Where planets are formed: Protoplanetary disk evolution and planet
... Less than 10% of the embedded clusters survive longer than 10Myrs (Lada & Lada 2003) The large majority of stars spend the first 10Myrs of their life in a stellar cluster. ...
... Less than 10% of the embedded clusters survive longer than 10Myrs (Lada & Lada 2003) The large majority of stars spend the first 10Myrs of their life in a stellar cluster. ...
ppt
... (b) far away (Galactic) (c) really far away (extragalactic) (d) really, really far away (cosmological) ...
... (b) far away (Galactic) (c) really far away (extragalactic) (d) really, really far away (cosmological) ...
High Energy Processes in Young Stellar Objects
... • Successfully explains butterfly diagram • But fails when comes to fully convective situation ...
... • Successfully explains butterfly diagram • But fails when comes to fully convective situation ...
Tests and Constraints on Theories of Galaxy Formation and
... Requires that the total number of baryons turned into stars in the first 3% of the age of the universe be greater than or equal to the total number of baryons converted to stars in the remaining 97%. The metals produced by this conversion must be hidden in black holes. There must be no x-ray produci ...
... Requires that the total number of baryons turned into stars in the first 3% of the age of the universe be greater than or equal to the total number of baryons converted to stars in the remaining 97%. The metals produced by this conversion must be hidden in black holes. There must be no x-ray produci ...
Stellar Evolution
... as Distance Indicators Measuring a Cepheid’s period determine its absolute magnitude Distance ...
... as Distance Indicators Measuring a Cepheid’s period determine its absolute magnitude Distance ...
Parameters of a Strömgren Sphere Let`s assume that we have a
... whether the n = 2 term is a P or an S.) Thus, almost every recombination of a helium atom will produce another photon capable of ionizing hydrogen. Consequently, the effect of helium on the size of the Strömgren sphere is minor. (Note: some interesting physics is associated with the He I atom. Sinc ...
... whether the n = 2 term is a P or an S.) Thus, almost every recombination of a helium atom will produce another photon capable of ionizing hydrogen. Consequently, the effect of helium on the size of the Strömgren sphere is minor. (Note: some interesting physics is associated with the He I atom. Sinc ...
Laboratory Procedure (Word Format)
... It is easier to locate a celestial object if some prominent constellation or asterism can be found and used as a reference point. Ursa Major (the Big Dipper) serves as a good reference point for the north circumpolar constellations. Locate the Big Dipper. Begin with the star at the tip of the handle ...
... It is easier to locate a celestial object if some prominent constellation or asterism can be found and used as a reference point. Ursa Major (the Big Dipper) serves as a good reference point for the north circumpolar constellations. Locate the Big Dipper. Begin with the star at the tip of the handle ...
David S. Stevenson
... Initial ideas regarding the habitability of extrasolar planets have focused on the overall size of the planet and its location within the stellar habitable zone. However, many additional factors exist that affect their potential ability to harbor life. This is particularly true of planets orbiting r ...
... Initial ideas regarding the habitability of extrasolar planets have focused on the overall size of the planet and its location within the stellar habitable zone. However, many additional factors exist that affect their potential ability to harbor life. This is particularly true of planets orbiting r ...
Star-S_Teacher_Guide - The University of Texas at Dallas
... 2. How much bigger or smaller than the Sun is each star? How does your answer change if you compare volumes instead of diameters? This question provides a good opportunity to bring in mathematic concepts related to diameter and volume. ...
... 2. How much bigger or smaller than the Sun is each star? How does your answer change if you compare volumes instead of diameters? This question provides a good opportunity to bring in mathematic concepts related to diameter and volume. ...
4P38.pdf
... indicates that the Sun underwent a much more active phase in the past. The enhanced activity revealed itself in the form of strong high-energy emissions, frequent flares, and a powerful stellar wind. Such energy and particle environment certainly had an impact on the genesis and evolution of Solar S ...
... indicates that the Sun underwent a much more active phase in the past. The enhanced activity revealed itself in the form of strong high-energy emissions, frequent flares, and a powerful stellar wind. Such energy and particle environment certainly had an impact on the genesis and evolution of Solar S ...
Metal Abundances of Subdwarf B Stars from SPY
... constant iron abundances. Although the general pattern may be qualitatively explained in this way, some questions remain open. All observed trends are superimposed by a scatter from star to star. The abundance difference between stars with similar temperature can be as high as 2.0 dex for some elemen ...
... constant iron abundances. Although the general pattern may be qualitatively explained in this way, some questions remain open. All observed trends are superimposed by a scatter from star to star. The abundance difference between stars with similar temperature can be as high as 2.0 dex for some elemen ...
Tom Maccarone (Texas Tech University)
... Variability indicates that it is clearly a single object, and at this luminosity, it must be a black hole ...
... Variability indicates that it is clearly a single object, and at this luminosity, it must be a black hole ...
Supernovae
... Supernovae are spectacular events. One of the most researched supernovae - SN1987A - emitted light at a rate 100 million times that of the Sun and it was one of the fainter supernovae. They are stars in the later stages of stellar evolution that suddenly contract and then explode, increasing their e ...
... Supernovae are spectacular events. One of the most researched supernovae - SN1987A - emitted light at a rate 100 million times that of the Sun and it was one of the fainter supernovae. They are stars in the later stages of stellar evolution that suddenly contract and then explode, increasing their e ...
What`s in the Night Sky?
... be seen in the night sky because they reflect light from the sun back to Earth. Because the planets appear to wander across the night sky, they were named after the Greek word for “wanderer.” Eight planets orbit the sun in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and N ...
... be seen in the night sky because they reflect light from the sun back to Earth. Because the planets appear to wander across the night sky, they were named after the Greek word for “wanderer.” Eight planets orbit the sun in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and N ...
doc - EU-HOU
... You will fit your measurements by hand. In order to do this, iteratively change the 3 parameters W, T and Phi ( checking the fit (the red points and curve superimposed on the blue points) by eye after each iteration. It is also possible to find the best fit by minimising the “solver” value1 displ ...
... You will fit your measurements by hand. In order to do this, iteratively change the 3 parameters W, T and Phi ( checking the fit (the red points and curve superimposed on the blue points) by eye after each iteration. It is also possible to find the best fit by minimising the “solver” value1 displ ...
No Slide Title
... star formation and there are many bright stars.In the bulge there are many globular clusters. 5.M74-a photogenic spiral galaxy in Pisces.It is about 30 Mly away and has about 1011 stars. This is more or less how the Milky Way must look from outside.Picture taken with the Gemini North telescope on Ma ...
... star formation and there are many bright stars.In the bulge there are many globular clusters. 5.M74-a photogenic spiral galaxy in Pisces.It is about 30 Mly away and has about 1011 stars. This is more or less how the Milky Way must look from outside.Picture taken with the Gemini North telescope on Ma ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.