Sample final exam
... that line of thought – assume you are made out of nothing but carbon, hydrogen oxygen, nitrogen, sulfur (S) and phosphorus (P). Where was the ultimate origin of all of the atoms of these elements that are now in your body? Caution: they may have separate origins! ...
... that line of thought – assume you are made out of nothing but carbon, hydrogen oxygen, nitrogen, sulfur (S) and phosphorus (P). Where was the ultimate origin of all of the atoms of these elements that are now in your body? Caution: they may have separate origins! ...
Stars: Binary Systems
... Getting the separation, a Although we can measure the period, P, directly, we need to know the distance to get the separation, a. Recall that, d(pc) = 1/P, where P is in arc seconds, which is based on the definition that 1 arc sec is the angular separation of the Earth-Sun system (1 AU ) at a dista ...
... Getting the separation, a Although we can measure the period, P, directly, we need to know the distance to get the separation, a. Recall that, d(pc) = 1/P, where P is in arc seconds, which is based on the definition that 1 arc sec is the angular separation of the Earth-Sun system (1 AU ) at a dista ...
File
... The Ant Nebula, a cloud of dust and gas whose technical name is Mz3, resembles an ant when observed using ground-based telescopes. The nebula lies within our galaxy between 3,000 and 6,000 light years from Earth . ...
... The Ant Nebula, a cloud of dust and gas whose technical name is Mz3, resembles an ant when observed using ground-based telescopes. The nebula lies within our galaxy between 3,000 and 6,000 light years from Earth . ...
Lecture 31: The Properties of Stars
... This lecture describes the basic observed properties of stars. The color of a star depends on its temperature: cooler stars are redder, hotter stars are blue. Luminosity, the total energy output expressed in Watts or Solar Luminosities, depends on the radius and temperature. The absorption spectra o ...
... This lecture describes the basic observed properties of stars. The color of a star depends on its temperature: cooler stars are redder, hotter stars are blue. Luminosity, the total energy output expressed in Watts or Solar Luminosities, depends on the radius and temperature. The absorption spectra o ...
Measuring Stellar Distances
... moment – suppose you had no prior knowledge of what stars actually were – that you lived in a time where they could be anything. If you simply look up into the night sky you have no idea how far away these objects are or whether or not they are part of our atmosphere, in our solar system, or located ...
... moment – suppose you had no prior knowledge of what stars actually were – that you lived in a time where they could be anything. If you simply look up into the night sky you have no idea how far away these objects are or whether or not they are part of our atmosphere, in our solar system, or located ...
Star Types - University of Massachusetts Amherst
... the magnitude you would observe, were the source placed at 10 pc m – M = -5 + 5 x Log (d) ...
... the magnitude you would observe, were the source placed at 10 pc m – M = -5 + 5 x Log (d) ...
The correct answers are written in bold, italic and underlined. The
... • the core of a red giant star, revealed when the outer layers are shed during the planetary nebula phase. • a white dwarf star that has cooled to a low temperature over its long lifetime. Stars with masses less that 8% of that of the Sun remain as long-lived, dim brown objects, never brightening li ...
... • the core of a red giant star, revealed when the outer layers are shed during the planetary nebula phase. • a white dwarf star that has cooled to a low temperature over its long lifetime. Stars with masses less that 8% of that of the Sun remain as long-lived, dim brown objects, never brightening li ...
Star in a Box
... But eventually it will swell into a giant star, becoming more luminous but cooler. ...
... But eventually it will swell into a giant star, becoming more luminous but cooler. ...
Distant Stars Lesson Plan
... Watch the “Distant Stars” segment of the “How far away is it” video book Optionally, find Ch Cygni on the Chandra Space Observatory website. Calculate a star’s luminosity using the H-R Diagram Take a short quiz ...
... Watch the “Distant Stars” segment of the “How far away is it” video book Optionally, find Ch Cygni on the Chandra Space Observatory website. Calculate a star’s luminosity using the H-R Diagram Take a short quiz ...
Stellar Evolution
... • Think back to the first carbon core. • How they get from main sequence to the carbon core stage is a little different. • Now however, there is enough mass that it becomes hot enough to ...
... • Think back to the first carbon core. • How they get from main sequence to the carbon core stage is a little different. • Now however, there is enough mass that it becomes hot enough to ...
slides
... The distance from Earth of the red supergiant Betelgeuse is approximately 643 light-years. If it were to explode as a supernova, it would be one of the brightest stars in the sky. Right now, the brightest star other than the Sun is Sirius, with a luminosity of 26LSun and a distance of 8.6 light-year ...
... The distance from Earth of the red supergiant Betelgeuse is approximately 643 light-years. If it were to explode as a supernova, it would be one of the brightest stars in the sky. Right now, the brightest star other than the Sun is Sirius, with a luminosity of 26LSun and a distance of 8.6 light-year ...
earth & space science
... A star enters its third stage when almost all of the hydrogen atoms within its core have fused into helium atoms. A star’s shell of gases grows cooler as it expands. As the gases in the outer shell become cooler, they begin to glow with a reddish color. These stars are known as giants. ...
... A star enters its third stage when almost all of the hydrogen atoms within its core have fused into helium atoms. A star’s shell of gases grows cooler as it expands. As the gases in the outer shell become cooler, they begin to glow with a reddish color. These stars are known as giants. ...
Problem Set No. 5
... sun only burns a fraction (about 10%) of its hydrogen before leaving the main sequence. While a 0.4 M⊙ star may burn a larger fraction of its hydrogen, we do not think it would burn it all before leaving the main sequence. If, however, it were fully mixed, it would burn all its hydrogen and could th ...
... sun only burns a fraction (about 10%) of its hydrogen before leaving the main sequence. While a 0.4 M⊙ star may burn a larger fraction of its hydrogen, we do not think it would burn it all before leaving the main sequence. If, however, it were fully mixed, it would burn all its hydrogen and could th ...
Due: January 14, 2014 Name: White dwarfs are “has been
... The energy radiated from a protostar comes from gravitational potential energy that is converted to kinetic and then thermal energy when the matter within the protostar falls toward the core. The energy radiated by a main-sequence star comes from nuclear fusion. ...
... The energy radiated from a protostar comes from gravitational potential energy that is converted to kinetic and then thermal energy when the matter within the protostar falls toward the core. The energy radiated by a main-sequence star comes from nuclear fusion. ...
Star Formation: Interstellar Gas and Dust
... Very massive stars also expel material late in life ...
... Very massive stars also expel material late in life ...
Evolution of low
... Evolution of 4Mo Stars • For stars less than 6Mo these last slides describe the evolution pretty well. There are some differences in the details that depend on the initial main-sequence mass. • For stars that start with 4Mo, it gets hot enough in the cores to (1) avoid the helium flash and (2) to ...
... Evolution of 4Mo Stars • For stars less than 6Mo these last slides describe the evolution pretty well. There are some differences in the details that depend on the initial main-sequence mass. • For stars that start with 4Mo, it gets hot enough in the cores to (1) avoid the helium flash and (2) to ...
Lecture 5: The H-R diagram, standard candles and cosmic distances
... • Some binaries can be detected and analysed, even though the two star images cannot be resolved • A spectrum binary appears to be a single star but has a spectrum with the absorption lines for two distinctly different spectral types • A spectroscopic binary has spectral lines that shift back and ...
... • Some binaries can be detected and analysed, even though the two star images cannot be resolved • A spectrum binary appears to be a single star but has a spectrum with the absorption lines for two distinctly different spectral types • A spectroscopic binary has spectral lines that shift back and ...
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.