Standards
... their statement to the class. If they did not make a correct match – try again later!! This will lead to discussion about each statement. The students will need to write down the terms and concepts to have for reference and study. The Stars - Types of stars Ask students how they think astronomers gr ...
... their statement to the class. If they did not make a correct match – try again later!! This will lead to discussion about each statement. The students will need to write down the terms and concepts to have for reference and study. The Stars - Types of stars Ask students how they think astronomers gr ...
Unit 13―The “Fixed” Stars
... Until we know more about whether some stars are inherently bigger than others or some stars “burn” by a faster process, we cannot be 100% certain, but a good first guess is the drop in brightness corresponds to increasing distance from the Earth. That makes sense if you imagine that stars have some ...
... Until we know more about whether some stars are inherently bigger than others or some stars “burn” by a faster process, we cannot be 100% certain, but a good first guess is the drop in brightness corresponds to increasing distance from the Earth. That makes sense if you imagine that stars have some ...
The Hertzsprung-Russell Diagramm
... Figure 7: Russell’s first diagram, with spectral types listed along the top and absolute magnitudes on the left-hand side. [CO] M ost stars are in a band in the HR-diagram that consists of hot, bright O-stars at the upper left hand corner and the cool, dim stars at the lower right hand corner. This ...
... Figure 7: Russell’s first diagram, with spectral types listed along the top and absolute magnitudes on the left-hand side. [CO] M ost stars are in a band in the HR-diagram that consists of hot, bright O-stars at the upper left hand corner and the cool, dim stars at the lower right hand corner. This ...
The Life of a Star
... of rotation and magnetic elds) and hydrostatic equilibrium. Under these assumptions a star can be described by the run of four structure variables { r, T , P , Lr { with the Lagrangian coordinate m. We will derive the corresponding four partial dierential equations. From the discussion of those se ...
... of rotation and magnetic elds) and hydrostatic equilibrium. Under these assumptions a star can be described by the run of four structure variables { r, T , P , Lr { with the Lagrangian coordinate m. We will derive the corresponding four partial dierential equations. From the discussion of those se ...
IAU-Perraut-2013 - Putting A Stars into Context
... Science drivers A-F stars are an ideal laboratory for studying physical processes ...
... Science drivers A-F stars are an ideal laboratory for studying physical processes ...
Astr 102 Lec 6: Basic Properties of Stars
... far these street lights are, you can figure out how luminous the light bulbs are. ...
... far these street lights are, you can figure out how luminous the light bulbs are. ...
The Sun and Stars 4.1 Energy formation and layers of the Sun 4.2
... anything been identified that can travel at this speed other than the photons of light energy. Though it is easy to believe that the light from stars reaches us "instantaneously," like that of a light bulb being turned on, it is only with very distant luminescent objects that we can notice that ligh ...
... anything been identified that can travel at this speed other than the photons of light energy. Though it is easy to believe that the light from stars reaches us "instantaneously," like that of a light bulb being turned on, it is only with very distant luminescent objects that we can notice that ligh ...
LAB #3 - GEOCITIES.ws
... LAB. You will begin lab with a short quiz on these questions. What are Magnitudes? Because what we know about stars is due solely to our analysis of their light, it is very important to develop further the idea of stellar magnitude, or how bright a star is. When the Greeks scientist Hipparcos determ ...
... LAB. You will begin lab with a short quiz on these questions. What are Magnitudes? Because what we know about stars is due solely to our analysis of their light, it is very important to develop further the idea of stellar magnitude, or how bright a star is. When the Greeks scientist Hipparcos determ ...
Abundances of RGB stars in NGC 6752 Grundahl
... The primordial scenario, and variations on it, has been proposed and discussed several times before in the literature (see for example Cottrell & Da Costa 1981, and Cannon et al. 1998). The small star–to–star scatter in the iron peak elements (as observed in this work) indicates that the contributio ...
... The primordial scenario, and variations on it, has been proposed and discussed several times before in the literature (see for example Cottrell & Da Costa 1981, and Cannon et al. 1998). The small star–to–star scatter in the iron peak elements (as observed in this work) indicates that the contributio ...
Labeling the HR Diagram - Mastering Physics Answers
... Hint 2. Can you determine the luminosity of a street light on a foggy night? Suppose you measure the apparent brightness of a street light that is located 100 meters away from you. If it is a foggy night and you apply the inverse square law for light, then the luminosity you calculate for the street ...
... Hint 2. Can you determine the luminosity of a street light on a foggy night? Suppose you measure the apparent brightness of a street light that is located 100 meters away from you. If it is a foggy night and you apply the inverse square law for light, then the luminosity you calculate for the street ...
Chapter 13 Measuring the properties of stars
... Which of the following statements would explain the fact that larger molecules, such as amino acids, do not produce spectral lines in the OBAFGKM classification? A. Larger molecules require higher temperatures to show absorption lines. B. The spectra of hydrogen and helium are sufficient to classif ...
... Which of the following statements would explain the fact that larger molecules, such as amino acids, do not produce spectral lines in the OBAFGKM classification? A. Larger molecules require higher temperatures to show absorption lines. B. The spectra of hydrogen and helium are sufficient to classif ...
Globular Clusters
... contain one of the most popular intrinsic variable stars, the so-called RR LYRAE STARS. These stars have light variation amplitudes less than a couple of magnitudes and periods ranging from 0.2 to 1.1 days. Since their mean absolute magnitude is constant and fairly independent of metallicity (to wit ...
... contain one of the most popular intrinsic variable stars, the so-called RR LYRAE STARS. These stars have light variation amplitudes less than a couple of magnitudes and periods ranging from 0.2 to 1.1 days. Since their mean absolute magnitude is constant and fairly independent of metallicity (to wit ...
Age-Dating of Young Stars and Stellar Systems
... Often it is implicitly assumed that massive stars are hot. Yet they spend a few % of their lifetime as cool, core-He burning objects in the red part of the HRD. These stars are observationally identified as RSGs, or giants if they undergo core-helium or helium-shell flashes at masses below ∼8 M . I ...
... Often it is implicitly assumed that massive stars are hot. Yet they spend a few % of their lifetime as cool, core-He burning objects in the red part of the HRD. These stars are observationally identified as RSGs, or giants if they undergo core-helium or helium-shell flashes at masses below ∼8 M . I ...
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 ...
6.1 Introduction
... Much of our knowledge of the physical conditions of astrophysical systems relies on spectroscopic observations. The absorption lines formed in the atmospheres of stars contain a wealth of information, on the temperature, gravity, rotational velocity and chemical composition of the star. The last one ...
... Much of our knowledge of the physical conditions of astrophysical systems relies on spectroscopic observations. The absorption lines formed in the atmospheres of stars contain a wealth of information, on the temperature, gravity, rotational velocity and chemical composition of the star. The last one ...
Star
A star is a luminous sphere of plasma held together by its own gravity. The nearest star to Earth is the Sun. Other stars are visible from Earth during the night, appearing as a multitude of fixed luminous points in the sky due to their immense distance from Earth. Historically, the most prominent stars were grouped into constellations and asterisms, and the brightest stars gained proper names. Extensive catalogues of stars have been assembled by astronomers, which provide standardized star designations.For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen into helium in its core, releasing energy that traverses the star's interior and then radiates into outer space. Once the hydrogen in the core of a star is nearly exhausted, almost all naturally occurring elements heavier than helium are created by stellar nucleosynthesis during the star's lifetime and, for some stars, by supernova nucleosynthesis when it explodes. Near the end of its life, a star can also contain degenerate matter. Astronomers can determine the mass, age, metallicity (chemical composition), and many other properties of a star by observing its motion through space, luminosity, and spectrum respectively. The total mass of a star is the principal determinant of its evolution and eventual fate. Other characteristics of a star, including diameter and temperature, change over its life, while the star's environment affects its rotation and movement. A plot of the temperature of many stars against their luminosities, known as a Hertzsprung–Russell diagram (H–R diagram), allows the age and evolutionary state of a star to be determined.A star's life begins with the gravitational collapse of a gaseous nebula of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Once the stellar core is sufficiently dense, hydrogen becomes steadily converted into helium through nuclear fusion, releasing energy in the process. The remainder of the star's interior carries energy away from the core through a combination of radiative and convective processes. The star's internal pressure prevents it from collapsing further under its own gravity. Once the hydrogen fuel at the core is exhausted, a star with at least 0.4 times the mass of the Sun expands to become a red giant, in some cases fusing heavier elements at the core or in shells around the core. The star then evolves into a degenerate form, recycling a portion of its matter into the interstellar environment, where it will contribute to the formation of a new generation of stars with a higher proportion of heavy elements. Meanwhile, the core becomes a stellar remnant: a white dwarf, a neutron star, or (if it is sufficiently massive) a black hole.Binary and multi-star systems consist of two or more stars that are gravitationally bound, and generally move around each other in stable orbits. When two such stars have a relatively close orbit, their gravitational interaction can have a significant impact on their evolution. Stars can form part of a much larger gravitationally bound structure, such as a star cluster or a galaxy.