Annual report 2004 - Département d`Astrophysique, Géophysique et
... the Scuti star XX Pyx. Applying a cross-correlation technique to the spectra, we found clear radialvelocity variations with a large amplitude. We derive the orbital parameters and confirm an orbital period of 1.15d, as suggested previously on the basis of photometric variations. The amplitude of the ...
... the Scuti star XX Pyx. Applying a cross-correlation technique to the spectra, we found clear radialvelocity variations with a large amplitude. We derive the orbital parameters and confirm an orbital period of 1.15d, as suggested previously on the basis of photometric variations. The amplitude of the ...
Supermassive Black Holes and the Growth of Galaxies
... The equations of gravity tell us that the escape velocity for a spherical object (such as a star or planet) is given by vesc = GM/R. Thus, if we make an object more massive (larger M) or compress it (smaller R), then we increase the escape velocity. Taking this to its extreme, we can imagine taking ...
... The equations of gravity tell us that the escape velocity for a spherical object (such as a star or planet) is given by vesc = GM/R. Thus, if we make an object more massive (larger M) or compress it (smaller R), then we increase the escape velocity. Taking this to its extreme, we can imagine taking ...
Late Summer Messier Objects
... In addition, they are well-placed only during the summer, when the nights are at their shortest and the logistics of observing are most problematic. But they are not quite as bad in this regard as the objects between RA 15 and RA 18, at least not for people who do most of their observing in the even ...
... In addition, they are well-placed only during the summer, when the nights are at their shortest and the logistics of observing are most problematic. But they are not quite as bad in this regard as the objects between RA 15 and RA 18, at least not for people who do most of their observing in the even ...
s-process
... The heavy n-capture elements were formed predominantly by the r-process at metallicities below [Fe/H] = -2.1. Elements from the s-process appear at a metallicity of [Fe/H] = -2.1, when low-mass AGB stars begin to contribute from double shell burning. The s-process then dominates Ba production. The o ...
... The heavy n-capture elements were formed predominantly by the r-process at metallicities below [Fe/H] = -2.1. Elements from the s-process appear at a metallicity of [Fe/H] = -2.1, when low-mass AGB stars begin to contribute from double shell burning. The s-process then dominates Ba production. The o ...
Dancing with Stars 3 Dancing with Stars Binary Stellar Evolution 1
... to the Sun is Alpha Centauri. Less well known is that Alpha Centauri has a companion in wide orbit, known as Proxima Centauri. A closer examination shows that Alpha Centauri itself is not a single star but has a closely orbiting companion as well. Of the “two” stars closest to the Sun, three are in ...
... to the Sun is Alpha Centauri. Less well known is that Alpha Centauri has a companion in wide orbit, known as Proxima Centauri. A closer examination shows that Alpha Centauri itself is not a single star but has a closely orbiting companion as well. Of the “two” stars closest to the Sun, three are in ...
Chapter 12
... Mass of a Star-Forming Cloud • A typical molecular cloud (T~ 30 K, n ~ 300 particles/cm3) must contain at least a few hundred solar masses for gravity to overcome pressure. • The cloud can prevent a pressure buildup by converting thermal energy into infrared and radio photons that escape the cloud. ...
... Mass of a Star-Forming Cloud • A typical molecular cloud (T~ 30 K, n ~ 300 particles/cm3) must contain at least a few hundred solar masses for gravity to overcome pressure. • The cloud can prevent a pressure buildup by converting thermal energy into infrared and radio photons that escape the cloud. ...
Next Generation Sunshine State Standards Chapter 24
... The oldest means of classifying stars is based on their brightness, also called luminosity or magnitude. It is natural to assume that very bright stars are somehow different from very dim stars. Three factors control the brightness of a star as seen from Earth: how big it is, how hot it is, and how ...
... The oldest means of classifying stars is based on their brightness, also called luminosity or magnitude. It is natural to assume that very bright stars are somehow different from very dim stars. Three factors control the brightness of a star as seen from Earth: how big it is, how hot it is, and how ...
Full Poster - Cool Cosmos
... Visible-light images show us the detailed structure of various types of galaxies, while radio images show quite a different picture of huge jets and lobes of material ejected from galactic cores. X-rays are used to detect the signature of black holes in the centers of galaxies – the extremely hot ma ...
... Visible-light images show us the detailed structure of various types of galaxies, while radio images show quite a different picture of huge jets and lobes of material ejected from galactic cores. X-rays are used to detect the signature of black holes in the centers of galaxies – the extremely hot ma ...
A Hero`s Little Horse: Discovery of a Dissolving Star Cluster in
... the underlying stellar distribution. We obtain a half-light radius of 1.2 ± 0.1 arcmin or rh = 6.9 ± 0.6 pc, adopting the distance modulus of 16.48 mag. In analogy to Walsh et al. (2008) we estimate the total luminosity of Kim 1 by integrating the radial number density profile shown in Figure 6 to c ...
... the underlying stellar distribution. We obtain a half-light radius of 1.2 ± 0.1 arcmin or rh = 6.9 ± 0.6 pc, adopting the distance modulus of 16.48 mag. In analogy to Walsh et al. (2008) we estimate the total luminosity of Kim 1 by integrating the radial number density profile shown in Figure 6 to c ...
The old globular cluster system of the dIrr galaxy NGC 1427A in the
... (2000) and Harris (2003). In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxie ...
... (2000) and Harris (2003). In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxie ...
Chapter 17 Star Stuff
... • He fuses into carbon in a shell around the carbon core, and H fuses to He in a shell around the helium ...
... • He fuses into carbon in a shell around the carbon core, and H fuses to He in a shell around the helium ...
Life Cycle of a Star Lesson Plan
... but not neon, in which case an oxygen-neon-magnesium white dwarf may be formed.[7] Also, some helium white dwarfs[8][9] appear to have been formed by mass loss in binary systems. The material in a white dwarf no longer undergoes fusion reactions, so the star has no source of energy, nor is it suppo ...
... but not neon, in which case an oxygen-neon-magnesium white dwarf may be formed.[7] Also, some helium white dwarfs[8][9] appear to have been formed by mass loss in binary systems. The material in a white dwarf no longer undergoes fusion reactions, so the star has no source of energy, nor is it suppo ...
death_high_mass
... Low mass stars cannot fuse Carbon • Core temperature is too low to fuse Carbon into other elements. • The core shrinks until all the free electrons are trapped in spaces between the Carbon nuclei. They set up energy levels and the core acts like a giant atom. Core cannot shrink any more. • The core ...
... Low mass stars cannot fuse Carbon • Core temperature is too low to fuse Carbon into other elements. • The core shrinks until all the free electrons are trapped in spaces between the Carbon nuclei. They set up energy levels and the core acts like a giant atom. Core cannot shrink any more. • The core ...
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 ...
Photometry – I. “All sky”
... years, you might not even be able to get the same glass that was used previously. Detectors are also not really uniform; CCDs are much more red-sensitive than photomultipliers and different types (of either) might have significantly different responses as a function of wavelength. At the same time, ...
... years, you might not even be able to get the same glass that was used previously. Detectors are also not really uniform; CCDs are much more red-sensitive than photomultipliers and different types (of either) might have significantly different responses as a function of wavelength. At the same time, ...
Cosmology with GMRT
... – Apply to a single object (optical results are averages over large redshift range) – Not subject to the same systematics – Currently probe a complementary redshift range ...
... – Apply to a single object (optical results are averages over large redshift range) – Not subject to the same systematics – Currently probe a complementary redshift range ...
Gamma Ray Bursts - University of Arizona
... foretelling on the basis of observation, experience or scientific reasoning. • Postdiction – (from Latin: post- after + dicere to say): To explain an observation after the fact. • If your model “predicts” all possible outcomes, it is not a prediction. This merely states that you can not constrain th ...
... foretelling on the basis of observation, experience or scientific reasoning. • Postdiction – (from Latin: post- after + dicere to say): To explain an observation after the fact. • If your model “predicts” all possible outcomes, it is not a prediction. This merely states that you can not constrain th ...
01-Star Atlas Project - Mapping the Heavens
... of caution: up and down on the maps correspond to north and south on the celestial sphere only because people always hold maps with the north side up. In the sky, they are definitely not synonymous (as you'll learn in Chapter 2). Right ascension on the equatorial maps increases to the left, so left ...
... of caution: up and down on the maps correspond to north and south on the celestial sphere only because people always hold maps with the north side up. In the sky, they are definitely not synonymous (as you'll learn in Chapter 2). Right ascension on the equatorial maps increases to the left, so left ...
ISP205L, Week 13 Computer Lab Activity The Distance to the Pleiades
... where m = the apparent magnitude, M = the absolute magnitude, and d = the distance in parsecs. At long last, equation (8) is the one that we need for this lab exercise. 4. Back to the Pleiades For the lab exercise we are going to give you an H-R diagram that plots the absolute magnitudes (M) of stan ...
... where m = the apparent magnitude, M = the absolute magnitude, and d = the distance in parsecs. At long last, equation (8) is the one that we need for this lab exercise. 4. Back to the Pleiades For the lab exercise we are going to give you an H-R diagram that plots the absolute magnitudes (M) of stan ...
The Formation and Evolution of the Milky Way
... blobs of gas. How the universe made the Milky Way from such simple beginnings is not altogether clear. The task of unraveling this mystery has been cast to astronomers, such as myself, who attempt to construct models of the Galaxy’s evolution based on its present appearance. These models need to acc ...
... blobs of gas. How the universe made the Milky Way from such simple beginnings is not altogether clear. The task of unraveling this mystery has been cast to astronomers, such as myself, who attempt to construct models of the Galaxy’s evolution based on its present appearance. These models need to acc ...
10 - Keele Astrophysics Group
... spectrum and realised that there was a clear pattern of absorption lines superimposed on the continuum. By the end of that century, astronomers were able to examine the spectra of stars in large numbers and realised that stars could be divided into groups according to the general appearance of their ...
... spectrum and realised that there was a clear pattern of absorption lines superimposed on the continuum. By the end of that century, astronomers were able to examine the spectra of stars in large numbers and realised that stars could be divided into groups according to the general appearance of their ...
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... (From http://www.angelfire.com/sc2/Trunko/starsh1.JPG) ...
... (From http://www.angelfire.com/sc2/Trunko/starsh1.JPG) ...
13.1 Introduction 13.2 The Red Giant Branch
... Grains are microscopic solid particles that can condense out of the gas phase at the values of temperature and pressure typical of the extended atmospheres of late-type giant and supergiant stars. Their presence in these environments is indicated by a number of infrared spectral features, such as th ...
... Grains are microscopic solid particles that can condense out of the gas phase at the values of temperature and pressure typical of the extended atmospheres of late-type giant and supergiant stars. Their presence in these environments is indicated by a number of infrared spectral features, such as th ...
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.