PRESS 2001 Project Report - Hong Kong University of Science and
... 1. Introduction [1] Half or more of all stars in the universe are in orbit around another star or stars. In most of these multiple-star systems, there is a type of system which consists of two stars only, known as a binary star system, whose components may be separated by a large fraction of a light ...
... 1. Introduction [1] Half or more of all stars in the universe are in orbit around another star or stars. In most of these multiple-star systems, there is a type of system which consists of two stars only, known as a binary star system, whose components may be separated by a large fraction of a light ...
Determining Distances to Other Galaxies
... If stars in the disk of a spiral galaxy are on slightly eccentric orbits, and the position angle of these ellipses vary with radius, a spiral-shaped density wave can be formed from a set of nested ovals. Density wave theory is really based on the premise that mutual gravitational attraction of stars ...
... If stars in the disk of a spiral galaxy are on slightly eccentric orbits, and the position angle of these ellipses vary with radius, a spiral-shaped density wave can be formed from a set of nested ovals. Density wave theory is really based on the premise that mutual gravitational attraction of stars ...
DTU_9e_ch15
... This map, based on radio telescope surveys of 21-cm radiation, shows the distribution of hydrogen gas in a face-on view of the Galaxy. This view just hints at spiral structure. The galactic nucleus is marked with a dot surrounded by a circle. Details in the large, blank, wedge-shaped region toward t ...
... This map, based on radio telescope surveys of 21-cm radiation, shows the distribution of hydrogen gas in a face-on view of the Galaxy. This view just hints at spiral structure. The galactic nucleus is marked with a dot surrounded by a circle. Details in the large, blank, wedge-shaped region toward t ...
Star Formation in the Local Milky Way
... According to the theory of stellar structure and evolution, once formed the subsequent life history of a star is entirely predetermined by the only two parameters: the star’s initial mass and, to a lesser extent, its chemical composition. The frequency distribution of stellar masses at birth, or the ...
... According to the theory of stellar structure and evolution, once formed the subsequent life history of a star is entirely predetermined by the only two parameters: the star’s initial mass and, to a lesser extent, its chemical composition. The frequency distribution of stellar masses at birth, or the ...
WELCOME TO THE MILKY WAY
... galaxy contains the spiral arms, which are very rich in gas and dust. These spiral arms are about 1,500 ly thick. They also contain the emission nebulae and the young and hot (O and B) giant and supergiant stars that light up the spiral structure (see Fig. 2.1). The Milky Way is surrounded by a halo ...
... galaxy contains the spiral arms, which are very rich in gas and dust. These spiral arms are about 1,500 ly thick. They also contain the emission nebulae and the young and hot (O and B) giant and supergiant stars that light up the spiral structure (see Fig. 2.1). The Milky Way is surrounded by a halo ...
1 Introduction - University of Amsterdam
... compact helium core is revealed it is identified as a Wolf-Rayet star. The supernova progenitor state (at the top of the diagram) determines the characteristics of the final explosion and therefore also the nature of the compact object that is left behind. It is not only mass that governs the evolut ...
... compact helium core is revealed it is identified as a Wolf-Rayet star. The supernova progenitor state (at the top of the diagram) determines the characteristics of the final explosion and therefore also the nature of the compact object that is left behind. It is not only mass that governs the evolut ...
Stars, Galaxies, and the Universe Section 1
... • Binary stars are pairs of stars that revolve around each other and are held together by gravity. The center of mass, or barycenter, is somewhere between the two stars. • In star systems that have more than two stars, two stars may revolve rapidly around a common barycenter, while a third star revo ...
... • Binary stars are pairs of stars that revolve around each other and are held together by gravity. The center of mass, or barycenter, is somewhere between the two stars. • In star systems that have more than two stars, two stars may revolve rapidly around a common barycenter, while a third star revo ...
Ardua et Astra: On the Calculation of the Dates of the Rising and
... It is often helpful to know when these phenomena actually took place; and in some cases, such as Ovid’s Fasti, it can inform both textual and literary criticism. In the Fasti Ovid provides over forty dates for the rising and setting of various stars and constellations, following the tradition of the ...
... It is often helpful to know when these phenomena actually took place; and in some cases, such as Ovid’s Fasti, it can inform both textual and literary criticism. In the Fasti Ovid provides over forty dates for the rising and setting of various stars and constellations, following the tradition of the ...
Science performance of Gaia, ESA`s space
... • Gaia will detect tens of thousands of brown dwarfs, both drifting through space in isolation and in orbit around other stars (Haywood and Jordi 2002). This data is vital for investigating the physics of star formation since brown dwarfs represent stars that “just did not make it” to core hydrogen ...
... • Gaia will detect tens of thousands of brown dwarfs, both drifting through space in isolation and in orbit around other stars (Haywood and Jordi 2002). This data is vital for investigating the physics of star formation since brown dwarfs represent stars that “just did not make it” to core hydrogen ...
Astronomy Astrophysics NGC 7419 as a template for red supergiant clusters &
... spectroscopy around the Hα line for most of the candidate Be stars, confirming their nature. A second peculiarity of NGC 7419 is the presence of five red supergiants (RSGs) as confirmed radial velocity members of the cluster (Beauchamp et al. 1994). Until recently, this was the highest number of RSG ...
... spectroscopy around the Hα line for most of the candidate Be stars, confirming their nature. A second peculiarity of NGC 7419 is the presence of five red supergiants (RSGs) as confirmed radial velocity members of the cluster (Beauchamp et al. 1994). Until recently, this was the highest number of RSG ...
Test Ch. 27 Multiple Choice Identify the choice that best completes
... 25. In the last stage of stellar evolution following a supernova, stars too massive to form neutron stars may form a A. black dwarf. B. red supergiant. C. white dwarf. D. black hole. 26. In which stage of stellar evolution does combined hydrogen fusion and helium fusion cause a star’s outer shell to ...
... 25. In the last stage of stellar evolution following a supernova, stars too massive to form neutron stars may form a A. black dwarf. B. red supergiant. C. white dwarf. D. black hole. 26. In which stage of stellar evolution does combined hydrogen fusion and helium fusion cause a star’s outer shell to ...
The Milky Way and other Galaxies
... Infer mass in the very center Central black holes! Several million, up to more than a billion solar masses! Supermassive black holes ...
... Infer mass in the very center Central black holes! Several million, up to more than a billion solar masses! Supermassive black holes ...
15-3 Notes: Galaxies
... of sizes and shapes. The largest galaxies contain more than a trillion stars. Astronomers classify a galaxy as a spiral, elliptical, or irregular galaxy according to its shape. Spiral galaxies, such as the Andromeda galaxy, have a bulge at the center and spiral arms. The spiral arms are made up of g ...
... of sizes and shapes. The largest galaxies contain more than a trillion stars. Astronomers classify a galaxy as a spiral, elliptical, or irregular galaxy according to its shape. Spiral galaxies, such as the Andromeda galaxy, have a bulge at the center and spiral arms. The spiral arms are made up of g ...
star
... and dust to form new stars. They are spherical and have a dense concentration of stars in the center. Globular clusters can contain more than a million stars. Globular clusters usually do not have short-lived blue stars because these stars have already died out. Astronomers estimate that the oldest ...
... and dust to form new stars. They are spherical and have a dense concentration of stars in the center. Globular clusters can contain more than a million stars. Globular clusters usually do not have short-lived blue stars because these stars have already died out. Astronomers estimate that the oldest ...
Chapter 15: The Milky Way Galaxy
... WHAT DO YOU THINK? How many stars does the Milky Way Galaxy contain? Where is our Solar System located in the Milky Way Galaxy? Is the Sun moving through the Milky Way Galaxy and, if so, about how fast? ...
... WHAT DO YOU THINK? How many stars does the Milky Way Galaxy contain? Where is our Solar System located in the Milky Way Galaxy? Is the Sun moving through the Milky Way Galaxy and, if so, about how fast? ...
Chapter 12: Stars and Galaxies
... based on luminosity and temperature. Two of these star groupings lie above the main sequence line. The group closest to the main sequence has large-diameter stars with lower temperatures. They are called red giants. The stars in the group at the top of an H-R diagram are very large and have varying ...
... based on luminosity and temperature. Two of these star groupings lie above the main sequence line. The group closest to the main sequence has large-diameter stars with lower temperatures. They are called red giants. The stars in the group at the top of an H-R diagram are very large and have varying ...
chapter 24 instructor notes
... tables (magnitude, parallax), which were simple to use with experience. For each value of m, the entries reach a maximum at some value of log k. The summation of the entries for each column gives the values for the predicted counts. The values can be compared with actual star counts in a particular ...
... tables (magnitude, parallax), which were simple to use with experience. For each value of m, the entries reach a maximum at some value of log k. The summation of the entries for each column gives the values for the predicted counts. The values can be compared with actual star counts in a particular ...
PPT presentation
... Contamination of the PN samples The contamination increases with distance to the galaxy. It is negligible for distances < 10 Mpc, as we just saw. At the distance of the Virgo cluster the luminosity function of the contaminants imitates the PNLF of a low-surfacedensity PN population at that distance ...
... Contamination of the PN samples The contamination increases with distance to the galaxy. It is negligible for distances < 10 Mpc, as we just saw. At the distance of the Virgo cluster the luminosity function of the contaminants imitates the PNLF of a low-surfacedensity PN population at that distance ...
2_ISM - UCT Astronomy Department
... •interrupted by local maximum - the so-called 2175-Angstrom bump ...
... •interrupted by local maximum - the so-called 2175-Angstrom bump ...
Galaxies - Mike Brotherton
... Infer mass in the very center Central black holes! Several million, up to more than a billion solar masses! Supermassive black holes ...
... Infer mass in the very center Central black holes! Several million, up to more than a billion solar masses! Supermassive black holes ...
Chapter 26: Stars, Galaxies, and the Universe Stars
... Stars are made mostly of hydrogen and helium. These are both very lightweight gases. However, there is so much hydrogen and helium in a star that the weight of these gases is enormous. In the center of a star, the pressure is great enough to heat the gases and cause nuclear fusion reactions. In a nu ...
... Stars are made mostly of hydrogen and helium. These are both very lightweight gases. However, there is so much hydrogen and helium in a star that the weight of these gases is enormous. In the center of a star, the pressure is great enough to heat the gases and cause nuclear fusion reactions. In a nu ...
Corona Australis
Corona Australis /kɵˈroʊnə ɒˈstreɪlɨs/ or Corona Austrina /kɵˈroʊnə ɒˈstraɪnə/ is a constellation in the Southern Celestial Hemisphere. Its Latin name means ""southern crown"", and it is the southern counterpart of Corona Borealis, the northern crown. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations. The Ancient Greeks saw Corona Australis as a wreath rather than a crown and associated it with Sagittarius or Centaurus. Other cultures have likened the pattern to a turtle, ostrich nest, a tent, or even a hut belonging to a rock hyrax.Although fainter than its namesake, the oval- or horseshoe-shaped pattern of its brighter stars renders it distinctive. Alpha and Beta Coronae Australis are the two brightest stars with an apparent magnitude of around 4.1. Epsilon Coronae Australis is the brightest example of a W Ursae Majoris variable in the southern sky. Lying alongside the Milky Way, Corona Australis contains one of the closest star-forming regions to our Solar System—a dusty dark nebula known as the Corona Australis Molecular Cloud, lying about 430 light years away. Within it are stars at the earliest stages of their lifespan. The variable stars R and TY Coronae Australis light up parts of the nebula, which varies in brightness accordingly.