High ions towards white dwarfs: circumstellar line shifts and stellar
... together with a new determination of the photospheric velocities, whenever possible, based on the good detections of heavy ion lines, if present, or on Lyman lines in their absence. As previously found (e.g. Savage & Lehner 2006), for a fraction of the OVI detections the measured velocity is signifi ...
... together with a new determination of the photospheric velocities, whenever possible, based on the good detections of heavy ion lines, if present, or on Lyman lines in their absence. As previously found (e.g. Savage & Lehner 2006), for a fraction of the OVI detections the measured velocity is signifi ...
Classification of Variable Stars
... V1668 Cyg. These are stars in constellations for which all of the letter combinations have been exhausted. (i.e. V746 Oph is the 746th variable to be discovered in Ophiuchus.) Variable star names are determined by a committee appointed by the International Astronomical Union (I.A.U.). The assignment ...
... V1668 Cyg. These are stars in constellations for which all of the letter combinations have been exhausted. (i.e. V746 Oph is the 746th variable to be discovered in Ophiuchus.) Variable star names are determined by a committee appointed by the International Astronomical Union (I.A.U.). The assignment ...
PDF file of document - University of Iowa Astrophysics
... commonly used in all sciences to express mass (kilograms, kg), size (meters, m), and time (seconds, s). It Stars, Galaxies and the Universe ...
... commonly used in all sciences to express mass (kilograms, kg), size (meters, m), and time (seconds, s). It Stars, Galaxies and the Universe ...
On the Spiral Structure of the Milky Way Galaxy
... star formation agree with this concept. The arms traced by HI assume a kneed character in the outer part of the Galaxy, but in general, they continue the flow of the inner arms as they are represented with the four-arm scheme of the Galaxy. ...
... star formation agree with this concept. The arms traced by HI assume a kneed character in the outer part of the Galaxy, but in general, they continue the flow of the inner arms as they are represented with the four-arm scheme of the Galaxy. ...
Hot Horizontal Branch Stars in the Galactic Bulge. I
... in metal-poor systems. Theoretical production of metal-rich sdB’s from single-star evolution can be achieved with a rapid increase at [Fe/H] > 0 in either helium abundance (Bressan, Chiosi, & Fagotto 1994; Yi, Demarque, & Oemler 1998) or mass loss (Dorman, O’Connell, & Rood 1995; D’Cruz et al. 1996) ...
... in metal-poor systems. Theoretical production of metal-rich sdB’s from single-star evolution can be achieved with a rapid increase at [Fe/H] > 0 in either helium abundance (Bressan, Chiosi, & Fagotto 1994; Yi, Demarque, & Oemler 1998) or mass loss (Dorman, O’Connell, & Rood 1995; D’Cruz et al. 1996) ...
Standardized Test Prep Chapter 30 Multiple Choice, continued
... • As gravity makes dense regions within a nebula more compact, these regions spin and shrink and begin to form a flattened disk.The disk has a central concentration of matter called a protostar. • The protostar continues to contract and increase in temperature for several million years. Eventually t ...
... • As gravity makes dense regions within a nebula more compact, these regions spin and shrink and begin to form a flattened disk.The disk has a central concentration of matter called a protostar. • The protostar continues to contract and increase in temperature for several million years. Eventually t ...
Chapter 30 - Todd County Schools
... • As gravity makes dense regions within a nebula more compact, these regions spin and shrink and begin to form a flattened disk.The disk has a central concentration of matter called a protostar. • The protostar continues to contract and increase in temperature for several million years. Eventually t ...
... • As gravity makes dense regions within a nebula more compact, these regions spin and shrink and begin to form a flattened disk.The disk has a central concentration of matter called a protostar. • The protostar continues to contract and increase in temperature for several million years. Eventually t ...
Stellar Populations of Dwarf Elliptical Galaxies: UBVRI Photometry
... velocities are comparable to similar luminosity dwarf irregular galaxies. At the same time, the origin of the non-rotating dwarf ellipticals is unclear. Are these low luminosity galaxies which began with little-to-no angular momentum? Were they formed through the collision of even lower mass galaxie ...
... velocities are comparable to similar luminosity dwarf irregular galaxies. At the same time, the origin of the non-rotating dwarf ellipticals is unclear. Are these low luminosity galaxies which began with little-to-no angular momentum? Were they formed through the collision of even lower mass galaxie ...
Stellar Evolution Nucleosynthesis
... massive enough to fuse some He with C to make oxygen, but most of the C and O will be trapped forever in the white dwarf). • Degeneracy pressure supports the white dwarf against gravity. • White dwarf spend eternity cooling off, eventually going dark entirely. © 2007 Pearson Education Inc., publishi ...
... massive enough to fuse some He with C to make oxygen, but most of the C and O will be trapped forever in the white dwarf). • Degeneracy pressure supports the white dwarf against gravity. • White dwarf spend eternity cooling off, eventually going dark entirely. © 2007 Pearson Education Inc., publishi ...
Formation of cold gas filaments from colliding superbubbles
... stars. This was not an easy observation to interpret. Did stars have a tendency to leave voids in the Universe? As it so ofter happens in science, the explanation was as simple, elegant and exciting as it was surprising and unexpected. These celestial voids turned out to be ”dark clouds”, nebulae wh ...
... stars. This was not an easy observation to interpret. Did stars have a tendency to leave voids in the Universe? As it so ofter happens in science, the explanation was as simple, elegant and exciting as it was surprising and unexpected. These celestial voids turned out to be ”dark clouds”, nebulae wh ...
The Kuiper Belt Explored by Serendipitous Stellar Occultations
... passes through the planet’s atmosphere. The starlight interacts with the atmosphere through refraction and extinction. ...
... passes through the planet’s atmosphere. The starlight interacts with the atmosphere through refraction and extinction. ...
25 Years of the Hubble Space Telescope - Speaker
... Creation” in the Eagle Nebula. This image was the first Hubble image to fascinate the public, and still remains one of Hubble’s most popular images. It was obtained in 1995 with the Wide Field and Planetary Camera 2 (WFPC2). Inside the gaseous towers, which are light-years long, the interstellar gas ...
... Creation” in the Eagle Nebula. This image was the first Hubble image to fascinate the public, and still remains one of Hubble’s most popular images. It was obtained in 1995 with the Wide Field and Planetary Camera 2 (WFPC2). Inside the gaseous towers, which are light-years long, the interstellar gas ...
a wide-field survey for variable stars
... Tauri variable stars. The nearby dusty, yellow cloud is Hind’s Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing ...
... Tauri variable stars. The nearby dusty, yellow cloud is Hind’s Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing ...
Consistent metallicity scale for cool dwarfs and giants
... et al. 2010; Maldonado et al. 2013). Understanding the metallicity distribution of stars with planets would provide an important constraint for planet formation theories. The comparison between the metallicity scale of giants and dwarfs is also important in studies of Galactic chemical evolution. Fo ...
... et al. 2010; Maldonado et al. 2013). Understanding the metallicity distribution of stars with planets would provide an important constraint for planet formation theories. The comparison between the metallicity scale of giants and dwarfs is also important in studies of Galactic chemical evolution. Fo ...
Sparse aperture masking at the VLT II. Detection limits for the eight
... a debris disk, a proto-planetary disk or a planetary system. The understanding of such formation process requires the study of debris disks. These targets are substantial and particularly suitable for optical and infrared observations. Sparse Aperture masking (SAM) is a high angular resolution techn ...
... a debris disk, a proto-planetary disk or a planetary system. The understanding of such formation process requires the study of debris disks. These targets are substantial and particularly suitable for optical and infrared observations. Sparse Aperture masking (SAM) is a high angular resolution techn ...
Chapter 12
... to stars. Parallax is a change in an object’s apparent position caused by a change in the observer’s position. An example—easy to demonstrate in your room—is to hold your hand motionless at arm’s length and shift your head from side to side. Your hand seems to move against the background even though ...
... to stars. Parallax is a change in an object’s apparent position caused by a change in the observer’s position. An example—easy to demonstrate in your room—is to hold your hand motionless at arm’s length and shift your head from side to side. Your hand seems to move against the background even though ...
The presence of gamma rays in space was known before they were
... Black holes are created when especially large suns, around 100 solar masses, collapse in on themselves when they have burnt up all their fuel through fusion. The remains of the core of the sun is so heavy that it collapses beyond the neutron star stage until it becomes an incredibly heavy point, kno ...
... Black holes are created when especially large suns, around 100 solar masses, collapse in on themselves when they have burnt up all their fuel through fusion. The remains of the core of the sun is so heavy that it collapses beyond the neutron star stage until it becomes an incredibly heavy point, kno ...
Astronomy 10
... basic `distance-measuring unit' in the solar system. Make sure that you understand what an astronomical unit is. Seeds gives some measurements using numbers, but it's most important for you to be able to understand it in words, in terms of the distance between the Earth and the Sun. What is the Sol ...
... basic `distance-measuring unit' in the solar system. Make sure that you understand what an astronomical unit is. Seeds gives some measurements using numbers, but it's most important for you to be able to understand it in words, in terms of the distance between the Earth and the Sun. What is the Sol ...
r202 the new astronomy
... way have witnessed another of the great turns in cosmology. We now have evidence for large streaming motions on scales of over 50 Mpc and, possibly of clustering of superclusters on the scales as large as 500 Mpc. We have heard of filaments of galaxies and voids and there is talk of bubbles. Where d ...
... way have witnessed another of the great turns in cosmology. We now have evidence for large streaming motions on scales of over 50 Mpc and, possibly of clustering of superclusters on the scales as large as 500 Mpc. We have heard of filaments of galaxies and voids and there is talk of bubbles. Where d ...
Bonnell_2015_MNRAS_Early - St Andrews Research Repository
... Walch & Naab (2014) investigated the combined influence of photoionization and supernova explosions, building on the work of Walch et al. (2012). They found that the effect of the photoionization phase before the supernova explosion was to delay somewhat the transition of the supernova remnant from ...
... Walch & Naab (2014) investigated the combined influence of photoionization and supernova explosions, building on the work of Walch et al. (2012). They found that the effect of the photoionization phase before the supernova explosion was to delay somewhat the transition of the supernova remnant from ...
Properties of Galactic early-type O
... Aims. We aim to constrain the properties and evolutionary status of early and mid-spectral type supergiants (from O4 to O7.5). These posses the highest mass-loss rates among the O stars, and exhibit conspicuous wind profiles. Methods. Using the non-LTE wind code cmfgen we simultaneously analyzed the ...
... Aims. We aim to constrain the properties and evolutionary status of early and mid-spectral type supergiants (from O4 to O7.5). These posses the highest mass-loss rates among the O stars, and exhibit conspicuous wind profiles. Methods. Using the non-LTE wind code cmfgen we simultaneously analyzed the ...
The old globular cluster system of the dIrr galaxy NGC 1427A in the
... In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxies in the frame of galaxy f ...
... In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxies in the frame of galaxy f ...
PDF - STRW Local - Universiteit Leiden
... While the haloes of dark matter that are thought to host galaxies can be simulated accurately almost from first principles, this is not the case for the galaxies themselves, which consist mostly of baryonic (i.e. ordinary) matter. The difficulties stem from three problems. First, not only gravity, b ...
... While the haloes of dark matter that are thought to host galaxies can be simulated accurately almost from first principles, this is not the case for the galaxies themselves, which consist mostly of baryonic (i.e. ordinary) matter. The difficulties stem from three problems. First, not only gravity, b ...