astronomy practice test ch 9
... ____ 14. Giant stars are members of luminosity class III. ____ 15. If a star is twice as hot as the sun and only half the sun's diameter, it will be less luminous than the sun. ____ 16. The method of spectroscopic parallax cannot be applied to stars beyond about 100 pc. ____ 17. The most common kind ...
... ____ 14. Giant stars are members of luminosity class III. ____ 15. If a star is twice as hot as the sun and only half the sun's diameter, it will be less luminous than the sun. ____ 16. The method of spectroscopic parallax cannot be applied to stars beyond about 100 pc. ____ 17. The most common kind ...
13.5 The HR Diagram By the early 1900s, astronomers had learned
... In 1912, the Danish astronomer Ejnar Hertzsprung and the American astronomer Henry Norris Russell working independently found that if stars are plotted on a diagram according to their luminosity and their temperature (or, equivalently, spectral type), then most of them lie along a smooth curve. The ...
... In 1912, the Danish astronomer Ejnar Hertzsprung and the American astronomer Henry Norris Russell working independently found that if stars are plotted on a diagram according to their luminosity and their temperature (or, equivalently, spectral type), then most of them lie along a smooth curve. The ...
Galaxies, Cosmology and the Accelera`ng Universe
... Distribu6on of Stars • Even though hot bright stars are rare, they make more light than all the other stars combined • In a cube 10 parsecs (32 light years) on a side – In the spiral ar ...
... Distribu6on of Stars • Even though hot bright stars are rare, they make more light than all the other stars combined • In a cube 10 parsecs (32 light years) on a side – In the spiral ar ...
PSU/TCfA search for planets around evolved stars
... Searches for planets around massive stars are essential for developing general understanding of planet formation and evolution of the planetary systems. The main objective of the PSU-TCfA Search for Planets Around Evolved Stars is detection of planets around G-K subgiants and giants through precisio ...
... Searches for planets around massive stars are essential for developing general understanding of planet formation and evolution of the planetary systems. The main objective of the PSU-TCfA Search for Planets Around Evolved Stars is detection of planets around G-K subgiants and giants through precisio ...
Lecture 13, PPT version
... Globular clusters have short, stubby main sequences that “turn off” to the red giant region. The “turn off” point tells you the approximate age. ...
... Globular clusters have short, stubby main sequences that “turn off” to the red giant region. The “turn off” point tells you the approximate age. ...
Constituents of the Milky Way
... Population I: objects associated with recent star formation Population II: objects with no connection to recent star formation Thus, short-lived stars, open clusters, dark clouds, H II regions, etc., are all Population I. Conversely, groups of old stars, globular clusters, etc., are Population I ...
... Population I: objects associated with recent star formation Population II: objects with no connection to recent star formation Thus, short-lived stars, open clusters, dark clouds, H II regions, etc., are all Population I. Conversely, groups of old stars, globular clusters, etc., are Population I ...
Chapter 12 Stellar Evolution
... B. by other fusion reactions. C. by gravitational contraction. D. none of these; the fusion reactions stop. ...
... B. by other fusion reactions. C. by gravitational contraction. D. none of these; the fusion reactions stop. ...
EXAM II REVIEW
... Equations already mentioned EM spectrum HR diagram (most time on main sequence) Life cycle of a low & high mass stars Stellar Cutoffs – 8 M, 2 M, 1.4 M, 3 M Types of spectra & how they are formed Structure of our SUN What makes the sun shine? Evidence for nuclear fusion in the core. • H fusion – (4 ...
... Equations already mentioned EM spectrum HR diagram (most time on main sequence) Life cycle of a low & high mass stars Stellar Cutoffs – 8 M, 2 M, 1.4 M, 3 M Types of spectra & how they are formed Structure of our SUN What makes the sun shine? Evidence for nuclear fusion in the core. • H fusion – (4 ...
Chap. 02
... • Photometry measures the apparent brightness of a star • Standard filters, such as U (Ultraviolet), B (Blue) and V (Visual, yellow-green) filters, • Color ratios of a star are the ratios of brightness values obtained through different filters • These ratios are a good measure of the star’s surface ...
... • Photometry measures the apparent brightness of a star • Standard filters, such as U (Ultraviolet), B (Blue) and V (Visual, yellow-green) filters, • Color ratios of a star are the ratios of brightness values obtained through different filters • These ratios are a good measure of the star’s surface ...
Stars, Galaxies, and the Universe Section 1 Distances to Stars
... • Most stars have several types of actual motion. • Stars move across the sky (seen only for close stars). • Some stars may revolve around another star. • Stars either move away from or toward our solar system. ...
... • Most stars have several types of actual motion. • Stars move across the sky (seen only for close stars). • Some stars may revolve around another star. • Stars either move away from or toward our solar system. ...
GEARS Workshop Monday - Georgia Southern University
... Fe+19 (19 times ionized iron) • HI = neutral hydrogen • HII = singly ionized hydrogen ...
... Fe+19 (19 times ionized iron) • HI = neutral hydrogen • HII = singly ionized hydrogen ...
Triangulation Trigonometric Parallax
... – Therefore, as one moves up the H-R diagram, a star’s radius must become bigger – On the other hand, for a given luminosity, the larger the radius, the smaller the temperature – Therefore, as one moves right on the H-R diagram, a star’s radius must increase – The net effect of this is that the smal ...
... – Therefore, as one moves up the H-R diagram, a star’s radius must become bigger – On the other hand, for a given luminosity, the larger the radius, the smaller the temperature – Therefore, as one moves right on the H-R diagram, a star’s radius must increase – The net effect of this is that the smal ...
The Death of a Low Mass Star
... – Carbon and oxygen brought to the surface – In consequence, molecular absorption bands often seen in the spectra of AGB stars – Soot coccoons may also form around such ...
... – Carbon and oxygen brought to the surface – In consequence, molecular absorption bands often seen in the spectra of AGB stars – Soot coccoons may also form around such ...
Become a Member - Department of Physics and Astronomy
... Cecilia Payne-Gaposchkin at Harvard When Cecilia Payne began her study of stellar spectra, scientists believed that the relative abundance of elements in the atmospheres of the Sun and the stars was similar to that in Earth’s crust. In 1889, geochemist Frank Wigglesworth Clarke’s The Relative Abunda ...
... Cecilia Payne-Gaposchkin at Harvard When Cecilia Payne began her study of stellar spectra, scientists believed that the relative abundance of elements in the atmospheres of the Sun and the stars was similar to that in Earth’s crust. In 1889, geochemist Frank Wigglesworth Clarke’s The Relative Abunda ...
Starlight and Atoms - School District of Clayton
... many stars have no lines for hydrogen or helium in their spectrum. What causes this apparent contradiction? a. Spectral lines are created in the lower atmospheres of stars, and for many stars hydrogen and helium are hidden below the atmosphere. b. The upper layers of a star contain hot low-density g ...
... many stars have no lines for hydrogen or helium in their spectrum. What causes this apparent contradiction? a. Spectral lines are created in the lower atmospheres of stars, and for many stars hydrogen and helium are hidden below the atmosphere. b. The upper layers of a star contain hot low-density g ...
V: 0
... The student is expected to explore how different wavelengths of the electromagnetic spectrum such as light and radio waves are used to gain information about distances and properties of components in the universe. ...
... The student is expected to explore how different wavelengths of the electromagnetic spectrum such as light and radio waves are used to gain information about distances and properties of components in the universe. ...
this PDF file - University of Leicester Open Journals
... in an eternal and unchanging universe to one where even the stars themselves will one day fade away. Unlike most of the stars we can see with the naked eye, white dwarfs no longer generate heat via nuclear fusion. These stars still give off light as the cooling process takes billions of years. It is ...
... in an eternal and unchanging universe to one where even the stars themselves will one day fade away. Unlike most of the stars we can see with the naked eye, white dwarfs no longer generate heat via nuclear fusion. These stars still give off light as the cooling process takes billions of years. It is ...
Lecture 3
... • The different spectral types were recognized in the early 1800s. • Why do some stars show strong absorption due to hydrogen and others don’t. • The obvious solution would be to imagine that it is due to differences in the chemical composition of stars. Nope! ...
... • The different spectral types were recognized in the early 1800s. • Why do some stars show strong absorption due to hydrogen and others don’t. • The obvious solution would be to imagine that it is due to differences in the chemical composition of stars. Nope! ...
STARS AND PLANETS: A NEW SET OF MIDDLE SCHOOL
... the lifetimes of different masses of stars to each other and to the geologic timeline for the Earth. Students then make predictions about what classes of main sequence stars might have planets with interesting (as defined by the students) life forms, assuming the history of life on Earth is typical. ...
... the lifetimes of different masses of stars to each other and to the geologic timeline for the Earth. Students then make predictions about what classes of main sequence stars might have planets with interesting (as defined by the students) life forms, assuming the history of life on Earth is typical. ...
TMSP Stellar Evolution & Life
... i. looking directly at the light source (produces a bright coloured line against a black background; this is called an emission spectrum) How does this happen? •Each of the absorption and emission spectra are produced by specific energies (wavelengths) of light interacting with the atoms that make u ...
... i. looking directly at the light source (produces a bright coloured line against a black background; this is called an emission spectrum) How does this happen? •Each of the absorption and emission spectra are produced by specific energies (wavelengths) of light interacting with the atoms that make u ...
Basic properties of stars
... Consider main sequence stars that convert hydrogen into helium using the proton-proton cycle. The luminosity of the star is a measure of how many Joules of energy it gives off per unit time. The total energy given off in the main sequence lifetime of the star is: luminosity (J/sec) X lifetime of st ...
... Consider main sequence stars that convert hydrogen into helium using the proton-proton cycle. The luminosity of the star is a measure of how many Joules of energy it gives off per unit time. The total energy given off in the main sequence lifetime of the star is: luminosity (J/sec) X lifetime of st ...
OBAFGKM(LT) extra credit due today. Mid
... “Luminosity class” is added to the spectral type, telling you if it’s main-sequence (a “dwarf”, V), giant (III), or super-giant star (I). The sun is a G2 V. Stars occur in smaller “open” and giant “globular” clusters, with hundreds to millions of stars. Stars in clusters born at the same time, so th ...
... “Luminosity class” is added to the spectral type, telling you if it’s main-sequence (a “dwarf”, V), giant (III), or super-giant star (I). The sun is a G2 V. Stars occur in smaller “open” and giant “globular” clusters, with hundreds to millions of stars. Stars in clusters born at the same time, so th ...
Shining Light on the Stars: The Hertzsprung-Russell
... sky from Earth are located here. But what about all the stars in the nearby solar neighborhood, most of which are too faint to be seen without a telescope? We immediately see that these two groups of stars lie in completely different parts of the HR diagram. The local group of stars within 25 light ...
... sky from Earth are located here. But what about all the stars in the nearby solar neighborhood, most of which are too faint to be seen without a telescope? We immediately see that these two groups of stars lie in completely different parts of the HR diagram. The local group of stars within 25 light ...
Observational properties of stars
... How do we track/follow the evolution of a star? Basic answer – it isn’t possible. Stars evolve very slowly so it is not possible to see significant changes in any stars during your life. There are occasional sporadic changes, like supernovae, but those are rare. Stars will take millions or billions ...
... How do we track/follow the evolution of a star? Basic answer – it isn’t possible. Stars evolve very slowly so it is not possible to see significant changes in any stars during your life. There are occasional sporadic changes, like supernovae, but those are rare. Stars will take millions or billions ...
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.