5 - White Dwarfs - University of Texas Astronomy
... then did the white dwarf form in the first place? The separation must have been large so that the progenitor of the white dwarf could form a well-developed core-envelope structure and become a red giant before mass transfer began. If the stars were very close together originally, the big star would ...
... then did the white dwarf form in the first place? The separation must have been large so that the progenitor of the white dwarf could form a well-developed core-envelope structure and become a red giant before mass transfer began. If the stars were very close together originally, the big star would ...
Changes in a scientific concept: what is a planet? - Philsci
... historically incorrect. In the history of astronomy there is no reference to the roundness of a body as a condition for its status as a planet. For example, Ceres was initially considered a planet, and later demoted from planet, but its shape was unknown. The fourth criterion is orbital dominance. ...
... historically incorrect. In the history of astronomy there is no reference to the roundness of a body as a condition for its status as a planet. For example, Ceres was initially considered a planet, and later demoted from planet, but its shape was unknown. The fourth criterion is orbital dominance. ...
Level 2 Meteorites, Shooting Stars, and Comets
... chunks of rock. Therefore we get many more meteors at these times. More precisely, meteor showers happen when Earth, on its way around the Sun, passes through the path of a comet. That's because as a comet orbits near the Sun, it starts to melt down and ejects on its path lots of dust and chunks of ...
... chunks of rock. Therefore we get many more meteors at these times. More precisely, meteor showers happen when Earth, on its way around the Sun, passes through the path of a comet. That's because as a comet orbits near the Sun, it starts to melt down and ejects on its path lots of dust and chunks of ...
Variability of solar/stellar activity and magnetic field and its influence... planetary atmosphere evolution
... The much stronger magnetic activity of the young Sun resulted in increased flaring activity, CMEs and denser and more energetic solar wind and particle fluxes. For the study of atmospheric evolution and related thermal and nonthermal escape processes the evolution of the X-ray, SXR and EUV flux is o ...
... The much stronger magnetic activity of the young Sun resulted in increased flaring activity, CMEs and denser and more energetic solar wind and particle fluxes. For the study of atmospheric evolution and related thermal and nonthermal escape processes the evolution of the X-ray, SXR and EUV flux is o ...
New Light on the Solar System
... ethereal rings around the gas giants. Jupiter’s satellite Europa has icy niches where life might evolve. (As this issue goes to press, astronomers are remarking that as Pluto’s orbit carries it farther from the sun, the planet’s atmosphere is curiously warming up.) Though astronomers have begun to d ...
... ethereal rings around the gas giants. Jupiter’s satellite Europa has icy niches where life might evolve. (As this issue goes to press, astronomers are remarking that as Pluto’s orbit carries it farther from the sun, the planet’s atmosphere is curiously warming up.) Though astronomers have begun to d ...
with answers
... From v) we find that it will take 9.81 billion years for the hydrogen to be depleted, however, we are told that the Sun will only have 5 billion years of active life left (Shröder & Connon Smith 2008). This is a large discrepancy (almost twice as long). Possible reasons for the discrepancy: ● not al ...
... From v) we find that it will take 9.81 billion years for the hydrogen to be depleted, however, we are told that the Sun will only have 5 billion years of active life left (Shröder & Connon Smith 2008). This is a large discrepancy (almost twice as long). Possible reasons for the discrepancy: ● not al ...
Possibility of explosion of a giant planet.
... the Soviet Union and the United States in the late 1940's this design abandoned in favor of the scheme with the implosion compression of the tube casing by radiation. So is the situation based on declassified sources. But we cannot be sure that all information on this sensitive issue is declassified ...
... the Soviet Union and the United States in the late 1940's this design abandoned in favor of the scheme with the implosion compression of the tube casing by radiation. So is the situation based on declassified sources. But we cannot be sure that all information on this sensitive issue is declassified ...
Pathways to Astronomy/Space
... types of students that are in your class, and plan with their abilities in mind. It may be more appropriate for you to select the lens we have designated as applied for your class, or it may be more appropriate for you to select the lens that can be modified to suit both needs. Or you may wish to ch ...
... types of students that are in your class, and plan with their abilities in mind. It may be more appropriate for you to select the lens we have designated as applied for your class, or it may be more appropriate for you to select the lens that can be modified to suit both needs. Or you may wish to ch ...
silicon and oxygen abundances in planet-host stars
... planets. Since giant planet cores are thought to grow from silicate grains with icy mantles, the likelihood of gas giant formation should depend heavily on the oxygen and silicon abundance of the planet formation environment. Here we compare the silicon and oxygen abundances of a set of 76 planet ho ...
... planets. Since giant planet cores are thought to grow from silicate grains with icy mantles, the likelihood of gas giant formation should depend heavily on the oxygen and silicon abundance of the planet formation environment. Here we compare the silicon and oxygen abundances of a set of 76 planet ho ...
death_high_mass
... hydrogen that is introduced into the area around the core where temperatures and pressures are high enough for hydrogen fusion to take place. • Hydrogen begins to fuse into helium, in a shell around the shrinking helium core. • Now there are two energy sources in the star. ...
... hydrogen that is introduced into the area around the core where temperatures and pressures are high enough for hydrogen fusion to take place. • Hydrogen begins to fuse into helium, in a shell around the shrinking helium core. • Now there are two energy sources in the star. ...
teach with space
... exert the same gravitational force of attraction on each other, and both of their trajectories will be affected by this gravitational force. This means that if we are considering a system of two bodies, for example the Earth and the Moon, it is not the Moon that orbits the Earth – both the Earth and ...
... exert the same gravitational force of attraction on each other, and both of their trajectories will be affected by this gravitational force. This means that if we are considering a system of two bodies, for example the Earth and the Moon, it is not the Moon that orbits the Earth – both the Earth and ...
Surveying the Stars
... A star’s full classification includes spectral type (based on spectral line identities) and luminosity class (based on spectral line shapes, which are related to the size of the star) ...
... A star’s full classification includes spectral type (based on spectral line identities) and luminosity class (based on spectral line shapes, which are related to the size of the star) ...
The complex planetary synchronization structure of the solar system
... Following the discovery of Ceres in 1801, numerous asteroids were discovered at approximately the same orbital distance. The region in which these asteroids were found lies between Mars and Jupiter and it is known as the Asteroid Belt. No planet could form in this region because of the gravitational ...
... Following the discovery of Ceres in 1801, numerous asteroids were discovered at approximately the same orbital distance. The region in which these asteroids were found lies between Mars and Jupiter and it is known as the Asteroid Belt. No planet could form in this region because of the gravitational ...
3. What are the intrinsic and extrinsic environments of exoplanets?
... carefully vetted information on both the stars themselves and their immediate environments. The compilation will focus on the nearest stars, but will include all known exoplanetary systems, including new results from ground and space based observations (e.g., microlensing surveys, high precision sp ...
... carefully vetted information on both the stars themselves and their immediate environments. The compilation will focus on the nearest stars, but will include all known exoplanetary systems, including new results from ground and space based observations (e.g., microlensing surveys, high precision sp ...
Life on Other Worlds
... may throw them away upon such subjects as this; but I suppose they who can spend their time better, will not be at so vain and fruitless an expence." (John Glanvill's translation of 1688.) The question whether life exists on other worlds is one that still excites curiosity, and to which astronomers ...
... may throw them away upon such subjects as this; but I suppose they who can spend their time better, will not be at so vain and fruitless an expence." (John Glanvill's translation of 1688.) The question whether life exists on other worlds is one that still excites curiosity, and to which astronomers ...
The University of Sydney Page
... Very low mass stars Very low mass stars (mass less than about 0.4 solar masses) are different in one important respect from heavier stars: their interiors are fully convective. The fused helium is stirred through the whole star, so it has the whole of its hydrogen mass to prolong its stay on the ma ...
... Very low mass stars Very low mass stars (mass less than about 0.4 solar masses) are different in one important respect from heavier stars: their interiors are fully convective. The fused helium is stirred through the whole star, so it has the whole of its hydrogen mass to prolong its stay on the ma ...
Calculate the Mass of the Milky Way Galaxy
... • During the uncertainties of the era, Hubble was able to observe galaxies at distances up to 7 million light years away. By doing so he was able to come up with Hubble's Law, which said that the further galaxies were away from earth the faster they moved away from our planet. Hubble's rule proved t ...
... • During the uncertainties of the era, Hubble was able to observe galaxies at distances up to 7 million light years away. By doing so he was able to come up with Hubble's Law, which said that the further galaxies were away from earth the faster they moved away from our planet. Hubble's rule proved t ...
Stellar Physics
... black of night. You see a single light which may be a motorcycle. How do you know how far way it is? (Is it a motorcycle or something else?) Practical demonstration: various small light sources of varying brightnesses could be placed in a totally darkened room or corridor. Four would be a suitable n ...
... black of night. You see a single light which may be a motorcycle. How do you know how far way it is? (Is it a motorcycle or something else?) Practical demonstration: various small light sources of varying brightnesses could be placed in a totally darkened room or corridor. Four would be a suitable n ...
Chapter 18 - Origin and Evolution of Stars Chapter Preview
... Open clusters are small and irregularly shaped, typically containing 1000 members. They have a large range of ages from very young to 10 billion years old. The color of an open cluster as a whole ranges from blue to red, and as we will see, this depends on the cluster’s age. Open clusters are loosel ...
... Open clusters are small and irregularly shaped, typically containing 1000 members. They have a large range of ages from very young to 10 billion years old. The color of an open cluster as a whole ranges from blue to red, and as we will see, this depends on the cluster’s age. Open clusters are loosel ...
The Copernican revolution - University of Florida Astronomy
... 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 the Sun; it is the center of the universe. With rare exceptions such as Aristarchus (310-230 B.C.), the Greeks rejected the correct explanation (1) because ...
... 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 the Sun; it is the center of the universe. With rare exceptions such as Aristarchus (310-230 B.C.), the Greeks rejected the correct explanation (1) because ...
Impact of atmospheric refraction: How deeply can we probe exo
... The third effect, illustrated in Figure 2 for the cylindrically symmetric case when the planet occults the central region of its star, is a purely geometrical effect linked to the angular size of the host star with respect to the planet, and has only been included in a few papers (Garcı́a Muñoz & M ...
... The third effect, illustrated in Figure 2 for the cylindrically symmetric case when the planet occults the central region of its star, is a purely geometrical effect linked to the angular size of the host star with respect to the planet, and has only been included in a few papers (Garcı́a Muñoz & M ...
Word Document - Montana State University
... (negative) or away (positive) from the observer’s line of sight is known as the radial velocity. The component of velocity that is directed perpendicular to the observer’s line of sight is known as the tangential velocity. Imagine that you are the observer shown in each of the drawings. i. At which ...
... (negative) or away (positive) from the observer’s line of sight is known as the radial velocity. The component of velocity that is directed perpendicular to the observer’s line of sight is known as the tangential velocity. Imagine that you are the observer shown in each of the drawings. i. At which ...
The Origin, Structure, and Evolution of the Stars
... this material accounts for about one tenth the mass of the galaxy quite enough to provide material for the formation of new stars astronomers believe that initially the galaxy was an ellipsoid of gas that tended to flatten to its present form because of its rotation the physical processes by which t ...
... this material accounts for about one tenth the mass of the galaxy quite enough to provide material for the formation of new stars astronomers believe that initially the galaxy was an ellipsoid of gas that tended to flatten to its present form because of its rotation the physical processes by which t ...
ABSOLUTE AND APPARENT MAGNITUDES
... At magnitude -19.36, Sol would still look brighter than the full moon seen from Earth as seen from Neptune. It would obviously cast shadows, and would scatter light in Neptune’s cloudtops so that the sky would probably be a deep blue as seen by a viewer sitting in the planet’s upper atmosphere. Next ...
... At magnitude -19.36, Sol would still look brighter than the full moon seen from Earth as seen from Neptune. It would obviously cast shadows, and would scatter light in Neptune’s cloudtops so that the sky would probably be a deep blue as seen by a viewer sitting in the planet’s upper atmosphere. Next ...
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.