Li-cai Deng
... The Future of Galactic structure In the Milky Way, we have the opportunity to learn the whole history of one galaxy instead of comparing snapshots of many. It is only now that we have large surveys of the whole sky that we are able to comprehend the Milky Way as a whole. Unlike external galaxies, t ...
... The Future of Galactic structure In the Milky Way, we have the opportunity to learn the whole history of one galaxy instead of comparing snapshots of many. It is only now that we have large surveys of the whole sky that we are able to comprehend the Milky Way as a whole. Unlike external galaxies, t ...
Project 4: The HR diagram. Open clusters
... tells you that there is some physical relationship between the luminosity and temperature of a star. From the figure, one sees that most stars fall along a diagonal strip from high temperature, high luminosity stars to low temperature, low luminosity stars. These are the main sequence ...
... tells you that there is some physical relationship between the luminosity and temperature of a star. From the figure, one sees that most stars fall along a diagonal strip from high temperature, high luminosity stars to low temperature, low luminosity stars. These are the main sequence ...
Birth - Wayne State University Physics and Astronomy
... undergo fusion into helium, with about 4 million tons turning to energy in the process This rate of hydrogen use means that eventually the Sun (and all other stars) will run out of central fuel ...
... undergo fusion into helium, with about 4 million tons turning to energy in the process This rate of hydrogen use means that eventually the Sun (and all other stars) will run out of central fuel ...
Carolina Kehrig
... Peculiar very hot stars in IZw18 1) very massive (300 M), metal-poor O stars ? Observations versus HeII-ionizing fluxes from radiation-driven wind models for the most massive, hottest O stars at the metallicity of IZw18 and below (Kudritzki 2002): the number of such stars needed to explain Q(HeII) ...
... Peculiar very hot stars in IZw18 1) very massive (300 M), metal-poor O stars ? Observations versus HeII-ionizing fluxes from radiation-driven wind models for the most massive, hottest O stars at the metallicity of IZw18 and below (Kudritzki 2002): the number of such stars needed to explain Q(HeII) ...
Document
... 3. The halo. Old stars (including the globular clusters) and very dilute interstellar matter form a roughly spherical Galactic halo around the disk. The inner part of the halo is at least as large across as the disk, perhaps 60,000 light-years in radius. The gas in the inner halo is hot, 100,000 K, ...
... 3. The halo. Old stars (including the globular clusters) and very dilute interstellar matter form a roughly spherical Galactic halo around the disk. The inner part of the halo is at least as large across as the disk, perhaps 60,000 light-years in radius. The gas in the inner halo is hot, 100,000 K, ...
Age Estimates of Globular Clusters in the Milky Way
... are thought to have coalesced early on from small-scale density fluctuations in the primordial gas cloud, which itself later coherently collapsed, dissipating its energy and settling into the disk of our Milky Way Galaxy. As a result, these objects populate a roughly spherical halo in our galaxy toda ...
... are thought to have coalesced early on from small-scale density fluctuations in the primordial gas cloud, which itself later coherently collapsed, dissipating its energy and settling into the disk of our Milky Way Galaxy. As a result, these objects populate a roughly spherical halo in our galaxy toda ...
STELLAR STRUCTURE AND EVOLUTION
... Spectrum . . . yields information about surface chemical composition and gravity Evidence from: • Individual stars • Binary systems • Star clusters....these reveal how stars evolve with time • Nuclear physics...energy source, synthesis of heavy elements No direct information about physical condition ...
... Spectrum . . . yields information about surface chemical composition and gravity Evidence from: • Individual stars • Binary systems • Star clusters....these reveal how stars evolve with time • Nuclear physics...energy source, synthesis of heavy elements No direct information about physical condition ...
Star Formation in Our Galaxy - Wiley-VCH
... dark clouds in Orion, determined by tracing the regions of strong obscuration in optical photographs. A number of the most prominent structures, such as L1630 and L1641, are labeled by their designations in the Lynds cloud catalogue. The shaded areas, including those with NGC numbers, are chiefly re ...
... dark clouds in Orion, determined by tracing the regions of strong obscuration in optical photographs. A number of the most prominent structures, such as L1630 and L1641, are labeled by their designations in the Lynds cloud catalogue. The shaded areas, including those with NGC numbers, are chiefly re ...
Spectroscopy Lecture 10
... A flare star brightens by a few tenths up to a magnitude in V (more in the UV) in a few seconds, returning to its normal luminosity within a few hours ...
... A flare star brightens by a few tenths up to a magnitude in V (more in the UV) in a few seconds, returning to its normal luminosity within a few hours ...
colour
... Spectrum . . . yields information about surface chemical composition and gravity Evidence from: • Individual stars • Binary systems • Star clusters....these reveal how stars evolve with time • Nuclear physics...energy source, synthesis of heavy elements No direct information about physical condition ...
... Spectrum . . . yields information about surface chemical composition and gravity Evidence from: • Individual stars • Binary systems • Star clusters....these reveal how stars evolve with time • Nuclear physics...energy source, synthesis of heavy elements No direct information about physical condition ...
11 - Visual Magnitudes Project
... Attached is a finding chart for the brighter stars in the open star cluster named Praesepe or M44 which lies in the constellation of Cancer, or Pleiades (M45) which lies in the constellation of Taurus. M44 and M45 are the 44th and 45th objects in the catalog compiled by Messier. Visual photometry is ...
... Attached is a finding chart for the brighter stars in the open star cluster named Praesepe or M44 which lies in the constellation of Cancer, or Pleiades (M45) which lies in the constellation of Taurus. M44 and M45 are the 44th and 45th objects in the catalog compiled by Messier. Visual photometry is ...
What units are used in astronomical photometry?
... Astrometry: Technological advances (including the Hubble Space Telescope) have improved parallax accuracy to 0.001” within a few years. Before 1990, fewer than 10,000 stellar parallaxes had been measured (and only 500 known well), but there are about 10 12 stars in our Galaxy. Space observations mad ...
... Astrometry: Technological advances (including the Hubble Space Telescope) have improved parallax accuracy to 0.001” within a few years. Before 1990, fewer than 10,000 stellar parallaxes had been measured (and only 500 known well), but there are about 10 12 stars in our Galaxy. Space observations mad ...
doc - Pocket Stars
... are performed for proper motions and parallax. Planet ephemeris data from Jet Propulsion Laboratory using the DE405 database. DE405 is JPL’s latest planetary ephemeris with correction for both nutations and librations. DE405 uses the J2000 International Celestial Reference Frame (ICRF). The portion ...
... are performed for proper motions and parallax. Planet ephemeris data from Jet Propulsion Laboratory using the DE405 database. DE405 is JPL’s latest planetary ephemeris with correction for both nutations and librations. DE405 uses the J2000 International Celestial Reference Frame (ICRF). The portion ...
Contents - Classroom Complete Press
... Each galaxy contains millions and millions of stars. The stars in each galaxy stay clumped together by gravity. Think of a galaxy like a big ship of stars floating around in the empty ocean of space. There isn’t just one ship in this ocean though. There are millions and millions of galaxies. You mig ...
... Each galaxy contains millions and millions of stars. The stars in each galaxy stay clumped together by gravity. Think of a galaxy like a big ship of stars floating around in the empty ocean of space. There isn’t just one ship in this ocean though. There are millions and millions of galaxies. You mig ...
SGHS Faulkes ASISTM Star Cluster Photometry
... The colour of a star is due to the temperature of its outer atmosphere. Relatively cool stars are orange or red and hot stars are white or blue. The temperature of a star’s outer layers is determined by how much energy a star is giving out and how far the star’s outer layers are from the centre of t ...
... The colour of a star is due to the temperature of its outer atmosphere. Relatively cool stars are orange or red and hot stars are white or blue. The temperature of a star’s outer layers is determined by how much energy a star is giving out and how far the star’s outer layers are from the centre of t ...
in search of antimatter in the universe
... ellipse. One such galaxy is Centaurus A, which is the closest galaxy to us with an AGN jet, at 3.7 Mega parsecs (1 parsec is 3.1x1016 m). This means its jet can be studied in greater detail than is possible in more remote sources. (Figure 5). This has allowed ‘knots’ in the jet to be resolved in x-r ...
... ellipse. One such galaxy is Centaurus A, which is the closest galaxy to us with an AGN jet, at 3.7 Mega parsecs (1 parsec is 3.1x1016 m). This means its jet can be studied in greater detail than is possible in more remote sources. (Figure 5). This has allowed ‘knots’ in the jet to be resolved in x-r ...
Cepheid Calibration
... after Edwin Hubble, who in 1929 discovered that the universe is expanding, the Hubble constant characterizes the present-day expansion rate of the universe and is required to determine its age. In practice, measurement of the Hubble constant is extraordinarily difficult—Edwin Hubble’s initial estima ...
... after Edwin Hubble, who in 1929 discovered that the universe is expanding, the Hubble constant characterizes the present-day expansion rate of the universe and is required to determine its age. In practice, measurement of the Hubble constant is extraordinarily difficult—Edwin Hubble’s initial estima ...
Copyright 1995 Scientific American, Inc.
... stars should not have existed. Astronomers believed that the repeated stellar catastrophes needed to create them would disrupt any gravitational binding between two stars. Neutron stars are the remnants of massive stars, which perish in a supernova explosion after exhausting all their nuclear fuel. ...
... stars should not have existed. Astronomers believed that the repeated stellar catastrophes needed to create them would disrupt any gravitational binding between two stars. Neutron stars are the remnants of massive stars, which perish in a supernova explosion after exhausting all their nuclear fuel. ...
relativistic time correction on movement of distant galaxies
... The latest information of the farthest galaxy is GN z11, having red shift 11. It is at apparent distance of 13.4 billion light years from Earth. That means, light that we have just received is giving information about 13.4 billion years old. This galaxy is reported to be containing stars. Suppose th ...
... The latest information of the farthest galaxy is GN z11, having red shift 11. It is at apparent distance of 13.4 billion light years from Earth. That means, light that we have just received is giving information about 13.4 billion years old. This galaxy is reported to be containing stars. Suppose th ...
1. What is parallax? What unit is it measured in? 1a. Parallax is the
... of how bright they appear in the sky starting with the least bright. 22a. D, C, E, F, A, B. 23. Stars A, B, C, D, E have absolute magnitudes -2, 0, 3, 5, 1 respectively. Put them in order of how bright they appear in the sky starting with the least bright. 23a. Cant do this since we dont know their ...
... of how bright they appear in the sky starting with the least bright. 22a. D, C, E, F, A, B. 23. Stars A, B, C, D, E have absolute magnitudes -2, 0, 3, 5, 1 respectively. Put them in order of how bright they appear in the sky starting with the least bright. 23a. Cant do this since we dont know their ...
14. The Milky Way Galaxy: A Spiral in Space
... – RR Lyrae stars all have about the same luminosity; knowing their apparent magnitude allows us to calculate the distance. – Cepheids have a luminosity that is strongly correlated with the period of their oscillations; once the period is measured, the luminosity is known and we can proceed as above. ...
... – RR Lyrae stars all have about the same luminosity; knowing their apparent magnitude allows us to calculate the distance. – Cepheids have a luminosity that is strongly correlated with the period of their oscillations; once the period is measured, the luminosity is known and we can proceed as above. ...
Paper - Astrophysics - University of Oxford
... properties then can be used to determine the albedos (reflectivities), and thereby the surface temperatures on detected planets. For large gas giants, rings like those around Saturn would reveal themselves as changes in the phase light curve of a planet (Fig. 1). On different timescales, the influen ...
... properties then can be used to determine the albedos (reflectivities), and thereby the surface temperatures on detected planets. For large gas giants, rings like those around Saturn would reveal themselves as changes in the phase light curve of a planet (Fig. 1). On different timescales, the influen ...
The Hydrogen 21-cm Emission Line
... The Trifid Nebula (right), named because of the dust lanes that trisect the H II region behind them, is next to the Lagoon Nebula in Sagittarius. The image to the right illustrates the three types of nebulae: the red H II region behind a dark dust nebula showing the effect of the extinction of light ...
... The Trifid Nebula (right), named because of the dust lanes that trisect the H II region behind them, is next to the Lagoon Nebula in Sagittarius. The image to the right illustrates the three types of nebulae: the red H II region behind a dark dust nebula showing the effect of the extinction of light ...
Serpens
Serpens (""the Serpent"", Greek Ὄφις) is a constellation of the northern hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations defined by the International Astronomical Union. It is unique among the modern constellations in being split into two non-contiguous parts, Serpens Caput (Serpent's Head) to the west and Serpens Cauda (Serpent's Tail) to the east. Between these two halves lies the constellation of Ophiuchus, the ""Serpent-Bearer"". In figurative representations, the body of the serpent is represented as passing behind Ophiuchus between Mu Serpentis in Serpens Caput and Nu Serpentis in Serpens Cauda.The brightest star in Serpens is the red giant star Alpha Serpentis, or Unukalhai, in Serpens Caput, with an apparent magnitude of 2.63. Also located in Serpens Caput are the naked-eye globular cluster Messier 5 and the naked-eye variables R Serpentis and Tau4 Serpentis. Notable extragalactic objects include Seyfert's Sextet, one of the densest galaxy clusters known; Arp 220, the prototypical ultraluminous infrared galaxy; and Hoag's Object, the most famous of the very rare class of galaxies known as ring galaxies.Part of the Milky Way's galactic plane passes through Serpens Cauda, which is therefore rich in galactic deep-sky objects, such as the Eagle Nebula (IC 4703) and its associated star cluster Messier 16. The nebula measures 70 light-years by 50 light-years and contains the Pillars of Creation, three dust clouds that became famous for the image taken by the Hubble Space Telescope. Other striking objects include the Red Square Nebula, one of the few objects in astronomy to take on a square shape; and Westerhout 40, a massive nearby star-forming region consisting of a molecular cloud and an H II region.