SECTION 30.2 Measuring the Stars 1. Constellations are a. the
... a. the brightest stars. b. stars over Greece. c. groups of stars named after animals, mythological characters, or everyday objects. d. found only in the northern hemisphere. 2. Ursa Major, or the big dipper, is an example of a a. circumpolar constellation. b. constellation that can be seen only in w ...
... a. the brightest stars. b. stars over Greece. c. groups of stars named after animals, mythological characters, or everyday objects. d. found only in the northern hemisphere. 2. Ursa Major, or the big dipper, is an example of a a. circumpolar constellation. b. constellation that can be seen only in w ...
A-36_SF
... Summary II • Stars pass through several stages as they form – Molecular clouds are in equilibrium until collapse – Protostars shine by gravity as they contract – Disks form through conservation of angular momentum • Their properties tell us about planet formation process • Inner holes and clumps pr ...
... Summary II • Stars pass through several stages as they form – Molecular clouds are in equilibrium until collapse – Protostars shine by gravity as they contract – Disks form through conservation of angular momentum • Their properties tell us about planet formation process • Inner holes and clumps pr ...
Stars and Galaxies part 3
... 400 light-years away, and is most accurate for close stars. • FYI: Hipparcos was a satellite that operated between 1989 and 1993. Its purpose was the accurate measurement of the positions of celestial objects. This permitted the relatively accurate determination of distance to stars up to 400 light ...
... 400 light-years away, and is most accurate for close stars. • FYI: Hipparcos was a satellite that operated between 1989 and 1993. Its purpose was the accurate measurement of the positions of celestial objects. This permitted the relatively accurate determination of distance to stars up to 400 light ...
Document
... • T Tauri stars represent an intermediate stage between protostars and low-mass main sequence (hydrogen burning) stars like the Sun. • Protostars forms from molecular clouds. When a portion of a molecular cloud reaches a critical mass it begins to collapse under its own gravity. The initial collapse ...
... • T Tauri stars represent an intermediate stage between protostars and low-mass main sequence (hydrogen burning) stars like the Sun. • Protostars forms from molecular clouds. When a portion of a molecular cloud reaches a critical mass it begins to collapse under its own gravity. The initial collapse ...
Slide 1 - Physics @ IUPUI
... • RR Lyrae – lower mass stars after they undergo their Helium flash (the sun will do this someday). • RR Lyrae are Horizontal Branch stars. • Metal rich and Metal poor Cepheid variables (Type I and II). • These are the higher mass stars which pass back and forth through the instability strip. ...
... • RR Lyrae – lower mass stars after they undergo their Helium flash (the sun will do this someday). • RR Lyrae are Horizontal Branch stars. • Metal rich and Metal poor Cepheid variables (Type I and II). • These are the higher mass stars which pass back and forth through the instability strip. ...
The Death of a Low Mass Star
... – In consequence, molecular absorption bands often seen in the spectra of AGB stars – Soot coccoons may also form around such ...
... – In consequence, molecular absorption bands often seen in the spectra of AGB stars – Soot coccoons may also form around such ...
Lecture 22 - Seattle Central
... Solid isn’t so solid (the nucleus is 106x too large in that pic): ...
... Solid isn’t so solid (the nucleus is 106x too large in that pic): ...
HERE
... As a star runs out of hydrogen to fuse, its core collapses and sends a shock wave from the heat outward, expanding the outer layers of the star. The temperature and pressure conditions in the core increase enough to induce the fusion of heavier elements late in its life. Betelgeuse, pictured at left ...
... As a star runs out of hydrogen to fuse, its core collapses and sends a shock wave from the heat outward, expanding the outer layers of the star. The temperature and pressure conditions in the core increase enough to induce the fusion of heavier elements late in its life. Betelgeuse, pictured at left ...
AST 301 Introduction to Astronomy - University of Texas Astronomy
... Becoming a Red Giant (The complete explanation for how a main-sequence star becomes a red giant is complicated, and I’m not really giving you the whole story. But the conclusion is right. Don’t worry if you don’t follow all of the explanation.) When all of the hydrogen in the core of a main-sequenc ...
... Becoming a Red Giant (The complete explanation for how a main-sequence star becomes a red giant is complicated, and I’m not really giving you the whole story. But the conclusion is right. Don’t worry if you don’t follow all of the explanation.) When all of the hydrogen in the core of a main-sequenc ...
The Hertzsprung-Russell Diagram
... About half the stars in the sky have stellar companions, bound together by gravity and in orbit around each other. Some of these can be seen by the eye or in a telescope, others are too close to be resolved. You can see stars together, but they must also share a common motion and be at the same dis ...
... About half the stars in the sky have stellar companions, bound together by gravity and in orbit around each other. Some of these can be seen by the eye or in a telescope, others are too close to be resolved. You can see stars together, but they must also share a common motion and be at the same dis ...
Lesson 4, Stars
... Compare the development of a less-massive star with that of a more-massive star. A less-massive star: begins as a nebula, becomes a protostar, a main-sequence star, a red giant, and finally, a white dwarf. A more-massive star: begins as a nebula, becomes a protostar, a main-sequence star, a ve ...
... Compare the development of a less-massive star with that of a more-massive star. A less-massive star: begins as a nebula, becomes a protostar, a main-sequence star, a red giant, and finally, a white dwarf. A more-massive star: begins as a nebula, becomes a protostar, a main-sequence star, a ve ...
6. 1 Star Distances 6. 2 Apparent Brightness, Intrinsic Brightness
... important graph in astronomy becau se it sorts the stars into categories by size. Roughly 90 percent of normal stars, including the sun, fall on the main sequence, with the hotter main-sequence stars being more luminous. The giants and supergiants, however, are much larger and lie above the main seq ...
... important graph in astronomy becau se it sorts the stars into categories by size. Roughly 90 percent of normal stars, including the sun, fall on the main sequence, with the hotter main-sequence stars being more luminous. The giants and supergiants, however, are much larger and lie above the main seq ...
Word doc - UC-HiPACC - University of California, Santa Cruz
... Stars are born in groups or clusters when a cold giant molecular cloud collapses under its own gravitational force. If many stars form all at once—that is, if star formation efficiency is high—they will stay together as a gravitationally bound open cluster (like the Pleiades) or a globular cluster ( ...
... Stars are born in groups or clusters when a cold giant molecular cloud collapses under its own gravitational force. If many stars form all at once—that is, if star formation efficiency is high—they will stay together as a gravitationally bound open cluster (like the Pleiades) or a globular cluster ( ...
d = 1 / p
... if we know the total power emitted by a star (its luminosity), and we know its temperature from Wien's law, we can calculate its total surface area – and determine its size. To do this in practice, first find the energy per second emitted by each unit of surface area, ε, using the relation given in ...
... if we know the total power emitted by a star (its luminosity), and we know its temperature from Wien's law, we can calculate its total surface area – and determine its size. To do this in practice, first find the energy per second emitted by each unit of surface area, ε, using the relation given in ...
d = 1 / p
... A quick glance at the night sky will tell you that different stars have different brightnesses. But how much of that effect is due to the fact that some stars are further away, and how much is due to certain stars being intrinsically brighter? If we know the distances from parallax, we can remove th ...
... A quick glance at the night sky will tell you that different stars have different brightnesses. But how much of that effect is due to the fact that some stars are further away, and how much is due to certain stars being intrinsically brighter? If we know the distances from parallax, we can remove th ...
8.1 Stars
... neutrons only about 15 km across, it is called a neutron star. Neutron stars are made of the densest material known ...
... neutrons only about 15 km across, it is called a neutron star. Neutron stars are made of the densest material known ...
Stars
... • Objects that heat and light the planets in a system • A ball of plasma held together by its own gravity – Nuclear reactions (fusion) occur in stars (H He) – Energy from the nuclear reactions is released as electromagnetic radiation ...
... • Objects that heat and light the planets in a system • A ball of plasma held together by its own gravity – Nuclear reactions (fusion) occur in stars (H He) – Energy from the nuclear reactions is released as electromagnetic radiation ...
The Life Cycle of a Star and the Hertzsprung
... tells us two things about each star: its luminosity (brightness) and its temperature. The majority of stars, including our Sun, are found along a region called the Main Sequence. Main Sequence stars vary widely in effective temperature but the hotter they are, the more luminous (brighter) they are, ...
... tells us two things about each star: its luminosity (brightness) and its temperature. The majority of stars, including our Sun, are found along a region called the Main Sequence. Main Sequence stars vary widely in effective temperature but the hotter they are, the more luminous (brighter) they are, ...
MSci Astrophysics 210PHY412 - Queen's University Belfast
... The existence of a superwind is suggested by two independent variables. The high density observed within the observed shells in stellar ejecta, and relative paucity of very bright stars on the AGB. The latter (Prialnik P. 161) comes from the number of AGB stars expected compared to observed is >10. ...
... The existence of a superwind is suggested by two independent variables. The high density observed within the observed shells in stellar ejecta, and relative paucity of very bright stars on the AGB. The latter (Prialnik P. 161) comes from the number of AGB stars expected compared to observed is >10. ...
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.