Comparison of low- and high-mass star formation
... 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 dense gas in the “core” is the key to the long duration of high mass accretion rate for the most massive object, which is many tim ...
... 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 dense gas in the “core” is the key to the long duration of high mass accretion rate for the most massive object, which is many tim ...
Process of Science: PreMainSequence Stellar Life Tracks on the HR
... If you watch the position of the red dot on the HR diagram as the interactive figure plays, you will see that the dot is highest — meaning the object is most luminous— when it is a protostar and therefore does not yet have internal fusion. This fact can be a little surprising, but do not forget tha ...
... If you watch the position of the red dot on the HR diagram as the interactive figure plays, you will see that the dot is highest — meaning the object is most luminous— when it is a protostar and therefore does not yet have internal fusion. This fact can be a little surprising, but do not forget tha ...
Abstract - UChicago High Energy Physics
... [10, 11] above disks can be home to nucleosynthesis, including perhaps the r-process, depending on neutrino flavor composition [2, 9, 12–16]. The neutrino flavor composition above the neutrino trapping surface depends not only on thermodynamics in the trapped regions, but also the oscillation of neu ...
... [10, 11] above disks can be home to nucleosynthesis, including perhaps the r-process, depending on neutrino flavor composition [2, 9, 12–16]. The neutrino flavor composition above the neutrino trapping surface depends not only on thermodynamics in the trapped regions, but also the oscillation of neu ...
19_Testbank - Lick Observatory
... A) Planets around stars are known to be extremely rare. B) Halo stars formed in an environment where there were few heavy elements to create rocky ...
... A) Planets around stars are known to be extremely rare. B) Halo stars formed in an environment where there were few heavy elements to create rocky ...
The extreme ultraviolet and X-ray Sun in Time: High
... considered ages). We use additional constraints for pre-mainsequence (PMS) rotation from the ≈2 Myr cluster NGC 6530 (28 stars; Henderson & Stassun 2012) and the ≈12 Myr cluster h Per (117 stars; Moraux et al. 2013). For NGC 6530, the 10th, 50th, and 90th percentiles are at 2.7Ω , 6.2Ω, and 35.1Ω ...
... considered ages). We use additional constraints for pre-mainsequence (PMS) rotation from the ≈2 Myr cluster NGC 6530 (28 stars; Henderson & Stassun 2012) and the ≈12 Myr cluster h Per (117 stars; Moraux et al. 2013). For NGC 6530, the 10th, 50th, and 90th percentiles are at 2.7Ω , 6.2Ω, and 35.1Ω ...
San Pedro Mártir observations of microvariability in obscured quasars
... campaign, we conclude that we cannot confirm microvariability in this source. J1430+1339 was observed on March 28 and March 30, 2011. During the two observing nights, both the target and the comparison star exhibited very contradictory results from ANOVA. We were unable to find a comparison star tha ...
... campaign, we conclude that we cannot confirm microvariability in this source. J1430+1339 was observed on March 28 and March 30, 2011. During the two observing nights, both the target and the comparison star exhibited very contradictory results from ANOVA. We were unable to find a comparison star tha ...
Astronomy 112: The Physics of Stars Class 14 Notes: The Main
... This is the luminosity-effective temperature relationship for a polytropic star with arbitrary γ. For a fully convective star composed of non-relativistic ideal gas, γ = 5/3, and for p − p chain burning, ν = 4. Plugging in these values gives a value of 3.7 for the coefficient. This is shallower than ...
... This is the luminosity-effective temperature relationship for a polytropic star with arbitrary γ. For a fully convective star composed of non-relativistic ideal gas, γ = 5/3, and for p − p chain burning, ν = 4. Plugging in these values gives a value of 3.7 for the coefficient. This is shallower than ...
Compare/Order Decimals
... B. 0.6 + 0.008 + 0.0007 Standard form: 0.6087 Word form: six thousand eighty-seven tenthousandths Course 1 ...
... B. 0.6 + 0.008 + 0.0007 Standard form: 0.6087 Word form: six thousand eighty-seven tenthousandths Course 1 ...
Article PDF - IOPscience
... performed with HSTphot (Dolphin 2000), a photometry package specifically designed to handle the undersampled PSF of the WFPC2/HST data. A number of initial pre-processing steps are required before running the photometry procedure. First, image defects such as bad columns and saturated pixels are ide ...
... performed with HSTphot (Dolphin 2000), a photometry package specifically designed to handle the undersampled PSF of the WFPC2/HST data. A number of initial pre-processing steps are required before running the photometry procedure. First, image defects such as bad columns and saturated pixels are ide ...
in search of antimatter in the universe
... instead consider a much larger object, such as the gas shell of a supernova, then we obtain Figure 12. In this case, the emission line is just visible up to 600 parsecs, after which the brightness drops below 0.1 photons s-1m-2, and the emission line will be hard to distinguish from background noise ...
... instead consider a much larger object, such as the gas shell of a supernova, then we obtain Figure 12. In this case, the emission line is just visible up to 600 parsecs, after which the brightness drops below 0.1 photons s-1m-2, and the emission line will be hard to distinguish from background noise ...
cohen_paris_v2_may2009 - Astronomy at Swarthmore College
... Photoelectric absorption’s effect on the profile shapes can be used as a mass-loss rate diagnostic: massloss rates are lower than previously thought. ...
... Photoelectric absorption’s effect on the profile shapes can be used as a mass-loss rate diagnostic: massloss rates are lower than previously thought. ...
NGC 6231: a young open cluster under X-rays
... • dispersion ~ 40% much more limited than previously admitted • within our sample, O-type star X-ray variability only seen for probable CWBs + only identified mechanism that produces a significant deviation from the ‘canonical’ relation 20-Dec-2006 ...
... • dispersion ~ 40% much more limited than previously admitted • within our sample, O-type star X-ray variability only seen for probable CWBs + only identified mechanism that produces a significant deviation from the ‘canonical’ relation 20-Dec-2006 ...
sections 16-18 instructor notes
... directly upon the nature of the orbits for the stars in the group. For stars in nearly circular orbits no asymmetric drift is expected, while for stars having a mix of very eccentric orbits the asymmetric drift should be fairly significant. A group of stars having the latter properties will also exh ...
... directly upon the nature of the orbits for the stars in the group. For stars in nearly circular orbits no asymmetric drift is expected, while for stars having a mix of very eccentric orbits the asymmetric drift should be fairly significant. A group of stars having the latter properties will also exh ...
Introduction to Galaxies - West Jefferson Local Schools
... At the beginning of the 20th century, what we now call spiral galaxies were referred to as “spiral nebulae” and most astronomers believed them to be clouds of gas and stars associated with our own Milky Way. Edwin P. Hubble (1889-1953) ...
... At the beginning of the 20th century, what we now call spiral galaxies were referred to as “spiral nebulae” and most astronomers believed them to be clouds of gas and stars associated with our own Milky Way. Edwin P. Hubble (1889-1953) ...
sections 16-18 instructor notes
... directly upon the nature of the orbits for the stars in the group. For stars in nearly circular orbits no asymmetric drift is expected, while for stars having a mix of very eccentric orbits the asymmetric drift should be fairly significant. A group of stars having the latter properties will also exh ...
... directly upon the nature of the orbits for the stars in the group. For stars in nearly circular orbits no asymmetric drift is expected, while for stars having a mix of very eccentric orbits the asymmetric drift should be fairly significant. A group of stars having the latter properties will also exh ...
Document
... 3. The halo. Old stars (including the globular clusters) and very dilute interstellar matter form a roughly spherical Galactic halo around the disk. The inner part of the halo is at least as large across as the disk, perhaps 60,000 light-years in radius. The gas in the inner halo is hot, 100,000 K, ...
... 3. The halo. Old stars (including the globular clusters) and very dilute interstellar matter form a roughly spherical Galactic halo around the disk. The inner part of the halo is at least as large across as the disk, perhaps 60,000 light-years in radius. The gas in the inner halo is hot, 100,000 K, ...
Satellities - stoweschools.com
... Velocity of the Geostationary Satellite with respect to the sun ...
... Velocity of the Geostationary Satellite with respect to the sun ...
November, 2015 - The Baton Rouge Astronomical Society
... stars with a separation of 1.8 arc-seconds, and an orbital period of 933 years. Fum al Samakah (Beta Psc), “Mouth of the Fish”, mag. 4.48, 23 03 52.61 +03 49 12.3, is a blue-white, main sequence star. Simmah (Gamma Psc), mag. 3.70, 23 17 09.49 +03 16 56.1, is a yellow giant star, is in the asterism ...
... stars with a separation of 1.8 arc-seconds, and an orbital period of 933 years. Fum al Samakah (Beta Psc), “Mouth of the Fish”, mag. 4.48, 23 03 52.61 +03 49 12.3, is a blue-white, main sequence star. Simmah (Gamma Psc), mag. 3.70, 23 17 09.49 +03 16 56.1, is a yellow giant star, is in the asterism ...
Common Envelope Evolution Leading to Supernovae with Dense
... by a supernova can also be considered for the white dwarf case. A white dwarf spirals into the envelope of an evolved companion and continues to the core where strong accretion gives rise to a thermonuclear explosion. This scenario would be compatible with a double degenerate origin for Type Ia supe ...
... by a supernova can also be considered for the white dwarf case. A white dwarf spirals into the envelope of an evolved companion and continues to the core where strong accretion gives rise to a thermonuclear explosion. This scenario would be compatible with a double degenerate origin for Type Ia supe ...
- IRSF: Past and Future
... Gamma-ray binaries are a subclass of X-ray binaries that emit the majority of the energy in the gamma-ray band. They are comprised of a compact object and a massive (>10 Msun) star with a circumstellar disk or strong stellar wind. Their emission, ranging from radio to TeV gamma-rays, show variations ...
... Gamma-ray binaries are a subclass of X-ray binaries that emit the majority of the energy in the gamma-ray band. They are comprised of a compact object and a massive (>10 Msun) star with a circumstellar disk or strong stellar wind. Their emission, ranging from radio to TeV gamma-rays, show variations ...
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.