Nuclear Astrophysics
... Nuclear reaction rate: The reaction rate is proportional to the number density of particle species 1, the flux of particle species 2 that collide with 1, and the reaction cross section. Flux of N2 as seen by N1 : Flux of N1 as seen by N2 : ...
... Nuclear reaction rate: The reaction rate is proportional to the number density of particle species 1, the flux of particle species 2 that collide with 1, and the reaction cross section. Flux of N2 as seen by N1 : Flux of N1 as seen by N2 : ...
Matariki powerpoint
... All of a sudden disaster struck! The black net of Tataraimaka smacked the water, and all seven fishes were caught! The fishes cried and cried making the water salty with their tears. Tane the god of light was so sorry for the them that he snatched Tataraimaka’s net and hauled it up to the sky. Ther ...
... All of a sudden disaster struck! The black net of Tataraimaka smacked the water, and all seven fishes were caught! The fishes cried and cried making the water salty with their tears. Tane the god of light was so sorry for the them that he snatched Tataraimaka’s net and hauled it up to the sky. Ther ...
parallax in arc seconds
... System. Proxima Centauri has the largest known stellar parallax at 0.76”. ...
... System. Proxima Centauri has the largest known stellar parallax at 0.76”. ...
May 2015 - Hermanus Astronomy
... universe. Astronomers have found objects in the distant universe seen at a time when it was only 3 billion years old that could be precursors of the clusters seen around us today. Herschel revealed that the vast majority of Planck-detected foreground sources are consistent with dense concentrations ...
... universe. Astronomers have found objects in the distant universe seen at a time when it was only 3 billion years old that could be precursors of the clusters seen around us today. Herschel revealed that the vast majority of Planck-detected foreground sources are consistent with dense concentrations ...
Cosmic Distance Ladder
... • Different orbital positions of the Earth causes nearby stars to appear to move relative to the more distant stars. • The annual parallax is defined as the difference in position of a star as seen from the Earth and Sun, i.e. the angle subtended at a star by the mean radius of the Earth's orbit aro ...
... • Different orbital positions of the Earth causes nearby stars to appear to move relative to the more distant stars. • The annual parallax is defined as the difference in position of a star as seen from the Earth and Sun, i.e. the angle subtended at a star by the mean radius of the Earth's orbit aro ...
ASTR100 Class 01 - University of Maryland Department of
... channels, a few percent of the "snow" that you see on your screen is noise caused by the background of microwaves… ...
... channels, a few percent of the "snow" that you see on your screen is noise caused by the background of microwaves… ...
Stellar Evolution
... • “A planetary nebula is the glowing relic of a dying, sun-like star.” • “The hourglass shapes of many planetary nebulae are produced by the expansion of a ‘fast stellar wind’ within a slowly expanding ’cloud’ which is denser near its equator than its poles.” • If so, where do the x-rays come from? ...
... • “A planetary nebula is the glowing relic of a dying, sun-like star.” • “The hourglass shapes of many planetary nebulae are produced by the expansion of a ‘fast stellar wind’ within a slowly expanding ’cloud’ which is denser near its equator than its poles.” • If so, where do the x-rays come from? ...
Stellar Evolution
... Stellar Pulsations Estimate from sound travel time through the star: P ~ r-1/2 Cepheids all have approx. the same surface temperature. => Higher L => Larger R => Smaller r => Larger P ...
... Stellar Pulsations Estimate from sound travel time through the star: P ~ r-1/2 Cepheids all have approx. the same surface temperature. => Higher L => Larger R => Smaller r => Larger P ...
lecture_5_mbu_b
... The Carbon cycle (CNO cycle) also converts H to He but requires a C nucleus as a catalyst Requires temperatures >1.6x107K Occurs in Sun but minor compared to PPI More important fusion process for stellar masses >1.1M sun Since requires a C nucleus, only occurs in Pop I stars Second and fifth steps o ...
... The Carbon cycle (CNO cycle) also converts H to He but requires a C nucleus as a catalyst Requires temperatures >1.6x107K Occurs in Sun but minor compared to PPI More important fusion process for stellar masses >1.1M sun Since requires a C nucleus, only occurs in Pop I stars Second and fifth steps o ...
Sample pages 2 PDF
... whole volume of small clouds. Evans distinguished three stages of the evolution of massive cloud cores [1]. 1. At low temperature and high density the cloud begins to compress. The cloud density increases, but the temperature remains low at this stage. With growing density, the number of collisions ...
... whole volume of small clouds. Evans distinguished three stages of the evolution of massive cloud cores [1]. 1. At low temperature and high density the cloud begins to compress. The cloud density increases, but the temperature remains low at this stage. With growing density, the number of collisions ...
Abundances - Michigan State University
... to best reproduce all spectral features, incl. all absorption lines (can be 100’s or more) . Example for a r-process star (Sneden et al. ApJ 572 (2002) 861) ...
... to best reproduce all spectral features, incl. all absorption lines (can be 100’s or more) . Example for a r-process star (Sneden et al. ApJ 572 (2002) 861) ...
Sources of energy and the origin of the chemical elements
... Negative heat capacity causes star to increase in temperature as energy is lost through radiation to exterior. Virial condition implies ½ of Ugrav goes into internal heat energy, rest is radiated. When Tinterior reaches point where fusion can balance heat loss at surface, a static stable structure ( ...
... Negative heat capacity causes star to increase in temperature as energy is lost through radiation to exterior. Virial condition implies ½ of Ugrav goes into internal heat energy, rest is radiated. When Tinterior reaches point where fusion can balance heat loss at surface, a static stable structure ( ...
Astronomy.Practice.Quiz3
... 13. After the red giant phase, the next phase for a medium mass star is: a. nova b. planetary nebula c. white dwarf 14. This is how bright a star appears on Earth. a. apparent magnitude b. absolute magnitude ...
... 13. After the red giant phase, the next phase for a medium mass star is: a. nova b. planetary nebula c. white dwarf 14. This is how bright a star appears on Earth. a. apparent magnitude b. absolute magnitude ...
The Chandra Orion Ultradeep Project Eric Feigelson
... Some (but not all) flare loops are longer than seen in other stars, perhaps extending to the disk ...
... Some (but not all) flare loops are longer than seen in other stars, perhaps extending to the disk ...
Chapter 20
... fraction, a factor of 10 million, from about 10 trillion km across to about a million km across— that is, something initially larger than the whole Solar System collapses until most of its mass is in the form of a single star. During the contraction phase, a disk tends to form because the original n ...
... fraction, a factor of 10 million, from about 10 trillion km across to about a million km across— that is, something initially larger than the whole Solar System collapses until most of its mass is in the form of a single star. During the contraction phase, a disk tends to form because the original n ...
Cepheid variable stars
... Pulsating stars are a type of variable star in which brightness variations are caused by changes in the area and temperature of the star’s surface layers. Recent evidence suggests that all stars pulsate (if we measure them carefully enough), although the presence of concentrated populations of pulsa ...
... Pulsating stars are a type of variable star in which brightness variations are caused by changes in the area and temperature of the star’s surface layers. Recent evidence suggests that all stars pulsate (if we measure them carefully enough), although the presence of concentrated populations of pulsa ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.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.