neon), have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances.In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies. About one-fifth are roughly spherical, but the majority are not spherically symmetric. The mechanisms which produce such a wide variety of shapes and features are not yet well understood, but binary central stars, stellar winds and magnetic fields may play a role.