Measuring the Stars Section 29.2
... Temperature is also related to luminosity and absolute magnitude. Hotter stars put out more light than stars with lower temperatures. Because the temperature of a star is not affected by its distance, by measuring the temperature and luminosity, distance is known. ...
... Temperature is also related to luminosity and absolute magnitude. Hotter stars put out more light than stars with lower temperatures. Because the temperature of a star is not affected by its distance, by measuring the temperature and luminosity, distance is known. ...
20_LectureOutline
... is now blue-white. Why? Could there have been an intervening dust cloud? (Then where is it?) Could its companion have been a red giant? (It became a white dwarf very quickly, then!) ...
... is now blue-white. Why? Could there have been an intervening dust cloud? (Then where is it?) Could its companion have been a red giant? (It became a white dwarf very quickly, then!) ...
Chapter 16 Star Birth
... • Without CO molecules to provide cooling, the clouds that formed the first stars had to be considerably warmer than today’s molecular clouds • The first stars must therefore have been more massive than most of today’s stars, for gravity to overcome pressure ...
... • Without CO molecules to provide cooling, the clouds that formed the first stars had to be considerably warmer than today’s molecular clouds • The first stars must therefore have been more massive than most of today’s stars, for gravity to overcome pressure ...
Chapter 16 Star Birth Where do stars form? Star
... • Elements like carbon and oxygen had not yet been made when the first stars formed • Without CO molecules to provide cooling, the clouds that formed the first stars had to be considerably warmer than today’s molecular clouds • The first stars must therefore have been more massive than most of today ...
... • Elements like carbon and oxygen had not yet been made when the first stars formed • Without CO molecules to provide cooling, the clouds that formed the first stars had to be considerably warmer than today’s molecular clouds • The first stars must therefore have been more massive than most of today ...
Review 3 (11-18-10)
... Apparent brightness: how bright a star looks in the sky The inverse-square Law: light from stars gets fainter as the inverse square of the distance (brightness proportional to 1/d2). If we know the apparent brightness and the distance to a star we can calculate its absolute (intrinsic) brightness ...
... Apparent brightness: how bright a star looks in the sky The inverse-square Law: light from stars gets fainter as the inverse square of the distance (brightness proportional to 1/d2). If we know the apparent brightness and the distance to a star we can calculate its absolute (intrinsic) brightness ...
poster
... Figure 3: FUV emission lines observed with FUSE in CTTS and best fit Gaussian profiles ordered by the shift in the O vi 1032 Å line. For RU Lup an additional absorption component is used. ...
... Figure 3: FUV emission lines observed with FUSE in CTTS and best fit Gaussian profiles ordered by the shift in the O vi 1032 Å line. For RU Lup an additional absorption component is used. ...
chapter16StarBirth
... • Without CO molecules to provide cooling, the clouds that formed the first stars had to be considerably warmer than today’s molecular clouds • The first stars must therefore have been more massive than most of today’s stars, for gravity to overcome pressure ...
... • Without CO molecules to provide cooling, the clouds that formed the first stars had to be considerably warmer than today’s molecular clouds • The first stars must therefore have been more massive than most of today’s stars, for gravity to overcome pressure ...
Agenda - Relativity Group
... skins inside the star. However, since fusion of iron uses up energy instead of releasing energy, an iron core cannot support the weight of the outer layers. The collapse of this core — which occurs in a fraction of a second — results in a supernova that nearly obliterates the star (perhaps leaving a ...
... skins inside the star. However, since fusion of iron uses up energy instead of releasing energy, an iron core cannot support the weight of the outer layers. The collapse of this core — which occurs in a fraction of a second — results in a supernova that nearly obliterates the star (perhaps leaving a ...
Hertzsprung Rusell Diagram KLT
... Describe, briefly the sequence of events which occur in the formation of a star, such as our Sun, from interstellar dust and gas clouds. In your answer, you should make it clear how the steps in the process and sequenced. ...
... Describe, briefly the sequence of events which occur in the formation of a star, such as our Sun, from interstellar dust and gas clouds. In your answer, you should make it clear how the steps in the process and sequenced. ...
Cool Star Atmospheres and Spectra for GAIA
... at hydrostatic equilibrium and LTE. We know from detailed observations and modeling of the Sun that hydrodynamics, magnetic fields, non-LTE, all must enter the picture if we have the ambition of reproducing the solar spectrum. We know that our line lists are incomplete, or suffer from uncertainties ...
... at hydrostatic equilibrium and LTE. We know from detailed observations and modeling of the Sun that hydrodynamics, magnetic fields, non-LTE, all must enter the picture if we have the ambition of reproducing the solar spectrum. We know that our line lists are incomplete, or suffer from uncertainties ...
Slide 1
... literature … it produces no observable differences until bolometric luminosities below the largest magnitude globular cluster stars ...
... literature … it produces no observable differences until bolometric luminosities below the largest magnitude globular cluster stars ...
Finish up Sun and begin Stars of the Sun Test 1 Study
... measure as stars are so far away Closest Alpha Centauri 4.3 light years = 4 x 1013 km (1 AU = distance Earth to Sun = 8 light minutes) • Close stars use stellar parallax (heliocentric parallax or triangulation same meaning) • Can “easily” measure distance using parallax to a few 100 LY. Need teles ...
... measure as stars are so far away Closest Alpha Centauri 4.3 light years = 4 x 1013 km (1 AU = distance Earth to Sun = 8 light minutes) • Close stars use stellar parallax (heliocentric parallax or triangulation same meaning) • Can “easily” measure distance using parallax to a few 100 LY. Need teles ...
Here
... • Imagine a source emitting light uniformly over all directions. Also imagine a series of concentric spheres centered on the light source. • The energy passing through each sphere is the same! ...
... • Imagine a source emitting light uniformly over all directions. Also imagine a series of concentric spheres centered on the light source. • The energy passing through each sphere is the same! ...
Spatial distribution of stars in the Milky Way
... •This may seem anomalous because they are later type than F •But the sample is dominated by giants, which can be observed to (on average) large distances in the disk Note that the faintest stars, M dwarfs, are restricted to the inner 20 pc or so, while progressively brighter stars are seen fill prog ...
... •This may seem anomalous because they are later type than F •But the sample is dominated by giants, which can be observed to (on average) large distances in the disk Note that the faintest stars, M dwarfs, are restricted to the inner 20 pc or so, while progressively brighter stars are seen fill prog ...
Evidence for a signature of the galactic bar in the solar neighbourhood
... inner disc. Its (u, v) plane displayed in Fig. 2 shows an intriguing two clump distribution. These two clumps have similar age and abundance distributions, despite the presently outward moving one involves 1.5 times more stars. In addition, if we consider the (u, v) plane for a subsample of Fig.1 wi ...
... inner disc. Its (u, v) plane displayed in Fig. 2 shows an intriguing two clump distribution. These two clumps have similar age and abundance distributions, despite the presently outward moving one involves 1.5 times more stars. In addition, if we consider the (u, v) plane for a subsample of Fig.1 wi ...
Reach for the Stars – Div. B
... 1a. Stars are categorized by their spectral class 1b. Hertzsprung-Russell (H-R) diagram is a way to represent the evolution of stars 2. The Main sequence is the location of stars on the H-R diagram where stars spend most of their lives: Hydrogen fusing to Helium in the star’s core 3. Stars remain s ...
... 1a. Stars are categorized by their spectral class 1b. Hertzsprung-Russell (H-R) diagram is a way to represent the evolution of stars 2. The Main sequence is the location of stars on the H-R diagram where stars spend most of their lives: Hydrogen fusing to Helium in the star’s core 3. Stars remain s ...
preliminary version - University of Exeter
... clear why they show a uni-modal distribution, nor why they are rotating more rapidly than the high mass stars (but see Barnes 2003[9]). Furthermore, the low mass stars do not fit into the evolutionary sequence above: the distributions in NGC 2264 and IC 348 are very similar, despite the very differe ...
... clear why they show a uni-modal distribution, nor why they are rotating more rapidly than the high mass stars (but see Barnes 2003[9]). Furthermore, the low mass stars do not fit into the evolutionary sequence above: the distributions in NGC 2264 and IC 348 are very similar, despite the very differe ...
File - Adriana Romo
... Scientist: There supported by electron degeneracy and they are found to the lower left of the main sequence of the H-R diagram. Interviewer: What do white dwarfs represent? Scientist: They represent a stable phase in which stars of less than 1.4 solar masses line out the rest of their lives. ...
... Scientist: There supported by electron degeneracy and they are found to the lower left of the main sequence of the H-R diagram. Interviewer: What do white dwarfs represent? Scientist: They represent a stable phase in which stars of less than 1.4 solar masses line out the rest of their lives. ...
Star-S_Teacher_Guide - The University of Texas at Dallas
... 2. How much bigger or smaller than the Sun is each star? How does your answer change if you compare volumes instead of diameters? This question provides a good opportunity to bring in mathematic concepts related to diameter and volume. ...
... 2. How much bigger or smaller than the Sun is each star? How does your answer change if you compare volumes instead of diameters? This question provides a good opportunity to bring in mathematic concepts related to diameter and volume. ...
Ch 13 Death of Stars(4-5?-13)
... stops the collapse and produces an object so compact that escape velocity is higher than speed of light; hence, not even light can escape. •NOTE: these are the masses of the dead stars NOT the masses they had when they were on the main sequence ...
... stops the collapse and produces an object so compact that escape velocity is higher than speed of light; hence, not even light can escape. •NOTE: these are the masses of the dead stars NOT the masses they had when they were on the main sequence ...
Ch. 13 Death of Stars(11-16-10)-3
... stops the collapse and produces an object so compact that escape velocity is higher than speed of light; hence, not even light can escape. •NOTE: these are the masses of the dead stars NOT the masses they had when they were on the main sequence ...
... stops the collapse and produces an object so compact that escape velocity is higher than speed of light; hence, not even light can escape. •NOTE: these are the masses of the dead stars NOT the masses they had when they were on the main sequence ...
Slide 1
... •Ellipticals have lots of globular clusters (about twice that of disk galaxies) •these fall into two groups based on color •color determined by metallicity, with more metal-rich GCs (redder) possibly the result of galaxy mergers •Ellipticals have much less cool, atomic gas than spiral galaxies •< 1 ...
... •Ellipticals have lots of globular clusters (about twice that of disk galaxies) •these fall into two groups based on color •color determined by metallicity, with more metal-rich GCs (redder) possibly the result of galaxy mergers •Ellipticals have much less cool, atomic gas than spiral galaxies •< 1 ...
color-stellar mass diagram
... luminosity, mass, color, morphology, stellar population of galaxies are strongly related. analysis of such properties in the cosmic time started first with the study of the luminosity function but later included galaxy counts as function of the various parameters however, almost all these properties ...
... luminosity, mass, color, morphology, stellar population of galaxies are strongly related. analysis of such properties in the cosmic time started first with the study of the luminosity function but later included galaxy counts as function of the various parameters however, almost all these properties ...
Star
... almost all of the hydrogen atoms within its core have fused into helium atoms. • A star’s shell of gases grows cooler as it expands. As the gases in the outer shell become cooler, they begin to glow with a reddish color. These stars are known as giants. ...
... almost all of the hydrogen atoms within its core have fused into helium atoms. • A star’s shell of gases grows cooler as it expands. As the gases in the outer shell become cooler, they begin to glow with a reddish color. These stars are known as giants. ...
Giant “Pulsar” Studies with the Compact Array Abstract
... al. (2011, submitted to MNRAS) suggest that the emission is instead ducted through cavities along the field lines to higher emission heights, and then radiated. Further wide-band observations are required to distinguish between these models. Such observations are being carried out using the new Comp ...
... al. (2011, submitted to MNRAS) suggest that the emission is instead ducted through cavities along the field lines to higher emission heights, and then radiated. Further wide-band observations are required to distinguish between these models. Such observations are being carried out using the new Comp ...
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.