star
... Low- and Medium-Mass Stars Low-mass and medium-mass stars, which can be as much as eight times as massive as the sun, eventually turn into white dwarfs. • Stars remain in the giant stage until their hydrogen and helium supplies dwindle and there are no other elements to fuse. • The energy coming fro ...
... Low- and Medium-Mass Stars Low-mass and medium-mass stars, which can be as much as eight times as massive as the sun, eventually turn into white dwarfs. • Stars remain in the giant stage until their hydrogen and helium supplies dwindle and there are no other elements to fuse. • The energy coming fro ...
Determination of kinetic energies of stars using Hipparcos data *
... distribution of kinetic energies but not velocities, unlike the situation with molecules of gas. The difference between stellar gas and the gas in thermodynamics lies in the way the energies interchange: the elastic collisions are the reason of energy interchange in the “usual” gas, whereas it is ap ...
... distribution of kinetic energies but not velocities, unlike the situation with molecules of gas. The difference between stellar gas and the gas in thermodynamics lies in the way the energies interchange: the elastic collisions are the reason of energy interchange in the “usual” gas, whereas it is ap ...
http://www.highpoint.edu/~afuller/PHY-1050
... • High-mass stars with >8 Msun have short lives, eventually becoming hot enough to make iron, and end in supernova explosions. • Low-mass stars with <2 Msun have long lives, never become hot enough to fuse carbon nuclei, and end as white dwarfs. • Intermediate-mass stars can make elements heavier th ...
... • High-mass stars with >8 Msun have short lives, eventually becoming hot enough to make iron, and end in supernova explosions. • Low-mass stars with <2 Msun have long lives, never become hot enough to fuse carbon nuclei, and end as white dwarfs. • Intermediate-mass stars can make elements heavier th ...
Sternentstehung - Star Formation
... Massive Star Formation - Why important? - Although few in numbers, LM3 they inject significant amounts of energy into ISM during their lifetime (outflows, radiation, supernovae). - They produce all the heavy elements. - Low-mass star formation is strongly influenced by massive stars. - Massive sta ...
... Massive Star Formation - Why important? - Although few in numbers, LM3 they inject significant amounts of energy into ISM during their lifetime (outflows, radiation, supernovae). - They produce all the heavy elements. - Low-mass star formation is strongly influenced by massive stars. - Massive sta ...
How Many Stars in the Sky?
... age. Stars vary in brightness, color, mass, temperature, and age. Stars are classified by colors as related to their surface temperature. The coolest stars are orange, then red, yellow, green, blue and finally blue-white. The size of a star on a photograph tells us about its brightness. Large star ...
... age. Stars vary in brightness, color, mass, temperature, and age. Stars are classified by colors as related to their surface temperature. The coolest stars are orange, then red, yellow, green, blue and finally blue-white. The size of a star on a photograph tells us about its brightness. Large star ...
Chapter 2 Surveying the stars 2.1 Star magnitudes
... gravitational attraction. Galaxies are millions of light years apart, separated from one another by empty space. The most distant galaxies are about ten thousand million light years away and were formed shortly after the Big Bang. The Universe is thought to be about 13 thousand million (i.e. 13 bill ...
... gravitational attraction. Galaxies are millions of light years apart, separated from one another by empty space. The most distant galaxies are about ten thousand million light years away and were formed shortly after the Big Bang. The Universe is thought to be about 13 thousand million (i.e. 13 bill ...
Big Bang Theory
... other galaxies and eventually helped to support the Big Bang theory of the origin of the universe. In the Big Bang Theory – Hubble’s Law Gizmo™, select Region A. Look at the image of the Andromeda Galaxy, a galaxy relatively close to our own Milky Way galaxy. 1. Locate the two Cepheid variables, the ...
... other galaxies and eventually helped to support the Big Bang theory of the origin of the universe. In the Big Bang Theory – Hubble’s Law Gizmo™, select Region A. Look at the image of the Andromeda Galaxy, a galaxy relatively close to our own Milky Way galaxy. 1. Locate the two Cepheid variables, the ...
supernova remnants: a link between massive stars and the
... that when the NS forms, the new star overshoots its equilibrium configuration giving a large compression to the neutron core (the core collapses in about 1 sec). This produces a rebound that sends a strong supersonic shock wave in about 0.01 sec that travels through the infalling matter. In a short ...
... that when the NS forms, the new star overshoots its equilibrium configuration giving a large compression to the neutron core (the core collapses in about 1 sec). This produces a rebound that sends a strong supersonic shock wave in about 0.01 sec that travels through the infalling matter. In a short ...
Ch 11a (Measuring Stars 10-28-10)
... inverse square of the distance (brightness proportional to 1/d2). If we know the apparent brightness and the distance to a star we can calculate its absolute (intrinsic) brightness: apparent brightness = (absolute brightness)/d2 Luminosity (energy/sec) is equivalent to absolute brightness L= 4R2 ...
... inverse square of the distance (brightness proportional to 1/d2). If we know the apparent brightness and the distance to a star we can calculate its absolute (intrinsic) brightness: apparent brightness = (absolute brightness)/d2 Luminosity (energy/sec) is equivalent to absolute brightness L= 4R2 ...
17_LectureOutline
... In order to measure stellar masses in a binary star, the period and semimajor axis of the orbit must be measured. Once this is done, Kepler’s third law gives the sum of the masses of the two stars. Then the relative speeds of the two stars can be measured using the Doppler effect; the speed will be ...
... In order to measure stellar masses in a binary star, the period and semimajor axis of the orbit must be measured. Once this is done, Kepler’s third law gives the sum of the masses of the two stars. Then the relative speeds of the two stars can be measured using the Doppler effect; the speed will be ...
Astronomy 112: The Physics of Stars Class 19 Notes: The Stellar
... using stars as observed by the Hubble Space Telescope. They then tried to find a star formation history that would reproduce the observed HR diagram. [Slides 4-6 – star formation history in NGC 2976 inferred by Williams et al. using stellar population synthesis] This is one example of stellar popula ...
... using stars as observed by the Hubble Space Telescope. They then tried to find a star formation history that would reproduce the observed HR diagram. [Slides 4-6 – star formation history in NGC 2976 inferred by Williams et al. using stellar population synthesis] This is one example of stellar popula ...
The Sun and Stars
... Other stars have A star with orbiting planets is called a planetary system. Until the planetary last decade, no one knew whether planets were commonly formed with systems stars or whether solar systems like our own were rare. However, as of this writing, more than 150 planets have been discovered ar ...
... Other stars have A star with orbiting planets is called a planetary system. Until the planetary last decade, no one knew whether planets were commonly formed with systems stars or whether solar systems like our own were rare. However, as of this writing, more than 150 planets have been discovered ar ...
Document
... there are several another populations (Giant, supergiant , white dwarfs). • Giant stars are stars in the late stage of the evolution. • White dwarfs are end stage of the low mass star. • After main sequence phase, how do star evolve? ...
... there are several another populations (Giant, supergiant , white dwarfs). • Giant stars are stars in the late stage of the evolution. • White dwarfs are end stage of the low mass star. • After main sequence phase, how do star evolve? ...
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... (From http://www.angelfire.com/sc2/Trunko/starsh1.JPG) ...
... (From http://www.angelfire.com/sc2/Trunko/starsh1.JPG) ...
Astronomy 112: The Physics of Stars Class 15 Notes: Stars Before
... the one I just showed can be made. In addition to this molecular line, there are many more that we can use, involving both different transitions of CO and of other molecules – thousands have been detected. These clouds are extremely cold, typically around 10 K, mainly because the CO molecules are v ...
... the one I just showed can be made. In addition to this molecular line, there are many more that we can use, involving both different transitions of CO and of other molecules – thousands have been detected. These clouds are extremely cold, typically around 10 K, mainly because the CO molecules are v ...
26.2 Stars - Clinton Public Schools
... 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 be larger. • Hotter stars are b ...
... 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 be larger. • Hotter stars are b ...
Star
A star is a luminous sphere of plasma held together by its own gravity. The nearest star to Earth is the Sun. Other stars are visible from Earth during the night, appearing as a multitude of fixed luminous points in the sky due to their immense distance from Earth. Historically, the most prominent stars were grouped into constellations and asterisms, and the brightest stars gained proper names. Extensive catalogues of stars have been assembled by astronomers, which provide standardized star designations.For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen into helium in its core, releasing energy that traverses the star's interior and then radiates into outer space. Once the hydrogen in the core of a star is nearly exhausted, almost all naturally occurring elements heavier than helium are created by stellar nucleosynthesis during the star's lifetime and, for some stars, by supernova nucleosynthesis when it explodes. Near the end of its life, a star can also contain degenerate matter. Astronomers can determine the mass, age, metallicity (chemical composition), and many other properties of a star by observing its motion through space, luminosity, and spectrum respectively. The total mass of a star is the principal determinant of its evolution and eventual fate. Other characteristics of a star, including diameter and temperature, change over its life, while the star's environment affects its rotation and movement. A plot of the temperature of many stars against their luminosities, known as a Hertzsprung–Russell diagram (H–R diagram), allows the age and evolutionary state of a star to be determined.A star's life begins with the gravitational collapse of a gaseous nebula of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Once the stellar core is sufficiently dense, hydrogen becomes steadily converted into helium through nuclear fusion, releasing energy in the process. The remainder of the star's interior carries energy away from the core through a combination of radiative and convective processes. The star's internal pressure prevents it from collapsing further under its own gravity. Once the hydrogen fuel at the core is exhausted, a star with at least 0.4 times the mass of the Sun expands to become a red giant, in some cases fusing heavier elements at the core or in shells around the core. The star then evolves into a degenerate form, recycling a portion of its matter into the interstellar environment, where it will contribute to the formation of a new generation of stars with a higher proportion of heavy elements. Meanwhile, the core becomes a stellar remnant: a white dwarf, a neutron star, or (if it is sufficiently massive) a black hole.Binary and multi-star systems consist of two or more stars that are gravitationally bound, and generally move around each other in stable orbits. When two such stars have a relatively close orbit, their gravitational interaction can have a significant impact on their evolution. Stars can form part of a much larger gravitationally bound structure, such as a star cluster or a galaxy.