Dyson Spheres around White Dwarfs arXiv:1503.04376
... A Dyson Sphere represents a particular realization of the Kardashev Type II stage, the obvious way to ”catch” all the power of a star. Dyson [1] in the original paper2 points out that such a sphere would have to emit thermal radiation with total power3 equal to that of the star. Since it would look ...
... A Dyson Sphere represents a particular realization of the Kardashev Type II stage, the obvious way to ”catch” all the power of a star. Dyson [1] in the original paper2 points out that such a sphere would have to emit thermal radiation with total power3 equal to that of the star. Since it would look ...
spectral lines as distant measurement tools
... and white dwarfs. The star-by-star point density in this HRD corresponds to stellar statistics: there are far more dwarfs than giants — but it is likely that many more white dwarfs exist than we observe. The multiple locations per column imply that another parameter than only the spectral type is ne ...
... and white dwarfs. The star-by-star point density in this HRD corresponds to stellar statistics: there are far more dwarfs than giants — but it is likely that many more white dwarfs exist than we observe. The multiple locations per column imply that another parameter than only the spectral type is ne ...
Lecture 12: Evolution of the Galaxy
... • New stars which form therefore have higher values of heavy element mass fraction, Z, at the time of their birth. The youngest stars are therefore the most heavy-element rich, and the oldest ones (Population II stars) are the most deficient in heavy elements relative to the Sun. • Halo Population I ...
... • New stars which form therefore have higher values of heavy element mass fraction, Z, at the time of their birth. The youngest stars are therefore the most heavy-element rich, and the oldest ones (Population II stars) are the most deficient in heavy elements relative to the Sun. • Halo Population I ...
Comparison of low- and high-mass star formation
... McKee–Tan core (McKee & Tan 2003). However, the “cores” so identified are transient objects that are not in equilibrium. They are evolving constantly, with mass growing (from converging or collapsing flow) and depleting (into one or more collapsed objects) at the same time. The replenishment of dens ...
... McKee–Tan core (McKee & Tan 2003). However, the “cores” so identified are transient objects that are not in equilibrium. They are evolving constantly, with mass growing (from converging or collapsing flow) and depleting (into one or more collapsed objects) at the same time. The replenishment of dens ...
Introduction
... present in different forms. Some of these forms are listed in Table 1.1. Not all of these components are found in every galaxy. In some galaxies, for example, star formation ended long ago, and no new stars have been born for many billions of years; in such galaxies the upper end of the main sequenc ...
... present in different forms. Some of these forms are listed in Table 1.1. Not all of these components are found in every galaxy. In some galaxies, for example, star formation ended long ago, and no new stars have been born for many billions of years; in such galaxies the upper end of the main sequenc ...
Hubble Space Telescope Image
... distorting light from individual members of this cluster so that we see a halo effect. distant galaxies, which lie five to 10 times farther than Abell 2218. This distant population existed when the universe was just a quarter of its current age. ...
... distorting light from individual members of this cluster so that we see a halo effect. distant galaxies, which lie five to 10 times farther than Abell 2218. This distant population existed when the universe was just a quarter of its current age. ...
An introduce of the spectrograph of the GALEX
... functions of red and blue galaxies to z~1. (...) After z~1, M*B has dimmed by 1.2-1.3 mag for all colors of galaxies, φ* for blue galaxies has hardly changed, and φ* for red galaxies has at least doubled (our formal value is ~0.5 dex). Luminosity density jB has fallen by 0.6 dex for blue galaxies bu ...
... functions of red and blue galaxies to z~1. (...) After z~1, M*B has dimmed by 1.2-1.3 mag for all colors of galaxies, φ* for blue galaxies has hardly changed, and φ* for red galaxies has at least doubled (our formal value is ~0.5 dex). Luminosity density jB has fallen by 0.6 dex for blue galaxies bu ...
Chapter 2
... higher latitudes, the north celestial pole climbs higher in the sky. As this happens, the circumpolar region grows in size. On reaching the terrestrial pole, you would see the north celestial pole directly overhead. Both your latitude and the altitude of the north celestial pole would be 90⬚. The ce ...
... higher latitudes, the north celestial pole climbs higher in the sky. As this happens, the circumpolar region grows in size. On reaching the terrestrial pole, you would see the north celestial pole directly overhead. Both your latitude and the altitude of the north celestial pole would be 90⬚. The ce ...
From Dust to Planets - International Space Science Institute
... years later, over 50 such giant planets have been found (Figure 1). implying that at least 3–5% of all sun-like stars have giant planets. Since this represents only the fraction of stars having planets that could be detected with current instruments, we must conclude that planet formation is not an ...
... years later, over 50 such giant planets have been found (Figure 1). implying that at least 3–5% of all sun-like stars have giant planets. Since this represents only the fraction of stars having planets that could be detected with current instruments, we must conclude that planet formation is not an ...
12. Stars
... • Some stars vary in brightness because they cannot achieve proper balance between power welling up from the core and power radiated from the surface. • Such a star alternately expands and contracts, varying in brightness as it tries to find a balance. © 2010 Pearson Education, Inc. ...
... • Some stars vary in brightness because they cannot achieve proper balance between power welling up from the core and power radiated from the surface. • Such a star alternately expands and contracts, varying in brightness as it tries to find a balance. © 2010 Pearson Education, Inc. ...
6.1 Introduction
... in the gas from which stars have recently formed, such as the Orion nebula. Possibly these most metal-poor stars have been enriched by only one previous generation of stars which themselves presumably formed out of pristine gas. Thus, the chemical composition of the most metal-poor stars known is on ...
... in the gas from which stars have recently formed, such as the Orion nebula. Possibly these most metal-poor stars have been enriched by only one previous generation of stars which themselves presumably formed out of pristine gas. Thus, the chemical composition of the most metal-poor stars known is on ...
Seeds of a Tychonic Revolution: Telescopic Observations of the
... have disks that are less than half the size of the brightest stars, and so must be more than twice as far away. In fact, the faintest stars visible to the naked eye, whose diameters, as seen through Mareo's telescope, are an arcsecond or less, must be two thousand or more AU distant. Very faint star ...
... have disks that are less than half the size of the brightest stars, and so must be more than twice as far away. In fact, the faintest stars visible to the naked eye, whose diameters, as seen through Mareo's telescope, are an arcsecond or less, must be two thousand or more AU distant. Very faint star ...
Search For Dark Matters Essay Research Paper
... our telescopes.) The most obvious example of the gravitational effects of dark matter can be observed when looking at the rotation of galaxies. To study galactic rotation, astronomers look at the emission line spectra of stars in each part of the galaxy. When the light from a star is observed using ...
... our telescopes.) The most obvious example of the gravitational effects of dark matter can be observed when looking at the rotation of galaxies. To study galactic rotation, astronomers look at the emission line spectra of stars in each part of the galaxy. When the light from a star is observed using ...
Chapter 8 Pre-galactic enrichment of the IGM 8.1 Summary
... entire volume of gas polluted by metals) increases in VFF to 0.048 for both Case A and 0.046 for Case B. This corresponds to 28% (26%) of the baryon mass being enriched for Case A (Case B). The two cases are essentially indistinguishable with regards to the total mass and volume of gas polluted by m ...
... entire volume of gas polluted by metals) increases in VFF to 0.048 for both Case A and 0.046 for Case B. This corresponds to 28% (26%) of the baryon mass being enriched for Case A (Case B). The two cases are essentially indistinguishable with regards to the total mass and volume of gas polluted by m ...
As far as - Sangeeta Malhotra
... HUDF distance scale starts within our own galaxy. The closest object we have identified, an M-type dwarf star we designated Ultra Deep Field (UDF) 366, lies 2,000 light-years away, still in our galaxy’s disk. Most of the stars we detected are lowmass M dwarfs, which are both faint and numerous. We c ...
... HUDF distance scale starts within our own galaxy. The closest object we have identified, an M-type dwarf star we designated Ultra Deep Field (UDF) 366, lies 2,000 light-years away, still in our galaxy’s disk. Most of the stars we detected are lowmass M dwarfs, which are both faint and numerous. We c ...
Distance determination for RAVE stars using stellar models
... spirals, and finally dwarf galaxies. The power spectrum is used to measure the power of density perturbations on a certain scale. The current cosmological model predicts a HarrisonZel’dovich spectrum (P (k) ∝ k, where k is the wavenumber). This power spectrum predicts more power on small scale, so t ...
... spirals, and finally dwarf galaxies. The power spectrum is used to measure the power of density perturbations on a certain scale. The current cosmological model predicts a HarrisonZel’dovich spectrum (P (k) ∝ k, where k is the wavenumber). This power spectrum predicts more power on small scale, so t ...
DTU_9e_ch15
... Young OB associations, H II regions, and molecular clouds in the galactic disk outline huge spiral arms where stars are forming. The Sun is located about 26,000 ly from the galactic nucleus, between the spiral arms. The Sun moves in its orbit at a speed of about 878,000 km/h and takes about 230 mill ...
... Young OB associations, H II regions, and molecular clouds in the galactic disk outline huge spiral arms where stars are forming. The Sun is located about 26,000 ly from the galactic nucleus, between the spiral arms. The Sun moves in its orbit at a speed of about 878,000 km/h and takes about 230 mill ...
Ursa Minor
Ursa Minor (Latin: ""Smaller She-Bear"", contrasting with Ursa Major), also known as the Little Bear, is a constellation in the northern sky. Like the Great Bear, the tail of the Little Bear may also be seen as the handle of a ladle, hence the name Little Dipper. It was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and remains one of the 88 modern constellations. Ursa Minor has traditionally been important for navigation, particularly by mariners, due to Polaris being the North Star.Polaris, the brightest star in the constellation, is a yellow-white supergiant and the brightest Cepheid variable star in the night sky, ranging from apparent magnitude 1.97 to 2.00. Beta Ursae Minoris, also known as Kochab, is an aging star that has swollen and cooled to become an orange giant with an apparent magnitude of 2.08, only slightly fainter than Polaris. Kochab and magnitude 3 Gamma Ursae Minoris have been called the ""guardians of the pole star"". Planets have been detected orbiting four of the stars, including Kochab. The constellation also contains an isolated neutron star—Calvera—and H1504+65, the hottest white dwarf yet discovered with a surface temperature of 200,000 K.