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... Thought Question What happens in a low-mass star when core temperature rises enough for helium fusion to begin? A. Helium fusion slowly starts up. B. Hydrogen fusion stops. C. Helium fusion rises very sharply. (Hint: Degeneracy pressure is the main form of pressure in the inert helium core.) ...
... Thought Question What happens in a low-mass star when core temperature rises enough for helium fusion to begin? A. Helium fusion slowly starts up. B. Hydrogen fusion stops. C. Helium fusion rises very sharply. (Hint: Degeneracy pressure is the main form of pressure in the inert helium core.) ...
The 2008 RBSE Journal - National Optical Astronomy Observatory
... starburst galaxies. After amassing a reasonable amount of galaxies (about 70), we calculated the ratios between the prominent emission lines. To find these ratios we divided the higher wavelength by the shorter one. We had to find the ratios of all the emission lines in order to discover which eleme ...
... starburst galaxies. After amassing a reasonable amount of galaxies (about 70), we calculated the ratios between the prominent emission lines. To find these ratios we divided the higher wavelength by the shorter one. We had to find the ratios of all the emission lines in order to discover which eleme ...
A very massive runaway star from Cygnus OB2⋆
... Although the identication of BD+43 3654 as a likely runaway star dates back to van Buren & McCray (1988), no spectral classication is available in that work. Subsequent papers by van Buren et al. (1995) and Noriega-Crespo et al. (1997) refer to the star as a unspecied B-type but do not report ded ...
... Although the identication of BD+43 3654 as a likely runaway star dates back to van Buren & McCray (1988), no spectral classication is available in that work. Subsequent papers by van Buren et al. (1995) and Noriega-Crespo et al. (1997) refer to the star as a unspecied B-type but do not report ded ...
Asteroseismic constraints on Asymmetric Dark Matter: Light particles
... For comparison of ADM and WIMP accumulation, figures 1a and 1b show analytical approximations to the present solar fraction of the number of trapped DM particles in the ADM scenario relative to the WIMP picture. The number of ADM particles trapped inside the Sun is greater than that of WIMPs by a fa ...
... For comparison of ADM and WIMP accumulation, figures 1a and 1b show analytical approximations to the present solar fraction of the number of trapped DM particles in the ADM scenario relative to the WIMP picture. The number of ADM particles trapped inside the Sun is greater than that of WIMPs by a fa ...
Teacher`s Guide - Cornell Science Inquiry Partnerships
... Astronomy, Earth Science Audience This activity is aimed at a high school audience, but it could easily be modified for use with middle school students. Time Required The essential activities can be covered in 40 minutes, or the entire project can be stretched to 4 hours or even much longer. (In the ...
... Astronomy, Earth Science Audience This activity is aimed at a high school audience, but it could easily be modified for use with middle school students. Time Required The essential activities can be covered in 40 minutes, or the entire project can be stretched to 4 hours or even much longer. (In the ...
Measuring the Stars Section 29.2
... emitted per second, or watts. The Sun’s luminosity is about 3.85 × 1026 W. The values for other stars vary widely, from about 0.0001 to more than 1 million times the Sun’s luminosity. No other stellar property varies as much. ...
... emitted per second, or watts. The Sun’s luminosity is about 3.85 × 1026 W. The values for other stars vary widely, from about 0.0001 to more than 1 million times the Sun’s luminosity. No other stellar property varies as much. ...
Review: How does a star`s mass determine its life story?
... What is a neutron star? • A neutron star is the ball of neutrons created by the collapse of the iron core in a massive star supernova. • How were neutron stars discovered? • Neutron stars spin rapidly when they are born, and their strong magnetic fields can direct beams of radiation that sweep throu ...
... What is a neutron star? • A neutron star is the ball of neutrons created by the collapse of the iron core in a massive star supernova. • How were neutron stars discovered? • Neutron stars spin rapidly when they are born, and their strong magnetic fields can direct beams of radiation that sweep throu ...
PH607lec10-4gal2
... disk galaxy. Estimate the luminosity and maximum circular velocity of an exponential disk of stars. Luminosity Empirically, disk galaxies have an exponential surface brightness ...
... disk galaxy. Estimate the luminosity and maximum circular velocity of an exponential disk of stars. Luminosity Empirically, disk galaxies have an exponential surface brightness ...
Chapter 6: Stellar Evolution (part 2)
... I But, physically most of the accreted materials is fused to carbon and oxygen during nova and possibly ejected. So all these need to lead to the increase of the WD mass. I The accumulated X-ray emission from such accreting sources, as observed from nearby galaxies, seems to be far less than require ...
... I But, physically most of the accreted materials is fused to carbon and oxygen during nova and possibly ejected. So all these need to lead to the increase of the WD mass. I The accumulated X-ray emission from such accreting sources, as observed from nearby galaxies, seems to be far less than require ...
aaswinter06
... • The detailed light curve is unlike that of a supernova, nova, or any other type of variable star (1,2,3). During the outburst, V838 Mon was found to have a maximum effective temperature of an A – F star at the optical maximum in February 2002. The effective temperature then cooled to a very low ~8 ...
... • The detailed light curve is unlike that of a supernova, nova, or any other type of variable star (1,2,3). During the outburst, V838 Mon was found to have a maximum effective temperature of an A – F star at the optical maximum in February 2002. The effective temperature then cooled to a very low ~8 ...
Part1
... 4. How do you pull physical information about #2 from #3? Radio/mm Lines & Continuum, Dust Emission, Starlight 5. What are some of the basic galaxy scaling relations? Tully-Fisher, Mass-SFR, Mass-Metallicity, Gas-SFR, Mass-Gas ...
... 4. How do you pull physical information about #2 from #3? Radio/mm Lines & Continuum, Dust Emission, Starlight 5. What are some of the basic galaxy scaling relations? Tully-Fisher, Mass-SFR, Mass-Metallicity, Gas-SFR, Mass-Gas ...
Homologous Stellar Models and Polytropes Main Sequence Stars
... • As already shown by homology, L ∝ M a5 where for low-mass and highmass stars a5 = 5.5 and a5 = 3.0 were deduced respectively. The flattening at higher masses is due to the increased contribution of radiation pressure in the central core, which helps support the star and decreases the central tempe ...
... • As already shown by homology, L ∝ M a5 where for low-mass and highmass stars a5 = 5.5 and a5 = 3.0 were deduced respectively. The flattening at higher masses is due to the increased contribution of radiation pressure in the central core, which helps support the star and decreases the central tempe ...
The Earth and Man In the Universe
... attention of the thoughtful. This great circle divides the heavens into two hemispheres, making an angle of about 63 0 with the ecliptic, so that it does not pass very far from either the North or South pole. Its appearance is known to be the result of the massing together of millions of stars, the ...
... attention of the thoughtful. This great circle divides the heavens into two hemispheres, making an angle of about 63 0 with the ecliptic, so that it does not pass very far from either the North or South pole. Its appearance is known to be the result of the massing together of millions of stars, the ...
The Parallax Activity: Measuring the Distances to
... 2. Running the activity to collect data Divide your class into teams of four students each. Pro- vide each team with a quadrant. If you have time, it would be good for each team to make their own quadrant. Take the class outside to where you have marked ...
... 2. Running the activity to collect data Divide your class into teams of four students each. Pro- vide each team with a quadrant. If you have time, it would be good for each team to make their own quadrant. Take the class outside to where you have marked ...
– 1 – 1. Chemical Evolution 1.1.
... suggests that the Salpeter IMF is too steep to fit the observations for low mass stars below 0.5M⊙ , and that a flatter slope is required, reaching −0.3 ± 0.7 for 0.01 < M/M⊙ < 0.08. Note that the transformation from luminosity to mass (the IMF is a function of stellar mass) is not as well determine ...
... suggests that the Salpeter IMF is too steep to fit the observations for low mass stars below 0.5M⊙ , and that a flatter slope is required, reaching −0.3 ± 0.7 for 0.01 < M/M⊙ < 0.08. Note that the transformation from luminosity to mass (the IMF is a function of stellar mass) is not as well determine ...
First young loose association in the northern hemisphere?
... !!Most stars detected by the ROSAT mission are younger than 1 Gyr (e.g. Motch et al. 1997). !!Taking account this property, Guillout et al. (1999) cross-correlated the ROSAT All-Sky Survey (RASS) with the Tycho catalogue creating the largest ("14 000 active stars) and most comprehensive set of late- ...
... !!Most stars detected by the ROSAT mission are younger than 1 Gyr (e.g. Motch et al. 1997). !!Taking account this property, Guillout et al. (1999) cross-correlated the ROSAT All-Sky Survey (RASS) with the Tycho catalogue creating the largest ("14 000 active stars) and most comprehensive set of late- ...
PSU/TCfA search for planets around evolved stars
... High precision stellar radial velocity measurements are extensively used to detect the reflex motion of a star due to planetary companion. Radial velocity method, however is not sensitive only to the motion of a star around the center of mass of star-planet system. Changes in line shapes arising fro ...
... High precision stellar radial velocity measurements are extensively used to detect the reflex motion of a star due to planetary companion. Radial velocity method, however is not sensitive only to the motion of a star around the center of mass of star-planet system. Changes in line shapes arising fro ...
X-ray binaries
... The latest large catalogue (Li et al. arXiv: 0707.0544) includes 187 galactic and Magellanic Clouds LMXBs with NSs and BHs as accreting components. Donors can be WDs, or normal low-mass stars (main sequence or sub-giants). Many sources are found in globular clusters. Also there are more and more LMX ...
... The latest large catalogue (Li et al. arXiv: 0707.0544) includes 187 galactic and Magellanic Clouds LMXBs with NSs and BHs as accreting components. Donors can be WDs, or normal low-mass stars (main sequence or sub-giants). Many sources are found in globular clusters. Also there are more and more LMX ...
Letter to the Editor The formation of bipolar planetary nebulae
... and one might expect that this will have an effect on the formation of the nebula. A typical post-AGB track in the HR-diagram consists of two parts (Paczyński 1971). Initially the star contracts, evolving to higher effective temperatures at a constant luminosity; then as the energy production stops ...
... and one might expect that this will have an effect on the formation of the nebula. A typical post-AGB track in the HR-diagram consists of two parts (Paczyński 1971). Initially the star contracts, evolving to higher effective temperatures at a constant luminosity; then as the energy production stops ...
Perseus (constellation)
Perseus, named after the Greek mythological hero Perseus, is a constellation in the northern sky. It was one of 48 listed by the 2nd-century astronomer Ptolemy and among the 88 modern constellations defined by the International Astronomical Union (IAU). It is located in the northern celestial hemisphere near several other constellations named after legends surrounding Perseus, including Andromeda to the west and Cassiopeia to the north. Perseus is also bordered by Aries and Taurus to the south, Auriga to the east, Camelopardalis to the north, and Triangulum to the west.The galactic plane of the Milky Way passes through Perseus but is mostly obscured by molecular clouds. The constellation's brightest star is the yellow-white supergiant Alpha Persei (also called Mirfak), which shines at magnitude 1.79. It and many of the surrounding stars are members of an open cluster known as the Alpha Persei Cluster. The best-known star, however, is Algol (Beta Persei), linked with ominous legends because of its variability, which is noticeable to the naked eye. Rather than being an intrinsically variable star, it is an eclipsing binary. Other notable star systems in Perseus include X Persei, a binary system containing a neutron star, and GK Persei, a nova that peaked at magnitude 0.2 in 1901. The Double Cluster, comprising two open clusters quite near each other in the sky, was known to the ancient Chinese. The constellation gives its name to the Perseus Cluster (Abell 426), a massive galaxy cluster located 250 million light-years from Earth. It hosts the radiant of the annual Perseids meteor shower—one of the most prominent meteor showers in the sky.