Magnitudes lesson plan
... that he could see from his latitude into six classes of brightness. His idea of six classes probably came from the Babylonians whose base number was six. The formal introduction of six magnitudes has been credited to Ptolemy (100-150 A.D.) who was a Greek/Egyptian astronomer. He simply advanced the ...
... that he could see from his latitude into six classes of brightness. His idea of six classes probably came from the Babylonians whose base number was six. The formal introduction of six magnitudes has been credited to Ptolemy (100-150 A.D.) who was a Greek/Egyptian astronomer. He simply advanced the ...
Document
... the most common. And here we come to a most interesting relationship that seems to apply universally, regardless of what sorts of phenomena are being studied. This is the inverse relationship that exists between size and abundance. Astrophysicists have found this relationship to hold, for example, b ...
... the most common. And here we come to a most interesting relationship that seems to apply universally, regardless of what sorts of phenomena are being studied. This is the inverse relationship that exists between size and abundance. Astrophysicists have found this relationship to hold, for example, b ...
Slide 1
... White dwarfs have a population of cold, large radii, low mass, hard to detect Kuiper belt like discs. Observations find hot, dusty discs within tidal radius Can we link the two populations? Maybe the Kuiper-belts provide the reservoir of material required to replenish the hot discs? We just need a m ...
... White dwarfs have a population of cold, large radii, low mass, hard to detect Kuiper belt like discs. Observations find hot, dusty discs within tidal radius Can we link the two populations? Maybe the Kuiper-belts provide the reservoir of material required to replenish the hot discs? We just need a m ...
The HIRES science case
... solve some of the issues, others remain puzzling and may hint to more fundamental problems in our understanding. For example, the migration timescale appears to be quite short, so why have not all the planets "fallen" into their star? Why is it that Jupiter appears not to have migrated significantl ...
... solve some of the issues, others remain puzzling and may hint to more fundamental problems in our understanding. For example, the migration timescale appears to be quite short, so why have not all the planets "fallen" into their star? Why is it that Jupiter appears not to have migrated significantl ...
Chapter 13 – Behavior of Spectral Lines
... • How strong is a Ba II line (at 0 eV) in a 6000K star compared to a 5000K star? • How do the strengths of a 5 eV Fe II line compare in the same two stars? • For Ba II, EQW decreases by 25% • For Fe II, EQW is almost x3 larger ...
... • How strong is a Ba II line (at 0 eV) in a 6000K star compared to a 5000K star? • How do the strengths of a 5 eV Fe II line compare in the same two stars? • For Ba II, EQW decreases by 25% • For Fe II, EQW is almost x3 larger ...
Properties of Galactic early-type O
... all stars show many narrow lines of interstellar origin. This interstellar contamination dominates the whole UV spectrum of HD 15570; only strong lines such as C iv λλ1548-1550 or N iv λ1718 can be used safely for this star. All stars but HD 66811 were observed with FUSE through the LWRS 30 × 30 ...
... all stars show many narrow lines of interstellar origin. This interstellar contamination dominates the whole UV spectrum of HD 15570; only strong lines such as C iv λλ1548-1550 or N iv λ1718 can be used safely for this star. All stars but HD 66811 were observed with FUSE through the LWRS 30 × 30 ...
Astronomy 112: The Physics of Stars Class 14 Notes: The Main
... stars spend most of their lives: the main sequence. Our goal is to demonstrate that we can understand the main sequence qualitatively in terms of our simple stellar evolution model, and then to examine some detailed numerical results. I. Homology and Scalings on the Main Sequence A. The Non-Dimensio ...
... stars spend most of their lives: the main sequence. Our goal is to demonstrate that we can understand the main sequence qualitatively in terms of our simple stellar evolution model, and then to examine some detailed numerical results. I. Homology and Scalings on the Main Sequence A. The Non-Dimensio ...
ppt - SLAC
... 1. Black-body temperature sets the star's color and determines its surface brightness: 2. Atmospheric pressure depends on the star's surface gravity and so, roughly, on its size —a giant, dwarf, or in between. The size and surface brightness yield the star's luminosity and often its evolutionary sta ...
... 1. Black-body temperature sets the star's color and determines its surface brightness: 2. Atmospheric pressure depends on the star's surface gravity and so, roughly, on its size —a giant, dwarf, or in between. The size and surface brightness yield the star's luminosity and often its evolutionary sta ...
sections 12-15 instructor notes
... the University of Toronto, April 1979) Luminosity Functions. Every astronomer deals almost daily with luminosity functions of some sort. In a way the most basic of such functions is the general luminosity function (GLF), which gives us the distribution function of absolute magnitude, M, for the aver ...
... the University of Toronto, April 1979) Luminosity Functions. Every astronomer deals almost daily with luminosity functions of some sort. In a way the most basic of such functions is the general luminosity function (GLF), which gives us the distribution function of absolute magnitude, M, for the aver ...
Rotation Periods and Relative Ages of Solar-Type Stars
... on axes of log Teff (effective temperature) and δMbol (bolometric luminosity). Also, Ca II H (396.8 nm) and K (383.4 nm) chromospheric emissions are empirically linked to ages (Soderblom et al. 1991). By fitting Strömgren uvby-Hβ photometry data to theoretical isochrones, isochrone ages may be compa ...
... on axes of log Teff (effective temperature) and δMbol (bolometric luminosity). Also, Ca II H (396.8 nm) and K (383.4 nm) chromospheric emissions are empirically linked to ages (Soderblom et al. 1991). By fitting Strömgren uvby-Hβ photometry data to theoretical isochrones, isochrone ages may be compa ...
Astronomy 112: The Physics of Stars Class 16 Notes: Post
... thermal energy U ∝ M T . Since the mass is fixed, the only way for Ω to increase is if R gets larger (since this brings Ω closer to zero), and the only way for U to decrease is for the mean temperature T to decrease. Thus the unstable increase in nuclear burning causes the radius of the star to exp ...
... thermal energy U ∝ M T . Since the mass is fixed, the only way for Ω to increase is if R gets larger (since this brings Ω closer to zero), and the only way for U to decrease is for the mean temperature T to decrease. Thus the unstable increase in nuclear burning causes the radius of the star to exp ...
Neon and oxygen in low activity stars: towards a coronal unification
... Aims. The disagreement between helioseismology and a recent downward revision of solar abundances has resulted in a controversy about the true neon abundance of the Sun and other stars. We study the coronal Ne/O abundance ratios of nearby stars with modest activity levels and investigate a possible ...
... Aims. The disagreement between helioseismology and a recent downward revision of solar abundances has resulted in a controversy about the true neon abundance of the Sun and other stars. We study the coronal Ne/O abundance ratios of nearby stars with modest activity levels and investigate a possible ...
Proto-planetary disks
... • direct measure of disk size (100-800 AU, bigger than dust) and inclination • demonstrates keplerian disk rotation (dynamical masses for stars) and direction of motion • AB Aur non-keplerian so not in equilibrium? (Pietu et al. 2005) • RW Aur has 48AU disk around A, asymmetric disk B, as well a ...
... • direct measure of disk size (100-800 AU, bigger than dust) and inclination • demonstrates keplerian disk rotation (dynamical masses for stars) and direction of motion • AB Aur non-keplerian so not in equilibrium? (Pietu et al. 2005) • RW Aur has 48AU disk around A, asymmetric disk B, as well a ...
Dr. Amanda Karakas and Prof. John Lattanzio
... supernova (> 10 solar masses); 2. Stars that evolve through the first and asymptotic giant branches (< 10 solar masses) ...
... supernova (> 10 solar masses); 2. Stars that evolve through the first and asymptotic giant branches (< 10 solar masses) ...
Satellities - stoweschools.com
... Bipolar Star System Two stars 8x1010m apart rotate about a point 4x1010 m from each other in a circular path in 12.6 years. The two stars have the same mass. What is the mass of the stars? Fg causes the centripetal acceleration therefore Fg = Fc ...
... Bipolar Star System Two stars 8x1010m apart rotate about a point 4x1010 m from each other in a circular path in 12.6 years. The two stars have the same mass. What is the mass of the stars? Fg causes the centripetal acceleration therefore Fg = Fc ...
observations of white dwarfs in the solar neighborhood
... currently being gathered. High proper motion surveys are particularly interesting in helping complete the local census of white dwarfs and in identifying possible white dwarf halo candidates. Salim & Gould (2002) have used a VJ reduced proper-motion (RPM) diagram (V + 5 log vs. VJ ) to identify ...
... currently being gathered. High proper motion surveys are particularly interesting in helping complete the local census of white dwarfs and in identifying possible white dwarf halo candidates. Salim & Gould (2002) have used a VJ reduced proper-motion (RPM) diagram (V + 5 log vs. VJ ) to identify ...
Astronomy Astrophysics NGC 7419 as a template for red supergiant clusters &
... tracks. Though the presence of five red supergiants is marginally consistent with theoretical expectations, the high number of Be stars and very low number of luminous evolved B stars hint at some unknown physical factor that is not considered in current synthesis models. Key words. open clusters an ...
... tracks. Though the presence of five red supergiants is marginally consistent with theoretical expectations, the high number of Be stars and very low number of luminous evolved B stars hint at some unknown physical factor that is not considered in current synthesis models. Key words. open clusters an ...
Isotopic composition of Hg and Pt in 5 slowly rotating HgMn stars *
... stars often relied on spectra of rather low resolution and low S/N ratio, so that only limited information could be derived from the centroid wavelength of unresolved isotopic blends. In this paper we present the results of a study of the isotopic compositions of Hg and Pt in 5 very slowly rotating ...
... stars often relied on spectra of rather low resolution and low S/N ratio, so that only limited information could be derived from the centroid wavelength of unresolved isotopic blends. In this paper we present the results of a study of the isotopic compositions of Hg and Pt in 5 very slowly rotating ...
The Chemical Composition of Carbon-Rich, Very Metal
... put forward to account for the moderately metal-poor classical CH stars ([Fe/H]∼ −1.5). These are usually explained by a model involving mass transfer from a carbon-enhanced asymptotic giant branch (AGB) star (one that has since evolved to the white dwarf stage and cannot now be seen) to its lower-m ...
... put forward to account for the moderately metal-poor classical CH stars ([Fe/H]∼ −1.5). These are usually explained by a model involving mass transfer from a carbon-enhanced asymptotic giant branch (AGB) star (one that has since evolved to the white dwarf stage and cannot now be seen) to its lower-m ...
Introduction: The History and Technique of Stellar Classification
... Introduction: The History and Technique of Stellar Classification Patterns of absorption lines were first observed in the spectrum of the sun by the German physicist Joseph von Fraunhofer early in the 1800’s, but it was not until late in that century that astronomers were able to routinely examine t ...
... Introduction: The History and Technique of Stellar Classification Patterns of absorption lines were first observed in the spectrum of the sun by the German physicist Joseph von Fraunhofer early in the 1800’s, but it was not until late in that century that astronomers were able to routinely examine t ...
star
... main sequence. In all main-sequence stars, nuclear fusion converts hydrogen into helium at a stable rate. There is an equilibrium between the outward thermal pressure from fusion and gravity’s inward pull. The amount of gas and dust available when a star forms determines the mass of each young star. ...
... main sequence. In all main-sequence stars, nuclear fusion converts hydrogen into helium at a stable rate. There is an equilibrium between the outward thermal pressure from fusion and gravity’s inward pull. The amount of gas and dust available when a star forms determines the mass of each young star. ...
Export To Word
... We need you to help classify this short list of 5 new stars using a Hertzsprung-Russell Diagram. The Sun has also been provided as a 6th star in this group for comparison. Please add these 5 new stars to your previously completed H-R Diagram. You will once again be classifying these stars based on t ...
... We need you to help classify this short list of 5 new stars using a Hertzsprung-Russell Diagram. The Sun has also been provided as a 6th star in this group for comparison. Please add these 5 new stars to your previously completed H-R Diagram. You will once again be classifying these stars based on t ...
GAIA A Stereoscopic Census of our Galaxy
... its formation and chemical history (accretion/interaction events) a rigorous framework for stellar structure and evolution theories a large-scale survey of extra-solar planets (up to ~20,000) a large-scale survey of Solar System bodies (~100,000) rare stellar types and rapid evolutionary phases in ...
... its formation and chemical history (accretion/interaction events) a rigorous framework for stellar structure and evolution theories a large-scale survey of extra-solar planets (up to ~20,000) a large-scale survey of Solar System bodies (~100,000) rare stellar types and rapid evolutionary phases in ...
High precision effective temperatures for 181 F-
... for giants with an error of only 33 K. So far however the line-ratio method has not been fully utilized for the purposes other than just temperature estimation by itself. One of few applications is the chemical abundance analysis of supergiants, where it has proved the anticipated high efficiency an ...
... for giants with an error of only 33 K. So far however the line-ratio method has not been fully utilized for the purposes other than just temperature estimation by itself. One of few applications is the chemical abundance analysis of supergiants, where it has proved the anticipated high efficiency an ...
Habitability of super-Earth planets around main
... 4.58 Gyr, see Schröder & Smith (2008) (for a metallicity of Z = 0.018), and the Sun’s present-day effective temperature is identified as Teff = 5774 K. Masses below 0.5 M⊙, i.e. mostly M-type stars, have been omitted from our study. Their stellar evolution can be neglected; their luminosity and stell ...
... 4.58 Gyr, see Schröder & Smith (2008) (for a metallicity of Z = 0.018), and the Sun’s present-day effective temperature is identified as Teff = 5774 K. Masses below 0.5 M⊙, i.e. mostly M-type stars, have been omitted from our study. Their stellar evolution can be neglected; their luminosity and stell ...
Stellar classification
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Light from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with absorption lines. Each line indicates an ion of a certain chemical element, with the line strength indicating the abundance of that ion. The relative abundance of the different ions varies with the temperature of the photosphere. The spectral class of a star is a short code summarizing the ionization state, giving an objective measure of the photosphere's temperature and density.Most stars are currently classified under the Morgan–Keenan (MK) system using the letters O, B, A, F, G, K, and M, a sequence from the hottest (O type) to the coolest (M type). Each letter class is then subdivided using a numeric digit with 0 being hottest and 9 being coolest (e.g. A8, A9, F0, F1 form a sequence from hotter to cooler). The sequence has been expanded with classes for other stars and star-like objects that do not fit in the classical system, such class D for white dwarfs and class C for carbon stars.In the MK system a luminosity class is added to the spectral class using Roman numerals. This is based on the width of certain absorption lines in the star's spectrum which vary with the density of the atmosphere and so distinguish giant stars from dwarfs. Luminosity class 0 or Ia+ stars for hypergiants, class I stars for supergiants, class II for bright giants, class III for regular giants, class IV for sub-giants, class V for main-sequence stars, class sd for sub-dwarfs, and class D for white dwarfs. The full spectral class for the Sun is then G2V, indicating a main-sequence star with a temperature around 5,800K.