The Lives of Stars From Birth Through Middle Age (Chapter 9)
... 1. A helium-3 atom and a helium-4 atom combine to form a beryllium-7 (four protons and three neutrons) and a gamma ray. 2. A beryllium-7 atom captures an electron to become lithium-7 atom (three protons and four neutrons) and a neutrino. 3. The lithium-7 combines with a proton to form two helium-4 a ...
... 1. A helium-3 atom and a helium-4 atom combine to form a beryllium-7 (four protons and three neutrons) and a gamma ray. 2. A beryllium-7 atom captures an electron to become lithium-7 atom (three protons and four neutrons) and a neutrino. 3. The lithium-7 combines with a proton to form two helium-4 a ...
Measuring the Masses of Galaxies in the Sloan Digital Sky Survey
... distance ≈ z × age of Universe (z << 1) distance ≅ [z / (1+z)] × age of Universe e.g., for z = 0.0061, d = 0.00606 × 13.5 billion = 82 million light-years caveat: redshift must represent expansion of Universe, not orbital motion ...
... distance ≈ z × age of Universe (z << 1) distance ≅ [z / (1+z)] × age of Universe e.g., for z = 0.0061, d = 0.00606 × 13.5 billion = 82 million light-years caveat: redshift must represent expansion of Universe, not orbital motion ...
A Star is Born worksheet and key
... 10. How is a planetary nebula formed? When the outer layers of the red giant drift into space. 11. For how long do white dwarfs radiate their leftover heat? Billions of years. 12. How long is the life phase of a red supergiant? Millions of years. 13. What’s two differences between red giants and red ...
... 10. How is a planetary nebula formed? When the outer layers of the red giant drift into space. 11. For how long do white dwarfs radiate their leftover heat? Billions of years. 12. How long is the life phase of a red supergiant? Millions of years. 13. What’s two differences between red giants and red ...
The Hertzsprung-Russell Diagram
... sequence star. Hint: plot both stars on an HR diagram and note how their temperatures and luminosities compare. ...
... sequence star. Hint: plot both stars on an HR diagram and note how their temperatures and luminosities compare. ...
F03HW12
... the star clusters show us that when giants and supergiants are present in the clusters, there are few if any massive stars (O and B stars) on the main sequence. We can take models of many different masses of stars and determine what a cluster should look like after a given time. We can then compare ...
... the star clusters show us that when giants and supergiants are present in the clusters, there are few if any massive stars (O and B stars) on the main sequence. We can take models of many different masses of stars and determine what a cluster should look like after a given time. We can then compare ...
Volume 20 Number 10 September 2012
... In 2010, observers reported the most massive stars ever seen, - it exceeded what many astronomers thought was a maximum about 150 times the mass of the Sun. The heavyweight champs resided 160,000 light-years from Earth in Radcliffe 136, a dense star cluster within the Large Magellanic Cloud, the bri ...
... In 2010, observers reported the most massive stars ever seen, - it exceeded what many astronomers thought was a maximum about 150 times the mass of the Sun. The heavyweight champs resided 160,000 light-years from Earth in Radcliffe 136, a dense star cluster within the Large Magellanic Cloud, the bri ...
The Life Cycle of Stars Introduction Stars are huge spheres of very
... The sun will become a red giant before it dies. A red giant is a large, reddish star late in its life cycle. As the number of fusion reactions decreases, the pressure from the release of energy in the core of the sun drops, and the core will contract causing its temperature to rise. The outer layer ...
... The sun will become a red giant before it dies. A red giant is a large, reddish star late in its life cycle. As the number of fusion reactions decreases, the pressure from the release of energy in the core of the sun drops, and the core will contract causing its temperature to rise. The outer layer ...
Stellar Evolution
... We do not know that all stars, regardless of their size, eventually run out of fuel and collapse due to gravity Low Mass Stars – consume fuel at a slow rate, may remain on main-sequence for up to 100 billion years, end up collapsing into white dwarfs Medium Mass Stars – go into red-giant stage, foll ...
... We do not know that all stars, regardless of their size, eventually run out of fuel and collapse due to gravity Low Mass Stars – consume fuel at a slow rate, may remain on main-sequence for up to 100 billion years, end up collapsing into white dwarfs Medium Mass Stars – go into red-giant stage, foll ...
Microsoft Word 97
... 1. When did the Milky Way begin? _____________________________________________________ 2. Where does its name come from? ___________________________________________________ 3. What do we see when we look in the sky? _____________________________________________ 4. What does our galaxy look like from ...
... 1. When did the Milky Way begin? _____________________________________________________ 2. Where does its name come from? ___________________________________________________ 3. What do we see when we look in the sky? _____________________________________________ 4. What does our galaxy look like from ...
Document
... Stellar Properties/Evolution Review Sheet 1. It has been determined that all stars have the same general composition (90% H, 9% He, trace amounts of heavy elements). If this is the case, explain why stars of different temperatures show different spectral line patterns. ...
... Stellar Properties/Evolution Review Sheet 1. It has been determined that all stars have the same general composition (90% H, 9% He, trace amounts of heavy elements). If this is the case, explain why stars of different temperatures show different spectral line patterns. ...
Sample Exam for Final (with correct answers)
... (e) We know the times of giant explosions in these galaxies, then measure the time the light signals arrive at Earth. 23. The physical significance of the Hubble Constant is that it (a) corresponds to the time since the universe began to expand. ∗ (b) gives the total mass of the universe. (c) repres ...
... (e) We know the times of giant explosions in these galaxies, then measure the time the light signals arrive at Earth. 23. The physical significance of the Hubble Constant is that it (a) corresponds to the time since the universe began to expand. ∗ (b) gives the total mass of the universe. (c) repres ...
Unit 1 The Universe
... atmosphere expanding after active fusion ends. – Planetary nebula -forms when a star can no longer support itself by fusion reactions in its center – White dwarf -hot, dense core of matter that remains from the collapse of a low-mass star. It is about the size of Earth. – Black dwarf-white dwarf tha ...
... atmosphere expanding after active fusion ends. – Planetary nebula -forms when a star can no longer support itself by fusion reactions in its center – White dwarf -hot, dense core of matter that remains from the collapse of a low-mass star. It is about the size of Earth. – Black dwarf-white dwarf tha ...
Objectives
... • Less massive stars burn cooler and therefore can last longer • Our Sun will fuse hydrogen for about 10 billion years • Once a star’s Hydrogen supply runs out, fusion stops and the core begins to contract • At this time, the outer layers of hydrogen fuse at an incredible rate and the star expands t ...
... • Less massive stars burn cooler and therefore can last longer • Our Sun will fuse hydrogen for about 10 billion years • Once a star’s Hydrogen supply runs out, fusion stops and the core begins to contract • At this time, the outer layers of hydrogen fuse at an incredible rate and the star expands t ...
Astronomy 242: Review Questions #1 Distributed: February 10
... (a) Using the information in this diagram, estimate the range of surface gravities g for stars along the Main Sequence. Which end of the main sequence has the highest surface gravities? (b) Typical white dwarf stars have masses Mwd ≃ 1M⊙ . How do the surface gravities of white dwarf stars compare to ...
... (a) Using the information in this diagram, estimate the range of surface gravities g for stars along the Main Sequence. Which end of the main sequence has the highest surface gravities? (b) Typical white dwarf stars have masses Mwd ≃ 1M⊙ . How do the surface gravities of white dwarf stars compare to ...
www.astro.utu.fi
... after the gas supply runs out, as no new stars are created galaxy currently gets a few solar masses of gas per year, which dilutes the ISM metals and Helium will build up nicely H = 20%, He = 60%, metals = 20% leads to shorter stellar lifetimes ...
... after the gas supply runs out, as no new stars are created galaxy currently gets a few solar masses of gas per year, which dilutes the ISM metals and Helium will build up nicely H = 20%, He = 60%, metals = 20% leads to shorter stellar lifetimes ...
Pretest
... the entire galaxy. The most recent evidence suggests that the Milky Way is a barred-spiral galaxy, that is, a spiral galaxy with a large bar-shaped region of stars and gas passing through its center. S 8.4.a ...
... the entire galaxy. The most recent evidence suggests that the Milky Way is a barred-spiral galaxy, that is, a spiral galaxy with a large bar-shaped region of stars and gas passing through its center. S 8.4.a ...
A-105 Homework 1
... 18. (2 pts.) If the true distance to the center of our galaxy is found to be 7 kpc (instead of 8.5 kpc) and the orbital velocity of the sun is 220 km/s, what is the minimum mass of the galaxy? (Hints: Find the orbital period of the sun at 7 kpc, and then use Kepler’s 3rd law.) ...
... 18. (2 pts.) If the true distance to the center of our galaxy is found to be 7 kpc (instead of 8.5 kpc) and the orbital velocity of the sun is 220 km/s, what is the minimum mass of the galaxy? (Hints: Find the orbital period of the sun at 7 kpc, and then use Kepler’s 3rd law.) ...
Stars - Montville.net
... A neutron star is about 20 km in diameter and has the mass of about 1.4 times that of our Sun. This means that a neutron star is so dense that on Earth, one teaspoonful would weigh a billion tons! ...
... A neutron star is about 20 km in diameter and has the mass of about 1.4 times that of our Sun. This means that a neutron star is so dense that on Earth, one teaspoonful would weigh a billion tons! ...
Lec7_2D
... The main sequence makes sense. According to the blackbody law, hot things emit more light. But a star’s brightness also depends on its size – the larger the area, the more light that is emitted. The relationship between luminosity, radius, and temperature is ...
... The main sequence makes sense. According to the blackbody law, hot things emit more light. But a star’s brightness also depends on its size – the larger the area, the more light that is emitted. The relationship between luminosity, radius, and temperature is ...
Things to know: This meant as a guide to what you should know. I
... What are the definitions of parallax and light year? Know the concept of the cosmic calendar and the basic sequence of events including the formation of the Milky Way, the formation of the Sun and the busy events of December 31st. Your cosmic address What are the ages of the universe, of our galaxy, ...
... What are the definitions of parallax and light year? Know the concept of the cosmic calendar and the basic sequence of events including the formation of the Milky Way, the formation of the Sun and the busy events of December 31st. Your cosmic address What are the ages of the universe, of our galaxy, ...
Research Powerpoint - Department of Astronomy
... Prof. Sylvain Veilleux’s research interests center on understanding the nature, origin and impact of starburst/black-hole driven activity in galaxies, and on the formation and evolution of galaxies. The images here are from a review article co-authored by Prof. Veilleux which discusses the ‘winds’ ...
... Prof. Sylvain Veilleux’s research interests center on understanding the nature, origin and impact of starburst/black-hole driven activity in galaxies, and on the formation and evolution of galaxies. The images here are from a review article co-authored by Prof. Veilleux which discusses the ‘winds’ ...
April11
... • All Type 1a supernova have similar peak luminosities, and so can be used to measure the distance to the clusters or galaxies that contain them! ...
... • All Type 1a supernova have similar peak luminosities, and so can be used to measure the distance to the clusters or galaxies that contain them! ...
Lec 25.2- STELLAR EVOLUTION SUMMARY
... be gravitationally bound. At this point, the cloud collapses under the influence of its own gravity. At first, it contracts rapidly because energy thereby released is easily radiated outward. Eventually, the cloud grows dense enough to become opaque to (block) its own radiation. This causes the clou ...
... be gravitationally bound. At this point, the cloud collapses under the influence of its own gravity. At first, it contracts rapidly because energy thereby released is easily radiated outward. Eventually, the cloud grows dense enough to become opaque to (block) its own radiation. This causes the clou ...
Lifetimes of stars
... Stellar Lifetimes • The Sun (and all stars) will eventually run out of fuel (hydrogen in regions where it is hot enough for fusion). • If all the hydrogen in the Sun could fuse to helium, the Sun’s lifetime would be 100 billion years. • But, by the time about 10% of the Sun’s H has been converted in ...
... Stellar Lifetimes • The Sun (and all stars) will eventually run out of fuel (hydrogen in regions where it is hot enough for fusion). • If all the hydrogen in the Sun could fuse to helium, the Sun’s lifetime would be 100 billion years. • But, by the time about 10% of the Sun’s H has been converted in ...
H II region
An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.