Catalogs of Hot White Dwarfs in the Milky Way from GALEX`s
... asymptotic giant branch (AGB) and planetary nebula (PN) phases, in which they shed much of their mass. The ejected material enriches the interstellar medium (ISM) with newly synthesized nuclear products (mainly He, C, N, and possibly O), to different extents, depending on the initial stellar mass an ...
... asymptotic giant branch (AGB) and planetary nebula (PN) phases, in which they shed much of their mass. The ejected material enriches the interstellar medium (ISM) with newly synthesized nuclear products (mainly He, C, N, and possibly O), to different extents, depending on the initial stellar mass an ...
The occurrence of nitrogen-enhanced metal
... Most carbon-enhanced metal-poor (CEMP) stars are thought to result from past mass transfer of He-burning material from an asymptotic giant branch (AGB) star to a low-mass companion star, which we now observe as a CEMP star. Because AGB stars of intermediate mass efficiently cycle carbon into nitroge ...
... Most carbon-enhanced metal-poor (CEMP) stars are thought to result from past mass transfer of He-burning material from an asymptotic giant branch (AGB) star to a low-mass companion star, which we now observe as a CEMP star. Because AGB stars of intermediate mass efficiently cycle carbon into nitroge ...
KIC 8462852 Faded Throughout the Kepler Mission
... first is a long-term dimming at a linear rate from the beginning of the Kepler mission until approximately Quarter 13. The dimming then increases rapidly such that the observed flux from the star decreases by approximately 2.5% over 200 days. For the final 200 days of the Kepler mission, the light c ...
... first is a long-term dimming at a linear rate from the beginning of the Kepler mission until approximately Quarter 13. The dimming then increases rapidly such that the observed flux from the star decreases by approximately 2.5% over 200 days. For the final 200 days of the Kepler mission, the light c ...
betelgeuse and the red supergiants
... (and potentially leave behind) the realm of the red supergiants. Stars with birth masses < 15 M⊙ evolve along a red supergiant branch which takes the star on a steep path towards higher luminosity (and somewhat cooler temperature). These branches are more pronounced for lower masses, and hence the l ...
... (and potentially leave behind) the realm of the red supergiants. Stars with birth masses < 15 M⊙ evolve along a red supergiant branch which takes the star on a steep path towards higher luminosity (and somewhat cooler temperature). These branches are more pronounced for lower masses, and hence the l ...
STRUCTURAL CHARACTERISTICS AND STELLAR
... Table 2 contains the colors of those galaxies observed through all four UBV I lters. Each color has three entries. The rst is the color of the inner regions as measured through a small (1000 ) aperture. In some cases, this color represents a true color of the bulge component while in others it re ...
... Table 2 contains the colors of those galaxies observed through all four UBV I lters. Each color has three entries. The rst is the color of the inner regions as measured through a small (1000 ) aperture. In some cases, this color represents a true color of the bulge component while in others it re ...
Research paper
... of ∼414 pc (Menten et al. 2007; Goddi et al. 2011a) is the densest and most molecule-rich part of the degree-long 2,200 M Integral-Shaped Filament (Johnstone & Bally 1999) in the 50,000 M Orion A cloud (Bally et al. 1987). OMC1 contains the ∼ 1 − 2 × 104 L but visually obscured Becklin-Neugebauer ...
... of ∼414 pc (Menten et al. 2007; Goddi et al. 2011a) is the densest and most molecule-rich part of the degree-long 2,200 M Integral-Shaped Filament (Johnstone & Bally 1999) in the 50,000 M Orion A cloud (Bally et al. 1987). OMC1 contains the ∼ 1 − 2 × 104 L but visually obscured Becklin-Neugebauer ...
distribution and properties of a sample of massive young stars
... earliest stages of their evolution are therefore hidden behind many magnitudes of visual extinction, only observable at infrared (IR) and millimetre wavelengths. Moreover, massive stars are known to form exclusively in clusters (e.g. de Wit et al. 2004), which makes it difficult to attribute derived ...
... earliest stages of their evolution are therefore hidden behind many magnitudes of visual extinction, only observable at infrared (IR) and millimetre wavelengths. Moreover, massive stars are known to form exclusively in clusters (e.g. de Wit et al. 2004), which makes it difficult to attribute derived ...
the reality of the wolf 630 moving group - TigerPrints
... the efficient evaporation of younger clusters (i.e. interactions with giant molecular clouds Spitzer (1958)): they must either be formed outside of the disk or dynamically evolve there through some form of non-disruptive heating. Clearly open clusters, both young and old, are valuable targets in pie ...
... the efficient evaporation of younger clusters (i.e. interactions with giant molecular clouds Spitzer (1958)): they must either be formed outside of the disk or dynamically evolve there through some form of non-disruptive heating. Clearly open clusters, both young and old, are valuable targets in pie ...
Carbon-enhanced metal-poor stars: a window on AGB
... composition of the intershell region is saved in a table as a function of three parameters: the mass of the star at the beginning of the TP-AGB phase, the thermal-pulse number, and the mass of the PMZ, MPMZ . The surface abundances of an AGB star of mass M∗ evolve in time and are recalculated at eve ...
... composition of the intershell region is saved in a table as a function of three parameters: the mass of the star at the beginning of the TP-AGB phase, the thermal-pulse number, and the mass of the PMZ, MPMZ . The surface abundances of an AGB star of mass M∗ evolve in time and are recalculated at eve ...
DISSERTATION
... The AGB is the late evolutionary stage of stars with masses below 8 M! . These stars are characterised by a C-O degenerated core and 2 shell with ongoing nuclear reactions (He and H shells), a convective envelope and a very extended atmosphere with molecules and dust formation. As a star evolves alo ...
... The AGB is the late evolutionary stage of stars with masses below 8 M! . These stars are characterised by a C-O degenerated core and 2 shell with ongoing nuclear reactions (He and H shells), a convective envelope and a very extended atmosphere with molecules and dust formation. As a star evolves alo ...
Follow-up observations of extremely metal
... extremely rare as illustrates the fact that, despite substantial efforts, only 4 stars are known at [Fe/H]< −5. Theoretical calculations show that the lack of metals in the gas in the early universe prevents gas clouds from fragmenting effectively, and shifts the initial mass function to very high m ...
... extremely rare as illustrates the fact that, despite substantial efforts, only 4 stars are known at [Fe/H]< −5. Theoretical calculations show that the lack of metals in the gas in the early universe prevents gas clouds from fragmenting effectively, and shifts the initial mass function to very high m ...
Physical Properties of Wolf-Rayet Stars
... In particular, Wolf-Rayet (WR) stars typically have wind densities an order of magnitude higher than massive O stars. They contribute to the chemical enrichment of galaxies, they are the prime candidates for the immediate progenitors of long, soft gamma-ray bursts (GRBs, Woosley & Bloom 2006), and t ...
... In particular, Wolf-Rayet (WR) stars typically have wind densities an order of magnitude higher than massive O stars. They contribute to the chemical enrichment of galaxies, they are the prime candidates for the immediate progenitors of long, soft gamma-ray bursts (GRBs, Woosley & Bloom 2006), and t ...
The occurrence of nitrogen-enhanced metal
... stars that have had significant accretion of He-burning products (either carbon or nitrogen) can be based on the C + N abundance, because CN-cycling during HBB conserves the total number of C + N nuclei. If carbon is enhanced by a factor greater than 10 (corresponding to our CEMP criterion [C/Fe] ≥ ...
... stars that have had significant accretion of He-burning products (either carbon or nitrogen) can be based on the C + N abundance, because CN-cycling during HBB conserves the total number of C + N nuclei. If carbon is enhanced by a factor greater than 10 (corresponding to our CEMP criterion [C/Fe] ≥ ...
Synthetic Light Curves of Shocked Dense Circumstellar Shells
... get the same luminosity is small (1.7 × 104 K) and it is close to the observed values. Although the bolometric LCs at these epochs seem to follow the observed bolometric LC, we should be careful because the bolometric LC of SN 2006gy is obtained by the R-band LC without the bolometric correction. We ...
... get the same luminosity is small (1.7 × 104 K) and it is close to the observed values. Although the bolometric LCs at these epochs seem to follow the observed bolometric LC, we should be careful because the bolometric LC of SN 2006gy is obtained by the R-band LC without the bolometric correction. We ...
chemical abundances for a-and f-type supergiant stars
... have already reached the red supergiant stage but eventually evolve back into a blue supergiant phase (Walmswell et al. 2015). During the red supergiant phase, the convective zone mixes materials of the H-burning shell, which are subsequently released to the surface by the 1DUP event, causing change ...
... have already reached the red supergiant stage but eventually evolve back into a blue supergiant phase (Walmswell et al. 2015). During the red supergiant phase, the convective zone mixes materials of the H-burning shell, which are subsequently released to the surface by the 1DUP event, causing change ...
Herschel far-infrared observations of the Carina Nebula complex⋆
... Key words. stars: formation – circumstellar matter – stars: protostars – stars: luminosity function, mass function – ISM: individual objects: NGC 3372 – stars: individual: η Carinae ...
... Key words. stars: formation – circumstellar matter – stars: protostars – stars: luminosity function, mass function – ISM: individual objects: NGC 3372 – stars: individual: η Carinae ...
RUPRECHT 147: THE OLDEST NEARBY OPEN CLUSTER AS A
... clusters form the basis of our understanding of stellar evolution, and the effects of abundance, age, and mass on stars. When fully characterized with precise ages, distances, and metallicities, these clusters become touchstones for similar stars in the field and test models of stellar evolution and ...
... clusters form the basis of our understanding of stellar evolution, and the effects of abundance, age, and mass on stars. When fully characterized with precise ages, distances, and metallicities, these clusters become touchstones for similar stars in the field and test models of stellar evolution and ...
The evolution and explosion of massive stars
... Like all true stars, massive stars are gravitationally confined thermonuclear reactors whose composition evolves as energy is lost to radiation and neutrinos. Unlike lower-mass stars ( M ⱗ8M 䉺 ) , however, no point is ever reached at which a massive star can be fully supported by electron degeneracy ...
... Like all true stars, massive stars are gravitationally confined thermonuclear reactors whose composition evolves as energy is lost to radiation and neutrinos. Unlike lower-mass stars ( M ⱗ8M 䉺 ) , however, no point is ever reached at which a massive star can be fully supported by electron degeneracy ...
Radial velocity planet detection biases at the stellar rotational period
... using the approximate prescription given by Aigrain et al. (2012), which yielded semi-amplitudes typically between 2 and 15 m s−1 , which are typical of active stars with high-amplitude photometric variability like those we have selected. We note that plages and faculae, which may cause significant ...
... using the approximate prescription given by Aigrain et al. (2012), which yielded semi-amplitudes typically between 2 and 15 m s−1 , which are typical of active stars with high-amplitude photometric variability like those we have selected. We note that plages and faculae, which may cause significant ...
Photometric catalog of nearby globular clusters
... In the next subsections, we briefly present the single CMDs and clusters, and give some references to the best existing CMDs. This does not pretend to be a complete bibliographical catalog: a large number of CMDs are available in the literature for many of the clusters of this survey; we will concen ...
... In the next subsections, we briefly present the single CMDs and clusters, and give some references to the best existing CMDs. This does not pretend to be a complete bibliographical catalog: a large number of CMDs are available in the literature for many of the clusters of this survey; we will concen ...
The chemical composition of two supergiants in the dwarf
... dwarf irregular galaxies appear to have undergone bursts of star formation during their histories and thus should show a variety of α/Fe ratios throughout their evolution, but they are too distant for detailed analysis of their red giant branch (=RGB, stars that can sample ages >1 Gyr). It is possib ...
... dwarf irregular galaxies appear to have undergone bursts of star formation during their histories and thus should show a variety of α/Fe ratios throughout their evolution, but they are too distant for detailed analysis of their red giant branch (=RGB, stars that can sample ages >1 Gyr). It is possib ...
Measuring Reddening with SDSS Stellar Spectra and Recalibrating
... about 500,000 stars (Aihara et al. 2011). The SEGUE Stellar Parameter Pipeline (Lee et al. 2008a, SSPP) has uniformly processed these spectra to measure the temperature, metallicity, and gravity of each of these stars using a variety of methods, including ones that are independent of the observed co ...
... about 500,000 stars (Aihara et al. 2011). The SEGUE Stellar Parameter Pipeline (Lee et al. 2008a, SSPP) has uniformly processed these spectra to measure the temperature, metallicity, and gravity of each of these stars using a variety of methods, including ones that are independent of the observed co ...
Variability of young solar-type stars: Spot cycles, rotation
... akin to the 11 year spot cycle of the Sun, and other possible regularities present in the distribution of the starspots. Measurements of the chromospheric emission level by high resolution spectroscopy will furthermore directly provide useful estimates of the activity level of a star. Despite the fa ...
... akin to the 11 year spot cycle of the Sun, and other possible regularities present in the distribution of the starspots. Measurements of the chromospheric emission level by high resolution spectroscopy will furthermore directly provide useful estimates of the activity level of a star. Despite the fa ...
Evolution of Stars and Stellar Populations
... properties (i.e. evolution of effective temperatures, luminosities, surface chemical abundances) of stars, as a function of their initial mass and chemical composition. The next chapter describes the steps (often missing in stellar evolution books) necessary to transform the results from theoretical ...
... properties (i.e. evolution of effective temperatures, luminosities, surface chemical abundances) of stars, as a function of their initial mass and chemical composition. The next chapter describes the steps (often missing in stellar evolution books) necessary to transform the results from theoretical ...
An atlas of 2.4 to 4.1 mu m ISO/SWS spectra of early - UvA-DARE
... four preset overlapping sub-bands. These are defined in Table 4. The integration time per target is fixed, therefore the S/N ratio mainly depends on the brightness of the source. Combining the nominal and Post-Helium program AOT01 speed 4 observations, we collected 69 ISO/SWS spectra. However, two t ...
... four preset overlapping sub-bands. These are defined in Table 4. The integration time per target is fixed, therefore the S/N ratio mainly depends on the brightness of the source. Combining the nominal and Post-Helium program AOT01 speed 4 observations, we collected 69 ISO/SWS spectra. However, two t ...