31-2 - Fremont Peak Observatory
... So if these are not planets and they are not “bright” then what are they? As bright nebulae herald the birth of stars, these herald the death of a star (at least a sun-sized) star. When a solar mass star approaches the end of its life it grows to a red giant in a last attempt to balance gravity and ...
... So if these are not planets and they are not “bright” then what are they? As bright nebulae herald the birth of stars, these herald the death of a star (at least a sun-sized) star. When a solar mass star approaches the end of its life it grows to a red giant in a last attempt to balance gravity and ...
The Milky Way Galaxy (ch. 23)
... HI and CO spectral lines for more distant regions. Result from radial velocities and distances: differential galactic rotation (23.12). Inner parts rotating faster than outer parts (at least at our distance from the center—see below). Note that this is just for the disk—the halo stars are moving dif ...
... HI and CO spectral lines for more distant regions. Result from radial velocities and distances: differential galactic rotation (23.12). Inner parts rotating faster than outer parts (at least at our distance from the center—see below). Note that this is just for the disk—the halo stars are moving dif ...
The evolution of spiral galaxies in clusters Kutdemir, Elif
... precise, it has to be implemented since the former is useless at large distances. Integrated spectra are composite, which means that they have contribution of different types of stars at a given wavelength and this mixture changes with wavelength. Here we will not talk about how this combination pro ...
... precise, it has to be implemented since the former is useless at large distances. Integrated spectra are composite, which means that they have contribution of different types of stars at a given wavelength and this mixture changes with wavelength. Here we will not talk about how this combination pro ...
PHYS3380_110415_bw - The University of Texas at Dallas
... Low luminosity; high temperature => White dwarfs are found in the lower left corner of the Hertzsprung-Russell diagram. ...
... Low luminosity; high temperature => White dwarfs are found in the lower left corner of the Hertzsprung-Russell diagram. ...
The HERMES GALAH survey: overview
... Figure 4: The Na-Ni distribution for globular cluster stars, dwarf spheroidal galaxy stars, field halo stars and stars of the Aquarius stream (black star symbols) (Wylie de Boer et al. 2012). The stars of the Aquarius stream are in the same part of the distribution as the globular cluster stars. ga ...
... Figure 4: The Na-Ni distribution for globular cluster stars, dwarf spheroidal galaxy stars, field halo stars and stars of the Aquarius stream (black star symbols) (Wylie de Boer et al. 2012). The stars of the Aquarius stream are in the same part of the distribution as the globular cluster stars. ga ...
US - Real Science
... Around one quarter of all large stars are born in starburst galaxies such as this. They spawn stars up to a thousand times faster than the Milky Way. In most starbursts the surge in starbirth is triggered when two galaxies come too close together. Mutual attraction between the galaxies causes immens ...
... Around one quarter of all large stars are born in starburst galaxies such as this. They spawn stars up to a thousand times faster than the Milky Way. In most starbursts the surge in starbirth is triggered when two galaxies come too close together. Mutual attraction between the galaxies causes immens ...
Astronomy in 1936 The History of the Universe
... • Molecular clouds form on inner edges of spiral arms. • HI gas flow shows discontinuity due to shocks at inner edges of spiral arms. • Bright young stars also in narrow arms. • Observed width ∆θ ~ t*(Ω - Ωp) , as predicted. ...
... • Molecular clouds form on inner edges of spiral arms. • HI gas flow shows discontinuity due to shocks at inner edges of spiral arms. • Bright young stars also in narrow arms. • Observed width ∆θ ~ t*(Ω - Ωp) , as predicted. ...
Astro 6590: Galaxies and the Universe Astro
... stars, plus an amount up to 1/2 of as much by mass of gas, and about 10X as much by mass of dark matter. The stars and gas are about 70% hydrogen by mass and 25% helium, the rest being heavier elements (called "metals"). • Typical scales are: masses between 106 to 1012 M (1 solar mass is 2 x 1030 k ...
... stars, plus an amount up to 1/2 of as much by mass of gas, and about 10X as much by mass of dark matter. The stars and gas are about 70% hydrogen by mass and 25% helium, the rest being heavier elements (called "metals"). • Typical scales are: masses between 106 to 1012 M (1 solar mass is 2 x 1030 k ...
A Collection of Curricula for the STARLAB Deep Sky Objects
... Nebulae are very important in astronomy because they are the key to understanding the birth of stars. All stars, including the sun, formed from nebulae like the Orion Nebula. Astronomers have also found, however, that certain types of nebulae mark the death of stars (see slides #62 and 63). In old a ...
... Nebulae are very important in astronomy because they are the key to understanding the birth of stars. All stars, including the sun, formed from nebulae like the Orion Nebula. Astronomers have also found, however, that certain types of nebulae mark the death of stars (see slides #62 and 63). In old a ...
MESSIER - EarthLink
... On September 7, he originally discovers his first deepsky object: The Saturn Nebula (NGC 7009). ...
... On September 7, he originally discovers his first deepsky object: The Saturn Nebula (NGC 7009). ...
CHAPTER 12—STELLAR EVOLUTION
... ____ 28. Stars swell into giants when hydrogen is exhausted in their centers. ____ 29. The helium flash is the cause of some supernovae. ____ 30. Helium fusion does not begin until the star has entered the giant region of the H-R diagram. ____ 31. Even in degenerate matter, pressure depends on tempe ...
... ____ 28. Stars swell into giants when hydrogen is exhausted in their centers. ____ 29. The helium flash is the cause of some supernovae. ____ 30. Helium fusion does not begin until the star has entered the giant region of the H-R diagram. ____ 31. Even in degenerate matter, pressure depends on tempe ...
Distance to the SMC
... Shapley in his calibration must be about 1.5 magnitudes fainter than the spiral arm Cepheids observed by Leavitt. That is, because Shapley based his scale on intrinsically fainter Population II stars, his scale needed to be adjusted to accommodate the intrinsically brighter Population I stars studie ...
... Shapley in his calibration must be about 1.5 magnitudes fainter than the spiral arm Cepheids observed by Leavitt. That is, because Shapley based his scale on intrinsically fainter Population II stars, his scale needed to be adjusted to accommodate the intrinsically brighter Population I stars studie ...
Clusters as laboratories for the study of galaxy evolution
... 3) More sensitive measurements of age and metallicity in stellar populations at 0.5 < z < 1.3 should decisive in distinguishing between these two possibilities in the near future. ...
... 3) More sensitive measurements of age and metallicity in stellar populations at 0.5 < z < 1.3 should decisive in distinguishing between these two possibilities in the near future. ...
Luminosity profiles and sizes of massive star clusters in NGC 7252
... We present Hubble Space Telescope (HST) Wide-Field Camera 3 (WFC3) images of the merger remnant NGC 7252. In particular, we focus on the surface brightness profiles and effective radii Reff of 36 young massive clusters (YMCs) within the galaxy. All the clusters have masses exceeding 105 M and are, ...
... We present Hubble Space Telescope (HST) Wide-Field Camera 3 (WFC3) images of the merger remnant NGC 7252. In particular, we focus on the surface brightness profiles and effective radii Reff of 36 young massive clusters (YMCs) within the galaxy. All the clusters have masses exceeding 105 M and are, ...
Lecture Notes – Galaxies
... Ellipticals contain old stars (Pop. II) and have very little interstellar material. Spirals contain young and old stars (Pop I and II) and have large amounts of interstellar material. It is thought that ellipticals formed most of their of stars early on, using up all their interstellar gas, and so d ...
... Ellipticals contain old stars (Pop. II) and have very little interstellar material. Spirals contain young and old stars (Pop I and II) and have large amounts of interstellar material. It is thought that ellipticals formed most of their of stars early on, using up all their interstellar gas, and so d ...
Chapter14(4-7-11)
... Stellar Populations • Turns out that there are two types of stars in the Galaxy – Population I: Relatively young. Similar to the Sun. Tend to be in the galactic disk. Richer in heavy elements – Population II: Few heavy elements, very old (12-14 billion years), tend to be in the center of the galax ...
... Stellar Populations • Turns out that there are two types of stars in the Galaxy – Population I: Relatively young. Similar to the Sun. Tend to be in the galactic disk. Richer in heavy elements – Population II: Few heavy elements, very old (12-14 billion years), tend to be in the center of the galax ...
Reassessing the formation of the inner Oort cloud
... to maximise dynamical interactions among the stars. However, the radii of embedded clusters presented in Lada & Lada (2003) might only be valid for the cores of the clusters that are listed. Recently Gutermuth et al. (2009) performed a Spitzer study of a large sample of embedded clusters, some of wh ...
... to maximise dynamical interactions among the stars. However, the radii of embedded clusters presented in Lada & Lada (2003) might only be valid for the cores of the clusters that are listed. Recently Gutermuth et al. (2009) performed a Spitzer study of a large sample of embedded clusters, some of wh ...
30-1 - Fremont Peak Observatory Association
... Way, but seeing the bulge requires an exceptionally dark sky. M 10, 12, and 14 are all an easy star hop from each other. There are also several bright NGC’s one of which is used as a mid-way point when hopping from 10-12 to 14. See them for real So come up to the peak this spring and summer and get ...
... Way, but seeing the bulge requires an exceptionally dark sky. M 10, 12, and 14 are all an easy star hop from each other. There are also several bright NGC’s one of which is used as a mid-way point when hopping from 10-12 to 14. See them for real So come up to the peak this spring and summer and get ...
Star Formation in the Local Milky Way
... attempt to determine the IMF was by Salpeter (1955) more than half a century ago. He derived the IMF from the luminosity function of local field stars (i.e., stars within ∼ 500 pc of the sun) by converting stellar luminosities to masses using empirical massluminosity relations. He corrected for loss ...
... attempt to determine the IMF was by Salpeter (1955) more than half a century ago. He derived the IMF from the luminosity function of local field stars (i.e., stars within ∼ 500 pc of the sun) by converting stellar luminosities to masses using empirical massluminosity relations. He corrected for loss ...
3D maps of the local interstellar medium: searching for the imprints
... towards 23,000 nearby stars is used to illustrate the potential of the more detailed maps that are expected within the next several years. The map reveals the location of the main IS cloud complexes up to distances on the order of 600 to 1200 pc depending on directions. Owing to target selection bia ...
... towards 23,000 nearby stars is used to illustrate the potential of the more detailed maps that are expected within the next several years. The map reveals the location of the main IS cloud complexes up to distances on the order of 600 to 1200 pc depending on directions. Owing to target selection bia ...
PHYS3380_110215_bw - The University of Texas at Dallas
... If the rising parcel cools to a lower temperature than its new surroundings, so that it has a higher density than the surrounding gas, then its lack of buoyancy will cause it to sink back to where it came from. However, if the temperature gradient is steep enough (i. e. the temperature changes rapid ...
... If the rising parcel cools to a lower temperature than its new surroundings, so that it has a higher density than the surrounding gas, then its lack of buoyancy will cause it to sink back to where it came from. However, if the temperature gradient is steep enough (i. e. the temperature changes rapid ...
Recipes for ULX formation: necessary ingredients and garnishments
... Myr (Portegies Zwart & McMillan 2002). However, we have argued that there is no longer a compelling need to invoke intermediate-mass BHs in ULXs, and that the upper mass limit is likely to be somewhere between 50 and 200M . Correspondingly, if dynamical collapse and merger processes are still neede ...
... Myr (Portegies Zwart & McMillan 2002). However, we have argued that there is no longer a compelling need to invoke intermediate-mass BHs in ULXs, and that the upper mass limit is likely to be somewhere between 50 and 200M . Correspondingly, if dynamical collapse and merger processes are still neede ...
Hubble`s Constant - Scientific Research Publishing
... Then, it is necessary to explore regions several tens or even hundreds of mega parsecs distant from the Earth, in order to be sure that we are looking at the expanding Universe and not just some local motion. Nevertheless, at such great distances it is impossible to distinguish individual stars insi ...
... Then, it is necessary to explore regions several tens or even hundreds of mega parsecs distant from the Earth, in order to be sure that we are looking at the expanding Universe and not just some local motion. Nevertheless, at such great distances it is impossible to distinguish individual stars insi ...
GG_CERN_0707
... • Dark halos are `predicted’ down to sub-earth masses; but… • Neither the local disk, nor star clusters, nor spiral arms, nor GMC, nor the solar system, have associated DM: Given the absence of a very local enhancement, what is the smallest scale on which DM is concentrated? How can sub-halos in dSp ...
... • Dark halos are `predicted’ down to sub-earth masses; but… • Neither the local disk, nor star clusters, nor spiral arms, nor GMC, nor the solar system, have associated DM: Given the absence of a very local enhancement, what is the smallest scale on which DM is concentrated? How can sub-halos in dSp ...
Open cluster
An open cluster, also known as galactic cluster, is a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way Galaxy, and many more are thought to exist. They are loosely bound by mutual gravitational attraction and become disrupted by close encounters with other clusters and clouds of gas as they orbit the galactic center, resulting in a migration to the main body of the galaxy as well as a loss of cluster members through internal close encounters. Open clusters generally survive for a few hundred million years, with the most massive ones surviving for a few billion years. In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for longer. Open clusters have been found only in spiral and irregular galaxies, in which active star formation is occurring.Young open clusters may still be contained within the molecular cloud from which they formed, illuminating it to create an H II region. Over time, radiation pressure from the cluster will disperse the molecular cloud. Typically, about 10% of the mass of a gas cloud will coalesce into stars before radiation pressure drives the rest of the gas away.Open clusters are key objects in the study of stellar evolution. Because the cluster members are of similar age and chemical composition, their properties (such as distance, age, metallicity and extinction) are more easily determined than they are for isolated stars. A number of open clusters, such as the Pleiades, Hyades or the Alpha Persei Cluster are visible with the naked eye. Some others, such as the Double Cluster, are barely perceptible without instruments, while many more can be seen using binoculars or telescopes. The Wild Duck Cluster, M11, is an example.