Determining the Stellar Spin Axis Orientation
... the displacement caused by the instrumental profile from the one generated by the stellar rotation requires a special observing technique and additional instrument. We have developed a differential image rotator, a small instrument to be inserted between the telescope output and the slit, which spli ...
... the displacement caused by the instrumental profile from the one generated by the stellar rotation requires a special observing technique and additional instrument. We have developed a differential image rotator, a small instrument to be inserted between the telescope output and the slit, which spli ...
Dark Matter NS Warsaw
... ▸ Since the dark matter density near the Galactic center is significantly higher than regions near the solar position (where the oldest pulsars have been found) there is a parameter space where dark matter accumulation may solve the missing pulsar problem. ...
... ▸ Since the dark matter density near the Galactic center is significantly higher than regions near the solar position (where the oldest pulsars have been found) there is a parameter space where dark matter accumulation may solve the missing pulsar problem. ...
sections 16-18 instructor notes
... in the direction of the Galactic centre. The results depend upon the assumption that all such stars are bound to the Galaxy and that their orbits are governed by the mass of the Galaxy concentrated inside the solar circle. The implied value of 0 is between 275 and 300 km/s with the last assumption, ...
... in the direction of the Galactic centre. The results depend upon the assumption that all such stars are bound to the Galaxy and that their orbits are governed by the mass of the Galaxy concentrated inside the solar circle. The implied value of 0 is between 275 and 300 km/s with the last assumption, ...
Document
... This also means that if you know the distance to a star (d), and the apparent magnitude (which you can measure by the size of an image on a photograph), then you can use this equation to find distance... Example if you are intersted. Star A has a magnitude of 5 and an absolte magnitude of 12. Thus: ...
... This also means that if you know the distance to a star (d), and the apparent magnitude (which you can measure by the size of an image on a photograph), then you can use this equation to find distance... Example if you are intersted. Star A has a magnitude of 5 and an absolte magnitude of 12. Thus: ...
The evolution of Red Supergiants to supernova in the LMC cluster
... part, provide a solution to the missing high mass RSG progenitors. It is known that RSG form dust in their winds (e.g de Wit et al. 2008) and infrared interferometry has shown that this dust can lie very close to the star itself (Danchi et al. 1994). Walmswell & Eldridge (2012) have shown that by fa ...
... part, provide a solution to the missing high mass RSG progenitors. It is known that RSG form dust in their winds (e.g de Wit et al. 2008) and infrared interferometry has shown that this dust can lie very close to the star itself (Danchi et al. 1994). Walmswell & Eldridge (2012) have shown that by fa ...
Journey through the cosmos
... When you look at the night sky, you can see only about three thousand stars of our own Galaxy with the naked eye. The darker the skies, the more stars you can see. Of course, there are billions more stars but they are so far away. You can see stars because they are luminous, which means that they gi ...
... When you look at the night sky, you can see only about three thousand stars of our own Galaxy with the naked eye. The darker the skies, the more stars you can see. Of course, there are billions more stars but they are so far away. You can see stars because they are luminous, which means that they gi ...
Astronomy Astrophysics A VLT/FLAMES survey for massive binaries in Westerlund 1 &
... Sects. 2.3 and 3.1 one might expect any reflex motion in a putative early type companion to be of low amplitude, such that it would be difficult to identify at the resolution of these data. A28, page 3 of 10 ...
... Sects. 2.3 and 3.1 one might expect any reflex motion in a putative early type companion to be of low amplitude, such that it would be difficult to identify at the resolution of these data. A28, page 3 of 10 ...
Document
... abundance in the star and thus the proto-planetary disk. A higher metal content implies that the planets are easier to form (core accretion theory) → the high metal abundance forms more planets Scenario 2: The high metal content is only on the surface layers of the star and result from the accretion ...
... abundance in the star and thus the proto-planetary disk. A higher metal content implies that the planets are easier to form (core accretion theory) → the high metal abundance forms more planets Scenario 2: The high metal content is only on the surface layers of the star and result from the accretion ...
Test#4
... c) fairly uniform, d) has remained the same as it was during the big bang 7. The location of our Sun in the galaxy is approximately a) near the core, b) near the outer edge c) about 2/3 of the way out to the edge, d) not currently determined 8. About how long does it take for the Sun to complete one ...
... c) fairly uniform, d) has remained the same as it was during the big bang 7. The location of our Sun in the galaxy is approximately a) near the core, b) near the outer edge c) about 2/3 of the way out to the edge, d) not currently determined 8. About how long does it take for the Sun to complete one ...
Optical studies of an ultraluminous X-ray source: NGC1313 X-2 Jifeng Liu
... • a barred SB(s)d galaxy at 3.7Mpc • low metallicity of 0.1-0.2 Zs • irregular SW satellite regions - a tidally disrupted companion galaxy? a collision of huge HI clouds with the disk? ...
... • a barred SB(s)d galaxy at 3.7Mpc • low metallicity of 0.1-0.2 Zs • irregular SW satellite regions - a tidally disrupted companion galaxy? a collision of huge HI clouds with the disk? ...
Upcoming Events
... light from galaxies originates from nebulae like this one. But its great luminosity and relative proximity makes it easy to overlook the fact that there are a slew of much closer star-forming regions than the Orion Nebula; they're just much, much fainter. If you get a collapsing molecular cloud many ...
... light from galaxies originates from nebulae like this one. But its great luminosity and relative proximity makes it easy to overlook the fact that there are a slew of much closer star-forming regions than the Orion Nebula; they're just much, much fainter. If you get a collapsing molecular cloud many ...
Notes for Class 7, March 2
... o So far, too close to star, too hot o If planets around other stars are common, maybe there will be some planets with the right conditions, and maybe some of them will have life ...
... o So far, too close to star, too hot o If planets around other stars are common, maybe there will be some planets with the right conditions, and maybe some of them will have life ...
Red supergiants and the past of Cygnus OB2
... have already evolved away from the main sequence and that the main star-forming sites have been shifting with time. The study of this older component is made difficult by the effects of stellar evolution, and in particular by the fact that its most massive components have already disappeared as supe ...
... have already evolved away from the main sequence and that the main star-forming sites have been shifting with time. The study of this older component is made difficult by the effects of stellar evolution, and in particular by the fact that its most massive components have already disappeared as supe ...
Chapter 21 - apel slice
... radiation. Telescopes make distant objects appear larger and brighter. A telescope that uses lenses or mirrors to collect and focus visible light is called an optical telescope. The two major types of optical telescope are refracting telescopes and reflecting telescopes. Modern astronomy is based on ...
... radiation. Telescopes make distant objects appear larger and brighter. A telescope that uses lenses or mirrors to collect and focus visible light is called an optical telescope. The two major types of optical telescope are refracting telescopes and reflecting telescopes. Modern astronomy is based on ...
Power-point slides for Lecture 1
... Note that this makes the supernova luminosity at peak a function of a single parameter – e.g., the width. ...
... Note that this makes the supernova luminosity at peak a function of a single parameter – e.g., the width. ...
The Milky Way Galaxy - d_smith.lhseducators.com
... Milky Way’s Structure Nuclear Bulge in center – 12,000 LY wide x 10,000 LY thick – Made of old (mostly yellow & red) stars – Contains much of the visible mass in the galaxy. ...
... Milky Way’s Structure Nuclear Bulge in center – 12,000 LY wide x 10,000 LY thick – Made of old (mostly yellow & red) stars – Contains much of the visible mass in the galaxy. ...
arXiv:astro-ph/0612072v1 4 Dec 2006 Theory of core
... The core bounce with the formation of a shock wave is the starting point of a sequence of events that ultimately triggers a supernova explosion (Fig. 1, middle left panel), but the exact mechanism of the explosion and the crucial ingredients of this physically appealing scenario are still uncertain ...
... The core bounce with the formation of a shock wave is the starting point of a sequence of events that ultimately triggers a supernova explosion (Fig. 1, middle left panel), but the exact mechanism of the explosion and the crucial ingredients of this physically appealing scenario are still uncertain ...
Yellow supergiants as supernova progenitors: an indication of
... a factor of ten, the same trend is observed, but much stronger. In that case, the surface H abundance is strongly depleted, becoming smaller than the He abundance. Measurements of the surface abundances indicating such trends would be a clue to strong mass loss during the RSG phase. As three of the ...
... a factor of ten, the same trend is observed, but much stronger. In that case, the surface H abundance is strongly depleted, becoming smaller than the He abundance. Measurements of the surface abundances indicating such trends would be a clue to strong mass loss during the RSG phase. As three of the ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.