Notes
... When most of the atoms of an element are in the same or a lower state of ionization, lines are sensitive to pressure – For lines from species in the dominant ionization state, the continuous opacity (if H-) depends on electron pressure but the line opacity is independent of electron pressure Lines f ...
... When most of the atoms of an element are in the same or a lower state of ionization, lines are sensitive to pressure – For lines from species in the dominant ionization state, the continuous opacity (if H-) depends on electron pressure but the line opacity is independent of electron pressure Lines f ...
The DB gap and a new class of pulsating white dwarfs
... completely absent. Small amount of contamination would not be ruled out even if hydrogen lines are not detectable. How much hydrogen can be still retained in the envelope of DO or DB white dwarfs is quite uncertain, but presumably the upper limit is less than 10−14 M . If hydrogen more than 10−14 M ...
... completely absent. Small amount of contamination would not be ruled out even if hydrogen lines are not detectable. How much hydrogen can be still retained in the envelope of DO or DB white dwarfs is quite uncertain, but presumably the upper limit is less than 10−14 M . If hydrogen more than 10−14 M ...
Lecture 15
... begins to gravitationally collapse • Material from the molecular cloud falls on it, adding energy to its collapse • This raises the temperature ASTR111 Lecture 15 ...
... begins to gravitationally collapse • Material from the molecular cloud falls on it, adding energy to its collapse • This raises the temperature ASTR111 Lecture 15 ...
Here
... • The pieces so far: Energy generation (nuclear fusion). Ideal gas law (relation between temperature, pressure, and volume. Hydrostatic equilibrium (gravity balances pressure). Continuity of mass (smooth distribution throughout the star). Continuity of energy (amount entering the bottom of ...
... • The pieces so far: Energy generation (nuclear fusion). Ideal gas law (relation between temperature, pressure, and volume. Hydrostatic equilibrium (gravity balances pressure). Continuity of mass (smooth distribution throughout the star). Continuity of energy (amount entering the bottom of ...
17_LectureOutline
... More Precisely 17-3: Measuring Stellar Masses in Binary Stars In order to measure stellar masses in a binary star, the period and semimajor axis of the orbit must be measured. Once this is done, Kepler’s third law gives the sum of the masses of the two stars. Then the relative speeds of the two sta ...
... More Precisely 17-3: Measuring Stellar Masses in Binary Stars In order to measure stellar masses in a binary star, the period and semimajor axis of the orbit must be measured. Once this is done, Kepler’s third law gives the sum of the masses of the two stars. Then the relative speeds of the two sta ...
ASTRONOMY AND ASTROPHYSICS How many low
... to be straightforward, dominated by the net production of this light element by low mass stars (i.e., with masses lower than 2 M! ). In these objects, initial D is processed to 3 He during the pre-main sequence phase. Then, as described by Iben (1967), an ...
... to be straightforward, dominated by the net production of this light element by low mass stars (i.e., with masses lower than 2 M! ). In these objects, initial D is processed to 3 He during the pre-main sequence phase. Then, as described by Iben (1967), an ...
March 2011
... area of sky about the same size as the full Moon. Using a pair of 10 x 50 binoculars another thirty or so fainter stars can be seen embedded within the Seven Sisters. A telescope will enable many more to be counted up to around 300 in total. Most telescopes will however have a field of view too smal ...
... area of sky about the same size as the full Moon. Using a pair of 10 x 50 binoculars another thirty or so fainter stars can be seen embedded within the Seven Sisters. A telescope will enable many more to be counted up to around 300 in total. Most telescopes will however have a field of view too smal ...
Continuous Spectrum—Kirchoff`s First Law
... This plot shows us that the main sequence is a mass sequence. The more massive a main sequence star is, the brighter and hotter it is. To understand this, we will consider the physics that goes on inside of stars. For the moment, we will just take it as a fact that we have determined observationally ...
... This plot shows us that the main sequence is a mass sequence. The more massive a main sequence star is, the brighter and hotter it is. To understand this, we will consider the physics that goes on inside of stars. For the moment, we will just take it as a fact that we have determined observationally ...
4. Star Formation
... It is now well established that stars form from gas and dust in the ISM. Young stars and massive stars are preferably found close to/within molecular clouds. This obscuration hence requires observations at infrared, millimetre, or radio wavelength. The problems of star formation: Create a star (radi ...
... It is now well established that stars form from gas and dust in the ISM. Young stars and massive stars are preferably found close to/within molecular clouds. This obscuration hence requires observations at infrared, millimetre, or radio wavelength. The problems of star formation: Create a star (radi ...
A) Polaris B) Betelgeuse C) Procyon B D) Sirius 1. Which star has a
... D) red dwarf star 60. Two stars of the same color are plotted on an H-R diagram. Star A is more luminous than star B. Which one of the following statements could explain this? A) Star A is hotter than star B. B) Star A is more distant than star B. C) Star A appears brighter in the sky than star B. D ...
... D) red dwarf star 60. Two stars of the same color are plotted on an H-R diagram. Star A is more luminous than star B. Which one of the following statements could explain this? A) Star A is hotter than star B. B) Star A is more distant than star B. C) Star A appears brighter in the sky than star B. D ...
Problem Set 2 for Astro 322 Read chapter 24.2. (Some of this
... Comparing this with the expression for LD above, we see they differ by only 2πh2R , and thus that LD = 2πh2R I(R = 0). For the Milky Way, 1.5 × 1010 L = 2πh2R I(R = 0), and I(R) = I(R = 0) exp[−R/hR ]. We find I(R = 0) = LD /(2πh2R ) = 1.5 × 1010 L /(2π(4000pc)2 ) = 149 L pc−2 . Then I(R = 8kpc) ...
... Comparing this with the expression for LD above, we see they differ by only 2πh2R , and thus that LD = 2πh2R I(R = 0). For the Milky Way, 1.5 × 1010 L = 2πh2R I(R = 0), and I(R) = I(R = 0) exp[−R/hR ]. We find I(R = 0) = LD /(2πh2R ) = 1.5 × 1010 L /(2π(4000pc)2 ) = 149 L pc−2 . Then I(R = 8kpc) ...
AS 701 - INTRODUCTION TO ASTROPHYSICS COURSE OVERVIEW - FALL 2013
... and gravitational physics, properties of stars, stellar structure, stellar evolution, dynamics of binary stars systems and star clusters, types of galaxies, galactic structure and dynamics, active galaxies and some cosmological topics. COURSE STRUCTURE AND PHILOSOPHY: The course is intended to provi ...
... and gravitational physics, properties of stars, stellar structure, stellar evolution, dynamics of binary stars systems and star clusters, types of galaxies, galactic structure and dynamics, active galaxies and some cosmological topics. COURSE STRUCTURE AND PHILOSOPHY: The course is intended to provi ...
Lecture4
... • Classification of Stars: Stars are classified by Spectral class (type), e.g., A1, and Luminosity class, e.g., V. ...
... • Classification of Stars: Stars are classified by Spectral class (type), e.g., A1, and Luminosity class, e.g., V. ...
Fill in the blanks of each frame using the list of missing words given
... Death of a High Mass Star ...
... Death of a High Mass Star ...
Sources with
... star formation is due to the rarity of the sources, the distance of the nearest examples Recent intense effort is providing larger samples of candidate HMYSOs based on infrared colours, ...
... star formation is due to the rarity of the sources, the distance of the nearest examples Recent intense effort is providing larger samples of candidate HMYSOs based on infrared colours, ...
with answers
... ● not all of the energy from the Sun comes from the proton-proton chain, meaning that some of the luminosity from the Sun comes from other nuclear reactions within the Sun. ● the reaction and consumption of hydrogen in a star is not linear or constant, but may fluctuate over time, especially as a st ...
... ● not all of the energy from the Sun comes from the proton-proton chain, meaning that some of the luminosity from the Sun comes from other nuclear reactions within the Sun. ● the reaction and consumption of hydrogen in a star is not linear or constant, but may fluctuate over time, especially as a st ...
Microsoft Word
... formation in the cluster may be non-coeval. The embedded cluster in the Nebulous Stream is found to be physically connected to the HII region. The YSOs located in the Nebulous Stream, embedded cluster and in the western region of Stock 8 have larger (H-K) excess in comparison to those located in th ...
... formation in the cluster may be non-coeval. The embedded cluster in the Nebulous Stream is found to be physically connected to the HII region. The YSOs located in the Nebulous Stream, embedded cluster and in the western region of Stock 8 have larger (H-K) excess in comparison to those located in th ...
University of Groningen Colliding winds in Wolf-Rayet
... where the lower mass stars (< 40 M ) undergo the red supergiant (RSG) phase and the higher ones (> 40 M ) undergo the luminous blue variable (LBV) phase. The Wolf-Rayet phase lasts for about 5 105 years, and the resulting supernovae are of Type Ib and Ic. Since the first detection by Wolf and Ra ...
... where the lower mass stars (< 40 M ) undergo the red supergiant (RSG) phase and the higher ones (> 40 M ) undergo the luminous blue variable (LBV) phase. The Wolf-Rayet phase lasts for about 5 105 years, and the resulting supernovae are of Type Ib and Ic. Since the first detection by Wolf and Ra ...
Hertzsprung–Russell diagram - Wikipedia, the free encyclopedia
... even that stars are largely composed of hydrogen (see metallicity), had yet to be discovered. Eddington managed to sidestep this problem by concentrating on the thermodynamics of radiative transport of energy in stellar interiors.[9] So, Eddington predicted that dwarf stars remain in an essentially ...
... even that stars are largely composed of hydrogen (see metallicity), had yet to be discovered. Eddington managed to sidestep this problem by concentrating on the thermodynamics of radiative transport of energy in stellar interiors.[9] So, Eddington predicted that dwarf stars remain in an essentially ...
B – V
... from Q (measured from UBV). Once (B – V)0 and (U – V)0 are known we find E(B – V) from (B – V). This only works for stars up to spectral type A0. Reason: The reddening happens to have the same slope as unreddened main sequence stars for late-type stars. Reddening free indices can also be defined for ...
... from Q (measured from UBV). Once (B – V)0 and (U – V)0 are known we find E(B – V) from (B – V). This only works for stars up to spectral type A0. Reason: The reddening happens to have the same slope as unreddened main sequence stars for late-type stars. Reddening free indices can also be defined for ...
Basic Assumptions About Convection The calculation of convection
... The quantity U is a measure of how efficient convection is at transporting energy. The convective cells have two characteristic timescales: one giving the length of time required to move the distance lm and deliver its energy, and the other describing how long it takes for the cell to lose its heat ...
... The quantity U is a measure of how efficient convection is at transporting energy. The convective cells have two characteristic timescales: one giving the length of time required to move the distance lm and deliver its energy, and the other describing how long it takes for the cell to lose its heat ...
The ages of pre-main-sequence stars
... The position of pre-main-sequence or protostars in the Hertzsprung±Russell diagram is often used to determine their mass and age by comparison with pre-main-sequence evolution tracks. On the assumption that the stellar models are accurate, we demonstrate that, if the metallicity is known, the mass o ...
... The position of pre-main-sequence or protostars in the Hertzsprung±Russell diagram is often used to determine their mass and age by comparison with pre-main-sequence evolution tracks. On the assumption that the stellar models are accurate, we demonstrate that, if the metallicity is known, the mass o ...
ALLAN SACHA BRUN Head of the Laboratory on Dynamics
... rotating Suns, using the Anelastic Spherical Harmonic (ASH) code. - Developed the MHD version of the ASH code. Computed 3--D nonlinear numerical simulations of rotating compressible magneto-convection using ASH to model key ingredients of the solar/stellar dynamo, such as dynamo in convective core o ...
... rotating Suns, using the Anelastic Spherical Harmonic (ASH) code. - Developed the MHD version of the ASH code. Computed 3--D nonlinear numerical simulations of rotating compressible magneto-convection using ASH to model key ingredients of the solar/stellar dynamo, such as dynamo in convective core o ...
More than You Ever Wanted to Know about Autoguiding
... What this means is that if you have 5 pixels of blur due to seeing, and the star moves three pixels during the exposure (or between corrections), the final blur will be the square root of 5^2 +3^2, or 5.83 pixels in length. Perpendicular to the movement the star is 5 pixels in diameter, so the final ...
... What this means is that if you have 5 pixels of blur due to seeing, and the star moves three pixels during the exposure (or between corrections), the final blur will be the square root of 5^2 +3^2, or 5.83 pixels in length. Perpendicular to the movement the star is 5 pixels in diameter, so the final ...