Friday Feb 25th, 2000
... Now it is best to just use the light travel time - 17 years across this box, we say it is 17 light years wide. (This is 2.6X1010 miles across … etc.) ...
... Now it is best to just use the light travel time - 17 years across this box, we say it is 17 light years wide. (This is 2.6X1010 miles across … etc.) ...
General Introduction 1. Luminosity, Flux and Magnitude The
... The evolution of the Sun is shown schematically in Fig. 7.3. The red giant phase occurs after the interior of the Sun is exhausted of hydrogen and helium burning initiates. The Sun is not massive enough to burn elements beyond He, so after shedding roughly half its mass in a violent wind leading to ...
... The evolution of the Sun is shown schematically in Fig. 7.3. The red giant phase occurs after the interior of the Sun is exhausted of hydrogen and helium burning initiates. The Sun is not massive enough to burn elements beyond He, so after shedding roughly half its mass in a violent wind leading to ...
Chapter 2 Discovering the Universe for Yourself
... The Greeks knew that the lack of observable parallax could mean one of two things: 1. Stars are so far away that stellar parallax is too small to notice with the naked eye 2. Earth does not orbit Sun; it is the center of the universe With rare exceptions such as Aristarchus, the Greeks rejected the ...
... The Greeks knew that the lack of observable parallax could mean one of two things: 1. Stars are so far away that stellar parallax is too small to notice with the naked eye 2. Earth does not orbit Sun; it is the center of the universe With rare exceptions such as Aristarchus, the Greeks rejected the ...
The Naked Eye Era
... career to astrometry—the precise measurement of star positions. Tycho was inspired by two celestial events early in his career; the appearance of bright new star in 1572, and of a comet in 1577. Aristotle’s view that the stars and the constellations were forever unchanging still held sway in Tycho’s ...
... career to astrometry—the precise measurement of star positions. Tycho was inspired by two celestial events early in his career; the appearance of bright new star in 1572, and of a comet in 1577. Aristotle’s view that the stars and the constellations were forever unchanging still held sway in Tycho’s ...
![Question 6 [11]](http://s1.studyres.com/store/data/002362724_1-d28e5e3b5fe7e9e2fc1d9f01e4127b67-300x300.png)
Question 6 [11]
... There is an interesting relationship between the arrangements of the planets around the sun. The differences in the distances from the sun between subsequent planets show an interesting pattern. This was calculated before Uranus, Neptune and Pluto were discovered and astronomers actually found Uranu ...
... There is an interesting relationship between the arrangements of the planets around the sun. The differences in the distances from the sun between subsequent planets show an interesting pattern. This was calculated before Uranus, Neptune and Pluto were discovered and astronomers actually found Uranu ...
Stellar Evolution
... • As the helium core grows, it compresses. Helium doesn’t fuse to heavier elements for two reasons. (1) with 2 p+ per nucleus, the electric repulsion force is higher than was the case for H-fusion. This means that helium fusion requires a higher temperature than hydrogen fusion -- 100 million K (2) ...
... • As the helium core grows, it compresses. Helium doesn’t fuse to heavier elements for two reasons. (1) with 2 p+ per nucleus, the electric repulsion force is higher than was the case for H-fusion. This means that helium fusion requires a higher temperature than hydrogen fusion -- 100 million K (2) ...
R - AMUSE code
... (which we derived). We know the surface temperature (Teff=5780K) is much smaller than its minimum mean temperature (2×106 K). Thus we make two approximations for the surface boundary conditions: ρM=M, ρ = 0 kg/m3 and T = 0K at r=rs i.e. that the star does have a sharp boundary with the surrounding v ...
... (which we derived). We know the surface temperature (Teff=5780K) is much smaller than its minimum mean temperature (2×106 K). Thus we make two approximations for the surface boundary conditions: ρM=M, ρ = 0 kg/m3 and T = 0K at r=rs i.e. that the star does have a sharp boundary with the surrounding v ...
Powerpoint
... Why is the gas ionized? Remember, takes energetic UV photons to ionize H. Hot, massive stars produce huge amounts of these. Such short-lived stars spend all their lives in the stellar nursery of their birth, so emission nebulae mark sites of ongoing star formation. Many stars of lower mass are form ...
... Why is the gas ionized? Remember, takes energetic UV photons to ionize H. Hot, massive stars produce huge amounts of these. Such short-lived stars spend all their lives in the stellar nursery of their birth, so emission nebulae mark sites of ongoing star formation. Many stars of lower mass are form ...
Power Point Version
... Now it is best to just use the light travel time - 17 years across this box, we say it is 17 light years wide. (This is 2.6X1010 miles across … etc.) ...
... Now it is best to just use the light travel time - 17 years across this box, we say it is 17 light years wide. (This is 2.6X1010 miles across … etc.) ...
The Seven African Powers of Creation
... They are listed in the periodic table of elements that can be found in any chemistry textbook. They start with hydrogen (1 planet), followed by helium (2 planets), all the way to fermium (100 planets, or as they say, 100 electrons). The rest over 100 are artificial elements either man-made, or ephem ...
... They are listed in the periodic table of elements that can be found in any chemistry textbook. They start with hydrogen (1 planet), followed by helium (2 planets), all the way to fermium (100 planets, or as they say, 100 electrons). The rest over 100 are artificial elements either man-made, or ephem ...
Stellar Evolution - Academic Computer Center
... More massive stars are to the upper left, Main Sequence. less massive stars to the lower right. ...
... More massive stars are to the upper left, Main Sequence. less massive stars to the lower right. ...
PH709-10-asn1ans
... Deviations from profile expected from a perfectly opaque disc could provide evidence for satellites, rings. ...
... Deviations from profile expected from a perfectly opaque disc could provide evidence for satellites, rings. ...
OVERVIEW: Stars and space
... Using skills, knowledge and understanding of how science works: • to explain how stars are able to maintain their energy output for millions of years • to explain why the early Universe contained only hydrogen but now contains a large variety of different elements. Skills, knowledge and understandin ...
... Using skills, knowledge and understanding of how science works: • to explain how stars are able to maintain their energy output for millions of years • to explain why the early Universe contained only hydrogen but now contains a large variety of different elements. Skills, knowledge and understandin ...
Astrobiology: young science, old questions
... ribosome formation in extremophiles (and what happens when it goes wrong). Researchers from across science have come together to attempt to uncover the origins of life, and to search for its signature beyond the Earth. The science of astrobiology has come into its prime. One of the beauties of astro ...
... ribosome formation in extremophiles (and what happens when it goes wrong). Researchers from across science have come together to attempt to uncover the origins of life, and to search for its signature beyond the Earth. The science of astrobiology has come into its prime. One of the beauties of astro ...
Chapter 1: Introduction to Earth Science Indiana State Standards 1
... Understand that both weather and climate involve the transfer of matter and energy throughout the atmosphere and hydrosphere, driven by solar energy and gravity. (ES.4.3, ES.4.4, ES.4.5, ES.4.6) SCI.ES.4.1 2010 Examine the origins, structure, composition, and function of Earth’s atmosphere. Include ...
... Understand that both weather and climate involve the transfer of matter and energy throughout the atmosphere and hydrosphere, driven by solar energy and gravity. (ES.4.3, ES.4.4, ES.4.5, ES.4.6) SCI.ES.4.1 2010 Examine the origins, structure, composition, and function of Earth’s atmosphere. Include ...
About Neptune - COSTA VERDE production
... The eighth planet from the Sun, Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky. It is invisible to the naked eye because of its extreme distance from Earth. Interestingly, due to Pluto's unusual elliptical orbit, Neptune is a ...
... The eighth planet from the Sun, Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky. It is invisible to the naked eye because of its extreme distance from Earth. Interestingly, due to Pluto's unusual elliptical orbit, Neptune is a ...
A brightening Sun will boil the seas and bake the continents a billion
... part of the spectrum. Still, the Sun will put out 1,000 times more energy than today. To release this much energy from a cooler surface requires the Sun to swell dramatically. As a red giant, it will appear 100 times bigger than today, taking it beyond Mercury’s orbit and swallowing the innermost pl ...
... part of the spectrum. Still, the Sun will put out 1,000 times more energy than today. To release this much energy from a cooler surface requires the Sun to swell dramatically. As a red giant, it will appear 100 times bigger than today, taking it beyond Mercury’s orbit and swallowing the innermost pl ...
Astronomy 82 - Problem Set #1
... buoyancy and sink back below the photosphere. 3) How long does it take for the sun to convert one Earth mass of hydrogen into helium? First, an initial check: what's a reasonable answer? The sun weighs about 300,000 as much as the earth, so if the time were only “1 hour” then the total lifetime of t ...
... buoyancy and sink back below the photosphere. 3) How long does it take for the sun to convert one Earth mass of hydrogen into helium? First, an initial check: what's a reasonable answer? The sun weighs about 300,000 as much as the earth, so if the time were only “1 hour” then the total lifetime of t ...
Astrobiology - Leiden Observatory
... • But Aristotele had a different idea based on the four elements: earth, fire, water, air • The Earth rested in “the central place” because “fire jut upwards into the sky away from the centre”, and earth fell to the centre • Aristotele discarded the “atomists” around Democritos • Aristotel ...
... • But Aristotele had a different idea based on the four elements: earth, fire, water, air • The Earth rested in “the central place” because “fire jut upwards into the sky away from the centre”, and earth fell to the centre • Aristotele discarded the “atomists” around Democritos • Aristotel ...
History and Philosophy of Western Astronomy
... discovered three laws, based on empirical findings, not on a physical theory. Kepler’s First LawKepler refined Copernicus’ model. He claimed that God uses a different mathematical shape than the circle. Planetary orbits are ellipses with the Sun at one focus. This idea went against the 2,000 year ol ...
... discovered three laws, based on empirical findings, not on a physical theory. Kepler’s First LawKepler refined Copernicus’ model. He claimed that God uses a different mathematical shape than the circle. Planetary orbits are ellipses with the Sun at one focus. This idea went against the 2,000 year ol ...
Compact Objects in the Solar System
... happens the smaller galaxy’s massive center black hole. Hundreds of these could be rogue in the Milky Way– 1000’s to 100,000’s of solar masses! ...
... happens the smaller galaxy’s massive center black hole. Hundreds of these could be rogue in the Milky Way– 1000’s to 100,000’s of solar masses! ...
History of astronomy
... of Roger Bacon (1267): “Greater things than these may be performed by refracted vision. For it is is easy to understand by the canons above mentioned that the greatest things may appear exceeding small, and the contrary. For we can give such figures to transparent bodies, and dispose them in such or ...
... of Roger Bacon (1267): “Greater things than these may be performed by refracted vision. For it is is easy to understand by the canons above mentioned that the greatest things may appear exceeding small, and the contrary. For we can give such figures to transparent bodies, and dispose them in such or ...
Quiz 1 Review
... Type II: high mass star cant fuse iron and outer layers collide with core 23. What do stars between 5-10 solar masses become? Neutron star 24. Explain how a neutron star is formed. After the supernova 20% of the star still remains and this mass still has a huge gravitational force. This gravitationa ...
... Type II: high mass star cant fuse iron and outer layers collide with core 23. What do stars between 5-10 solar masses become? Neutron star 24. Explain how a neutron star is formed. After the supernova 20% of the star still remains and this mass still has a huge gravitational force. This gravitationa ...
PART 1 OBJECTS IN THE SOLAR SYSTEM 4.1 INTRODUCTION
... First proposed by Gerard Kuiper in 1951, many small icy objects, which have also been called “trans-Neptunian” objects and “ice dwarfs,” have now been observed beyond the orbit of Neptune. There are thousands of Kuiper belt objects known to exist including several discovered more recently that rival ...
... First proposed by Gerard Kuiper in 1951, many small icy objects, which have also been called “trans-Neptunian” objects and “ice dwarfs,” have now been observed beyond the orbit of Neptune. There are thousands of Kuiper belt objects known to exist including several discovered more recently that rival ...
Planetary habitability
Planetary habitability is the measure of a planet's or a natural satellite's potential to develop and sustain life. Life may develop directly on a planet or satellite or be transferred to it from another body, a theoretical process known as panspermia. As the existence of life beyond Earth is unknown, planetary habitability is largely an extrapolation of conditions on Earth and the characteristics of the Sun and Solar System which appear favourable to life's flourishing—in particular those factors that have sustained complex, multicellular organisms and not just simpler, unicellular creatures. Research and theory in this regard is a component of planetary science and the emerging discipline of astrobiology.An absolute requirement for life is an energy source, and the notion of planetary habitability implies that many other geophysical, geochemical, and astrophysical criteria must be met before an astronomical body can support life. In its astrobiology roadmap, NASA has defined the principal habitability criteria as ""extended regions of liquid water, conditions favourable for the assembly of complex organic molecules, and energy sources to sustain metabolism.""In determining the habitability potential of a body, studies focus on its bulk composition, orbital properties, atmosphere, and potential chemical interactions. Stellar characteristics of importance include mass and luminosity, stable variability, and high metallicity. Rocky, terrestrial-type planets and moons with the potential for Earth-like chemistry are a primary focus of astrobiological research, although more speculative habitability theories occasionally examine alternative biochemistries and other types of astronomical bodies.The idea that planets beyond Earth might host life is an ancient one, though historically it was framed by philosophy as much as physical science. The late 20th century saw two breakthroughs in the field. The observation and robotic spacecraft exploration of other planets and moons within the Solar System has provided critical information on defining habitability criteria and allowed for substantial geophysical comparisons between the Earth and other bodies. The discovery of extrasolar planets, beginning in the early 1990s and accelerating thereafter, has provided further information for the study of possible extraterrestrial life. These findings confirm that the Sun is not unique among stars in hosting planets and expands the habitability research horizon beyond the Solar System.The chemistry of life may have begun shortly after the Big Bang, 13.8 billion years ago, during a habitable epoch when the Universe was only 10–17 million years old. According to the panspermia hypothesis, microscopic life—distributed by meteoroids, asteroids and other small Solar System bodies—may exist throughout the universe. Nonetheless, Earth is the only place in the universe known to harbor life. Estimates of habitable zones around other stars, along with the discovery of hundreds of extrasolar planets and new insights into the extreme habitats here on Earth, suggest that there may be many more habitable places in the universe than considered possible until very recently. On 4 November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs within the Milky Way. 11 billion of these estimated planets may be orbiting Sun-like stars. The nearest such planet may be 12 light-years away, according to the scientists.