Red Supergiants as Cosmic Abundance Probes
... method requires measurements of auroral lines, such as [O III] 436.3 nm, which allows the observer to uniquely determine the gas temperature and, crucially, the abundance of the element. Unfortunately, these auroral lines are often very weak, especially at high metallicity. This means that one must ...
... method requires measurements of auroral lines, such as [O III] 436.3 nm, which allows the observer to uniquely determine the gas temperature and, crucially, the abundance of the element. Unfortunately, these auroral lines are often very weak, especially at high metallicity. This means that one must ...
Summer Sky Tour
... sun is a yellow star, about 10,000°F at the surface. A red star is about half the sun's surface temperature, whereas a blue star is three to five times as hot as the sun. White stars are somewhere between the yellow ones and blue ones. Now, all stars are made of pretty much the same stuff -- about 9 ...
... sun is a yellow star, about 10,000°F at the surface. A red star is about half the sun's surface temperature, whereas a blue star is three to five times as hot as the sun. White stars are somewhere between the yellow ones and blue ones. Now, all stars are made of pretty much the same stuff -- about 9 ...
egg nebula - IOPscience
... (green) images, together with the WFPC2 (blue) image (from STWS98). Each of the individual images in Figure 1 are shown separately in Figure 2 (Plate L45, panels a–c). The sharp structures in each image in Figure 1 have been modestly enhanced. Two bright spindle-like bubbles can be seen in the infra ...
... (green) images, together with the WFPC2 (blue) image (from STWS98). Each of the individual images in Figure 1 are shown separately in Figure 2 (Plate L45, panels a–c). The sharp structures in each image in Figure 1 have been modestly enhanced. Two bright spindle-like bubbles can be seen in the infra ...
Search for Life in the Universe
... Evidence for microbal life on Earth under harsh conditions Search for evidence of microbes • Controversial Martian microbes ...
... Evidence for microbal life on Earth under harsh conditions Search for evidence of microbes • Controversial Martian microbes ...
Counter-rotating Stellar Components in Simulated Disk Galaxies
... major axis shows striking bimodality. This bimodality indicates the presence of two disk components, photometrically inseparable, but counterstreaming at projected velocities of 100km/s and +150km/s (Rix et al 1992) ...
... major axis shows striking bimodality. This bimodality indicates the presence of two disk components, photometrically inseparable, but counterstreaming at projected velocities of 100km/s and +150km/s (Rix et al 1992) ...
Lokal fulltext - Chalmers Publication Library
... up in the HR diagram towards larger luminosities. This will happen sooner the more massive the star is: the Sun has a main sequence lifetime of about 10 billion years, compared with only ∼30 million years for a 10 M star. There are several tracks a star may follow in the HR diagram, depending on it ...
... up in the HR diagram towards larger luminosities. This will happen sooner the more massive the star is: the Sun has a main sequence lifetime of about 10 billion years, compared with only ∼30 million years for a 10 M star. There are several tracks a star may follow in the HR diagram, depending on it ...
The Role of the Galaxy in the Dynamical Evolution of
... •Within a Dense Embedded Star Cluster the efficiency of populating the (mostly inner) Oort cloud is 5-20%, depending on the cluster density and stellar orbit. A dense embedded star cluster can reproduce orbits of Sedna and CR105. • Protoplanetary Gas drag produces a size-sorting: large objects like ...
... •Within a Dense Embedded Star Cluster the efficiency of populating the (mostly inner) Oort cloud is 5-20%, depending on the cluster density and stellar orbit. A dense embedded star cluster can reproduce orbits of Sedna and CR105. • Protoplanetary Gas drag produces a size-sorting: large objects like ...
Sources with
... The relative number of stars produced per unit mass interval Derived from the observed luminosity function Power law function of M*g, slope g 2.35 ...
... The relative number of stars produced per unit mass interval Derived from the observed luminosity function Power law function of M*g, slope g 2.35 ...
Mass loss in semi-detached binaries
... stars and post-Main-Sequence expanding single stars. It is to be noted that only a small fraction of the mass lost by the evolved component can be accomodated on the companion. Hence, most of the mass is lost from the system through the outer Lagrangian points, and the more massive primary has essen ...
... stars and post-Main-Sequence expanding single stars. It is to be noted that only a small fraction of the mass lost by the evolved component can be accomodated on the companion. Hence, most of the mass is lost from the system through the outer Lagrangian points, and the more massive primary has essen ...
arXiv:1102.4757v1 [astro-ph.SR] 23 Feb 2011
... to theoretical models, the change in orbital energy must be at least as large as the binding energy of the giant (see Paczynski 1976; Han et al. 2002, 2003). Detailed models of giants at the tip of the red-giant branch that will form sdB stars after the common envelope are given in Hu et al. (2007). ...
... to theoretical models, the change in orbital energy must be at least as large as the binding energy of the giant (see Paczynski 1976; Han et al. 2002, 2003). Detailed models of giants at the tip of the red-giant branch that will form sdB stars after the common envelope are given in Hu et al. (2007). ...
PHE-15 (2007
... What are the main differences between the terrestrial and jovian planets? How does the ring system of jovian planets persist for so long? ...
... What are the main differences between the terrestrial and jovian planets? How does the ring system of jovian planets persist for so long? ...
Connecting Stars, Galaxies and the Universe
... about an order of magnitude less accurate than for binary stars4 At this point we would like to point out the unique abilities of a pointed SIM-Lite mission as compared to ESA's survey mission GAIA. While GAIA will obtain very accurate astrometry, spectroscopy and radial velocities for 10s to 100s o ...
... about an order of magnitude less accurate than for binary stars4 At this point we would like to point out the unique abilities of a pointed SIM-Lite mission as compared to ESA's survey mission GAIA. While GAIA will obtain very accurate astrometry, spectroscopy and radial velocities for 10s to 100s o ...
Slide 1
... excitation by fast particles emitted by the (56)Ni -> (56)Co-> (56)Fe decay. - type Ic: progenitor must be either an extreme WR star, or a binary (Nomoto 1995) - type II: progenitor is a massive red giant ...
... excitation by fast particles emitted by the (56)Ni -> (56)Co-> (56)Fe decay. - type Ic: progenitor must be either an extreme WR star, or a binary (Nomoto 1995) - type II: progenitor is a massive red giant ...
Presentazione di PowerPoint
... and gas is predominantly Keplerian (relativistic effects are minimal), with a component due to the combined gravitational potential of stars, dust, gas, dark matter, and anything else contributing mass to within that region. Beyond the sphere of influence, the gravitational dominance of the SMBH qui ...
... and gas is predominantly Keplerian (relativistic effects are minimal), with a component due to the combined gravitational potential of stars, dust, gas, dark matter, and anything else contributing mass to within that region. Beyond the sphere of influence, the gravitational dominance of the SMBH qui ...
JCMT Debris Disks Survey - Physics and Astronomy
... – Stellar type (100 stars in A, F, G, K, and M) – Stellar age (150 < 1 Gyr and 350 > 1 Gyr) • Boundary is the end of the heavy bombardment phase in the solar system – Presence of a planetary system • 20 are currently known in the sample ...
... – Stellar type (100 stars in A, F, G, K, and M) – Stellar age (150 < 1 Gyr and 350 > 1 Gyr) • Boundary is the end of the heavy bombardment phase in the solar system – Presence of a planetary system • 20 are currently known in the sample ...
PDF hosted at the Radboud Repository of the Radboud University
... lower masses (see Hu et al. 2007, Fig. 3) than EGB 5. In contrast, the masses of most sdB primaries in HW Vir systems constrained by observations seem to be close to the canonical value. However, we point out that reliable mass determinations in such systems are still hampered by severe issues (see ...
... lower masses (see Hu et al. 2007, Fig. 3) than EGB 5. In contrast, the masses of most sdB primaries in HW Vir systems constrained by observations seem to be close to the canonical value. However, we point out that reliable mass determinations in such systems are still hampered by severe issues (see ...
The electron temperature of the inner halo of the Planetary Nebula
... proceed beyond the core nebula into the halo region, where it would interact with halo material to produce the necessary shocks. This is the model favoured by Meaburn et al. (1991) to explain the measured electron temperatures in the outer halo. Whereas the structures in the outer halo also morpholo ...
... proceed beyond the core nebula into the halo region, where it would interact with halo material to produce the necessary shocks. This is the model favoured by Meaburn et al. (1991) to explain the measured electron temperatures in the outer halo. Whereas the structures in the outer halo also morpholo ...
Discovery of Warm and Dense Molecular Gas Surrounding the Ring
... A recent census provides a total of 12 confirmed galactic LBV stars and 23 candidates of such objects (Clark et al. 2005). G79.29+ 0.46 appears as a strong LBV candidate in the sample. Noticed for the first time by Wendker et al. (1991) in a radio map (1420 MHz) of the Cygnus X region, this ringlike ...
... A recent census provides a total of 12 confirmed galactic LBV stars and 23 candidates of such objects (Clark et al. 2005). G79.29+ 0.46 appears as a strong LBV candidate in the sample. Noticed for the first time by Wendker et al. (1991) in a radio map (1420 MHz) of the Cygnus X region, this ringlike ...
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... images of the sky. The subsequent CCD images are then analyzed with accompanying computer software to obtain precise and accurate magnitude measurements over time. The first step is to collect these images from Star Dial. Next, two images of the sky from two different nights need to be aligned and c ...
... images of the sky. The subsequent CCD images are then analyzed with accompanying computer software to obtain precise and accurate magnitude measurements over time. The first step is to collect these images from Star Dial. Next, two images of the sky from two different nights need to be aligned and c ...
protostellar disks under the influence of winds and uv radiation
... Star formation and the creation of protostellar disks generally occur in a crowded environment. Nearby young stars and protostars can influence the disks of their closest neighbors by a combination of outflows and hard radiation. The central stars themselves can have a stellar wind and may produce s ...
... Star formation and the creation of protostellar disks generally occur in a crowded environment. Nearby young stars and protostars can influence the disks of their closest neighbors by a combination of outflows and hard radiation. The central stars themselves can have a stellar wind and may produce s ...
Stellar physics revealed by planet transits
... Disagreements with Models Many low-mass stars are both larger and cooler than predicted by stellar evolution theory ...
... Disagreements with Models Many low-mass stars are both larger and cooler than predicted by stellar evolution theory ...
Numerical Evolu4on of Soliton Stars
... universe was accelera.ng rather than slowing down. • Postulated dark energy (non zero cosmological constant working like a repulsive force). • Present es.mates are about 70% of the energy density is provided by this dark energy. Only about 5% of the density is luminous maPer leaving abo ...
... universe was accelera.ng rather than slowing down. • Postulated dark energy (non zero cosmological constant working like a repulsive force). • Present es.mates are about 70% of the energy density is provided by this dark energy. Only about 5% of the density is luminous maPer leaving abo ...
Bob Mathieu (Wisconsin) – Observations of Open Clusters
... • Photometric mass function to 0.1 Mo in cluster core • Complete census of short-period, solar-type binary population, with orbital elements ...
... • Photometric mass function to 0.1 Mo in cluster core • Complete census of short-period, solar-type binary population, with orbital elements ...
KELT-7b: A HOT JUPITER TRANSITING A BRIGHT V = 8.54
... directly predicted by the rotation velocity measured from the spectrum, combined with the transit depth and shape. The RM effect can therefore provide strong confirmation that the transit signal is due to a planetary-sized object transiting the target star. However, for Jupiter-sized companions, this ...
... directly predicted by the rotation velocity measured from the spectrum, combined with the transit depth and shape. The RM effect can therefore provide strong confirmation that the transit signal is due to a planetary-sized object transiting the target star. However, for Jupiter-sized companions, this ...
Planetary nebula
A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula consisting of an expanding glowing shell of ionized gas ejected from old red giant stars late in their lives. The word ""nebula"" is Latin for mist or cloud and the term ""planetary nebula"" is a misnomer that originated in the 1780s with astronomer William Herschel because when viewed through his telescope, these objects appeared to him to resemble the rounded shapes of planets. Herschel's name for these objects was popularly adopted and has not been changed. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.A mechanism for formation of most planetary nebulae is thought to be the following: at the end of the star's life, during the red giant phase, the outer layers of the star are expelled by strong stellar winds. Eventually, after most of the red giant's atmosphere is dissipated, the exposed hot, luminous core emits ultraviolet radiation to ionize the ejected outer layers of the star. Absorbed ultraviolet light energises the shell of nebulous gas around the central star, appearing as a bright coloured planetary nebula at several discrete visible wavelengths.Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, the products of nucleosynthesis (such as carbon, nitrogen, oxygen and neon), have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances.In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies. About one-fifth are roughly spherical, but the majority are not spherically symmetric. The mechanisms which produce such a wide variety of shapes and features are not yet well understood, but binary central stars, stellar winds and magnetic fields may play a role.