Extragalactic Astrophysics 1 AA 2011-2012 Prof. LA Antonelli
... velocities with respect to Sun, and was indeed discovered from proper motions of nearby stars towards galactic center, we see stars going ahead and in the opposite direction stars remain behind, with respect to Sun. stars in the same galactocentric orbit as Sun have same velocity in absolute value, ...
... velocities with respect to Sun, and was indeed discovered from proper motions of nearby stars towards galactic center, we see stars going ahead and in the opposite direction stars remain behind, with respect to Sun. stars in the same galactocentric orbit as Sun have same velocity in absolute value, ...
A new low proper motion catalogue of bright M
... habitable zone as well as favourable contrast ratios between the planet and the host star. Though M dwarfs are the most numerous type of stars in the Galaxy, because of their colour and low luminosity they often can be confused for reddened stars or distant red giants. Because of this their identifi ...
... habitable zone as well as favourable contrast ratios between the planet and the host star. Though M dwarfs are the most numerous type of stars in the Galaxy, because of their colour and low luminosity they often can be confused for reddened stars or distant red giants. Because of this their identifi ...
black holes activity
... the time it get to 200,000 km out it is turned into energy and through convection transferred towards the surface C.What is Granulation? -Looking at the surface of the Sun it looks highly ________________ -Each granule is about 1000 km across, has a lifetime of __________________ and depending on it ...
... the time it get to 200,000 km out it is turned into energy and through convection transferred towards the surface C.What is Granulation? -Looking at the surface of the Sun it looks highly ________________ -Each granule is about 1000 km across, has a lifetime of __________________ and depending on it ...
Analemma - Stony Brook University
... Cepheus, and Cassiopeia are all to be found in the fall evening sky. • Perseus holds the head of Medusa (the variable star Algol - the Ghoul - is her eye). • As punishment for her vanity, Queen Cassiopeia, as a circumpolar constellation, is condemned to hang upside down half the year, a most undigni ...
... Cepheus, and Cassiopeia are all to be found in the fall evening sky. • Perseus holds the head of Medusa (the variable star Algol - the Ghoul - is her eye). • As punishment for her vanity, Queen Cassiopeia, as a circumpolar constellation, is condemned to hang upside down half the year, a most undigni ...
Hertzsprung-Russell Diagram Outline
... In 1911, Ejnar Hertzsprung investigated the relationship between luminosity and colors of stars in within clusters. ...
... In 1911, Ejnar Hertzsprung investigated the relationship between luminosity and colors of stars in within clusters. ...
Understanding the H-R Diagram
... 3,000°C). Look at the chart below and you will see that our Sun is a medium yellow star. A star's color is determined by its temperature. Red stars are cooler and blue stars are hotter. "The temperature of a star is determined by the mass it had when it formed and by its evolutionary stage (its "gro ...
... 3,000°C). Look at the chart below and you will see that our Sun is a medium yellow star. A star's color is determined by its temperature. Red stars are cooler and blue stars are hotter. "The temperature of a star is determined by the mass it had when it formed and by its evolutionary stage (its "gro ...
Stars part 1
... Detecting two or more lines of that element in the star’s spectrum indicates that element is present in that star. The brighter the spectral line, the greater amount of that element in the star. ...
... Detecting two or more lines of that element in the star’s spectrum indicates that element is present in that star. The brighter the spectral line, the greater amount of that element in the star. ...
The double-degenerate, super-Chandrasekhar nucleus of the
... system seems to have first undergone a phase of mass transfer via wind or stable Roche lobe overflow (RLOF), and then a CE. This is likely, as in order to have two oversized pre-WD stars with R=0.68-0.7 R⊙ still hot, the two events must have happened fast and consecutively. In addition, for the syst ...
... system seems to have first undergone a phase of mass transfer via wind or stable Roche lobe overflow (RLOF), and then a CE. This is likely, as in order to have two oversized pre-WD stars with R=0.68-0.7 R⊙ still hot, the two events must have happened fast and consecutively. In addition, for the syst ...
Stars and Planets - The University of Texas at Dallas
... Stars, like people, change as they age. While on the main sequence, a star’s color is directly related to its mass. Once a star runs out of hydrogen fuel in its core, however, everything changes! Stars will “evolve” off the main sequence with great changes in size, surface temperature, and luminosit ...
... Stars, like people, change as they age. While on the main sequence, a star’s color is directly related to its mass. Once a star runs out of hydrogen fuel in its core, however, everything changes! Stars will “evolve” off the main sequence with great changes in size, surface temperature, and luminosit ...
What Is A Spectrum?
... may have. The width of each spectral line can tell us how fast a material in a star is moving. A shift back and forth in the position of spectral lines can indicate that the star may be orbiting another star as well as be used to estimate the mass and size of a star. Lastly, an increase or decrease ...
... may have. The width of each spectral line can tell us how fast a material in a star is moving. A shift back and forth in the position of spectral lines can indicate that the star may be orbiting another star as well as be used to estimate the mass and size of a star. Lastly, an increase or decrease ...
pkt 14 Astrophysics
... Real spectra are more complicated than this (remember emission and absorption lines?) Stars can be arranged into categories based on the features in their spectra… How do we categorize stars? A few options: • by the “strength” (depth) of the absorption lines in their spectra • by their color as dete ...
... Real spectra are more complicated than this (remember emission and absorption lines?) Stars can be arranged into categories based on the features in their spectra… How do we categorize stars? A few options: • by the “strength” (depth) of the absorption lines in their spectra • by their color as dete ...
Understanding Stars
... Fill in the missing values on the table below and plot the temperature and luminosities on the class diagram when you're finished. (Make sure you give the temperature in Kelvins, not T Sun.) Try to distribute the work so each group member is responsible for one star – and if you have more stars than ...
... Fill in the missing values on the table below and plot the temperature and luminosities on the class diagram when you're finished. (Make sure you give the temperature in Kelvins, not T Sun.) Try to distribute the work so each group member is responsible for one star – and if you have more stars than ...
Topic 2 Chemical Composition of Stars
... (by mass) There is a deep minimum in the abundance curve corresponding to Li, Be, B This is followed by a peak around C,N,O,Ne Then there is a further decline until the next peak at Fe Abundances generally diminish until A = 100 and Z = 45 after which the curve flattens out Some stars have considera ...
... (by mass) There is a deep minimum in the abundance curve corresponding to Li, Be, B This is followed by a peak around C,N,O,Ne Then there is a further decline until the next peak at Fe Abundances generally diminish until A = 100 and Z = 45 after which the curve flattens out Some stars have considera ...
Chapter 6 Stars
... from the life cycle of a low-mass or medium-mass star. High-mass stars quickly evolve into brilliant supergiants. When a supergiant runs out of fuel, it can explode suddenly. Within hours, the star blazes millions of times brighter. The explosion is called a supernova. After a supernova, some of th ...
... from the life cycle of a low-mass or medium-mass star. High-mass stars quickly evolve into brilliant supergiants. When a supergiant runs out of fuel, it can explode suddenly. Within hours, the star blazes millions of times brighter. The explosion is called a supernova. After a supernova, some of th ...
Comprehensive Census and Complete Characterization of Nearby
... corresponding to within 200 pc. These stars cross-correlated with the AllWISE catalog using a five arc second search radius returned over 513,000 stars. A number of further criteria were implemented to ensure high quality photometry for SED fitting, that we can eliminate as many giants as possible sin ...
... corresponding to within 200 pc. These stars cross-correlated with the AllWISE catalog using a five arc second search radius returned over 513,000 stars. A number of further criteria were implemented to ensure high quality photometry for SED fitting, that we can eliminate as many giants as possible sin ...
1 Stars
... The stars that make up a constellation appear close to each other from Earth. In reality, they may be very distant from one another. Constellations were important to people, like the Ancient Greeks. People who spent a lot of time outdoors at night, like shepherds, named them and told stories about t ...
... The stars that make up a constellation appear close to each other from Earth. In reality, they may be very distant from one another. Constellations were important to people, like the Ancient Greeks. People who spent a lot of time outdoors at night, like shepherds, named them and told stories about t ...
Lect15-3-23-11-stars..
... energy that escaped from the surface of the core with heat energy generated in the collapse from release of gravitational potential energy. But this cannot be true, since the collapse makes the core smaller. The core’s mass is still the same, but now its smaller size means that its gravity is strong ...
... energy that escaped from the surface of the core with heat energy generated in the collapse from release of gravitational potential energy. But this cannot be true, since the collapse makes the core smaller. The core’s mass is still the same, but now its smaller size means that its gravity is strong ...
26.2 Stars - Clinton Public Schools
... The Hertzsprung-Russell Diagram Giants and Dwarfs In general, two factors determine a star’s absolute brightness: its size and its surface temperature. An H-R diagram shows a star’s absolute brightness and surface temperature. • If you compare two stars at the same temperature, the brighter one must ...
... The Hertzsprung-Russell Diagram Giants and Dwarfs In general, two factors determine a star’s absolute brightness: its size and its surface temperature. An H-R diagram shows a star’s absolute brightness and surface temperature. • If you compare two stars at the same temperature, the brighter one must ...
on the mass distribution of stars in the solar neighbourhood
... After accepting the final results one meets the question how reliable they are. Here we have three main items to consider. The first concerns the fraction of low-mass stars because if it is not so high, as found in this paper, then the present results become doubtful. A comparison can be done with I ...
... After accepting the final results one meets the question how reliable they are. Here we have three main items to consider. The first concerns the fraction of low-mass stars because if it is not so high, as found in this paper, then the present results become doubtful. A comparison can be done with I ...
white dwarfs, neutron stars, black hole
... degeneracy pressure and gravity. Electron degeneracy pressure does not depend on temperature and thus the size of the brown dwarf will stay the same as it cools down. Electron degeneracy pressure is a quantum mechanical effect that comes into play at high densities. Just as electrons in an atom can ...
... degeneracy pressure and gravity. Electron degeneracy pressure does not depend on temperature and thus the size of the brown dwarf will stay the same as it cools down. Electron degeneracy pressure is a quantum mechanical effect that comes into play at high densities. Just as electrons in an atom can ...
chapter16StarBirth
... • Without CO molecules to provide cooling, the clouds that formed the first stars had to be considerably warmer than today’s molecular clouds • The first stars must therefore have been more massive than most of today’s stars, for gravity to overcome pressure ...
... • Without CO molecules to provide cooling, the clouds that formed the first stars had to be considerably warmer than today’s molecular clouds • The first stars must therefore have been more massive than most of today’s stars, for gravity to overcome pressure ...
The physics of white dwarfs
... dominated by the strong Balmer absorption lines of hydrogen. At higher temperatures most of the hydrogen becomes ionized, causing the Balmer lines to weaken; stars with Te(c > 15 000 K are characterized by strong absorption lines of helium, the second most abundant element, which is less easily ioni ...
... dominated by the strong Balmer absorption lines of hydrogen. At higher temperatures most of the hydrogen becomes ionized, causing the Balmer lines to weaken; stars with Te(c > 15 000 K are characterized by strong absorption lines of helium, the second most abundant element, which is less easily ioni ...
Stars change over their life cycles.
... than the Sun. If Betelgeuse replaced the Sun, it would fill space in our solar system well beyond Earth’s orbit. Because giant and supergiant stars have such huge surface areas to give off light, they are very bright. Betelgeuse is one of the brightest stars in the sky, even though it is 522 light-y ...
... than the Sun. If Betelgeuse replaced the Sun, it would fill space in our solar system well beyond Earth’s orbit. Because giant and supergiant stars have such huge surface areas to give off light, they are very bright. Betelgeuse is one of the brightest stars in the sky, even though it is 522 light-y ...
charts_set_9
... Composition unknown. Probably mostly exotic particles that hardly interact with ordinary matter at all (except gravity). Small fraction may be brown dwarfs, dead white dwarfs. Most likely it's a dark halo surrounding the Milky Way. ...
... Composition unknown. Probably mostly exotic particles that hardly interact with ordinary matter at all (except gravity). Small fraction may be brown dwarfs, dead white dwarfs. Most likely it's a dark halo surrounding the Milky Way. ...
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.