Investigating the Spectral Energy Distribution TARA JILL PARKIN
... In particular, the present-day structure of the ISM of a galaxy is strongly dependent on the evolution of its star formation rate (SFR). Clues as to previous episodes of star formation rates can be found in the various stellar populations within the galaxy (Tielens, 1995). Low-mass stars with long l ...
... In particular, the present-day structure of the ISM of a galaxy is strongly dependent on the evolution of its star formation rate (SFR). Clues as to previous episodes of star formation rates can be found in the various stellar populations within the galaxy (Tielens, 1995). Low-mass stars with long l ...
Published in Contemp. Phys. 51, 464-465 (2010).
... in the southern sky? This too seems improbable, as the scattering would simultaneously have dimmed Sirius to the point where it would have seemed uninteresting. Yet another possibility arises from the fact that Sirius is a double star: Sirius A has a companion white dwarf star Sirius B. Suppose Siri ...
... in the southern sky? This too seems improbable, as the scattering would simultaneously have dimmed Sirius to the point where it would have seemed uninteresting. Yet another possibility arises from the fact that Sirius is a double star: Sirius A has a companion white dwarf star Sirius B. Suppose Siri ...
Planetary Nebula
... the central star is so prominent, the original thinking on this nebula’s formation focused around the central star itself. But the motions of the gas are also being observed and a recent study suggest that some of the structures observed are caused by the interaction of central star wind and radiati ...
... the central star is so prominent, the original thinking on this nebula’s formation focused around the central star itself. But the motions of the gas are also being observed and a recent study suggest that some of the structures observed are caused by the interaction of central star wind and radiati ...
What causes the large extensions of red supergiant
... Heger 1999). Constraints on the mechanisms that levitate the atmospheres of RSGs are thus fundamental for our understanding of the mass-loss process of RSG stars. Observations of Mira variable stars using the IOTA or VLTI interferometers show evidence of molecular layers lying above the photospheric ...
... Heger 1999). Constraints on the mechanisms that levitate the atmospheres of RSGs are thus fundamental for our understanding of the mass-loss process of RSG stars. Observations of Mira variable stars using the IOTA or VLTI interferometers show evidence of molecular layers lying above the photospheric ...
Leaky Stars: Pulsations, Waves, and Turbulence in Stellar Winds
... disk photons, “Doppler dimming/pumping” occurs. Leaky Stars: Pulsations, Waves, and Turbulence in Stellar Winds across the H-R Diagram ...
... disk photons, “Doppler dimming/pumping” occurs. Leaky Stars: Pulsations, Waves, and Turbulence in Stellar Winds across the H-R Diagram ...
The masses and spins of neutron stars and stellar
... As the remnants of core-collapse supernovae, neutron stars and black holes are also windows into the collapse and explosion processes. The further evolution of these systems in accreting binaries can tell us about the accretion process, e.g., the total amount of mass that is typically deposited on t ...
... As the remnants of core-collapse supernovae, neutron stars and black holes are also windows into the collapse and explosion processes. The further evolution of these systems in accreting binaries can tell us about the accretion process, e.g., the total amount of mass that is typically deposited on t ...
The extended structure of the dwarf irregular galaxies Sextans A and
... previously traced with surface photometry, out to ∼ 4 kpc from their centres along their major axes. Older stars are found to have more extended distribution than younger populations. We obtain the first estimate of the mean metallicity for the old stars in Sex B, from the colour distribution of the ...
... previously traced with surface photometry, out to ∼ 4 kpc from their centres along their major axes. Older stars are found to have more extended distribution than younger populations. We obtain the first estimate of the mean metallicity for the old stars in Sex B, from the colour distribution of the ...
ExoPlanet News No. 74, November 3rd, 2014 Contents An Electronic Newsletter
... UT4 VLT and Keck telescopes. Radial velocity measurements of J1407 provide additional constraints on J1407b and on short period companions to the central star. Follow-up photometric monitoring using the PROMPT-4 and ROAD observatories during 2012-2014 has not yielded any additional eclipses. Large r ...
... UT4 VLT and Keck telescopes. Radial velocity measurements of J1407 provide additional constraints on J1407b and on short period companions to the central star. Follow-up photometric monitoring using the PROMPT-4 and ROAD observatories during 2012-2014 has not yielded any additional eclipses. Large r ...
The physics and modes of star cluster formation: observations
... hindered by the fact that open clusters are born in molecular clouds and, during their formation and early evolution, are completely embedded in molecular gas and dust. They are thus obscured from view at optical wavelengths, where the traditional astronomical techniques are most effective. Fortunat ...
... hindered by the fact that open clusters are born in molecular clouds and, during their formation and early evolution, are completely embedded in molecular gas and dust. They are thus obscured from view at optical wavelengths, where the traditional astronomical techniques are most effective. Fortunat ...
Sample syllabus 2 - Johns Hopkins Center for Talented Youth
... Course Description: When the sun runs out of fuel, will it explode in a giant supernova or fade out into a white dwarf? Does every galaxy revolve around a super-massive black hole? Will the universe continue to expand, or will it eventually collapse back upon itself in a reversal of the Big Bang? As ...
... Course Description: When the sun runs out of fuel, will it explode in a giant supernova or fade out into a white dwarf? Does every galaxy revolve around a super-massive black hole? Will the universe continue to expand, or will it eventually collapse back upon itself in a reversal of the Big Bang? As ...
Chapter 15 Stars, Galaxies and Universe
... of stars. The H-R diagram is a graph that shows the relationship between the star’s surface temperature and absolute magnitude. • The stages of a star’s life cycle and its properties at each stage can be plotted on an H-R diagram. ...
... of stars. The H-R diagram is a graph that shows the relationship between the star’s surface temperature and absolute magnitude. • The stages of a star’s life cycle and its properties at each stage can be plotted on an H-R diagram. ...
Origin and formation of planetary systems
... can form Jupiter-mass clumps, even in a disk with a mass of about 0.091 MSun within 20 AU. This mass is low enough to be in the range inferred for the solar nebula. The clumps form with initially eccentric orbits, and their survival will depend on their ability to contract to higher densities before ...
... can form Jupiter-mass clumps, even in a disk with a mass of about 0.091 MSun within 20 AU. This mass is low enough to be in the range inferred for the solar nebula. The clumps form with initially eccentric orbits, and their survival will depend on their ability to contract to higher densities before ...
SPIRou Science Case
... decided in 2014), TESS/NASA, CHEOPS/ESA, ExTrA 1 and PLATO/ESA (after being launched in 2024) to identify the true planets among the candidates they will discover. The second main goal is to explore the impact of magnetic fields on star & planet formation, by detecting fields of various types of you ...
... decided in 2014), TESS/NASA, CHEOPS/ESA, ExTrA 1 and PLATO/ESA (after being launched in 2024) to identify the true planets among the candidates they will discover. The second main goal is to explore the impact of magnetic fields on star & planet formation, by detecting fields of various types of you ...
A SPECTROSCOPIC STUDY OF A LARGE SAMPLE OF WOLF-RAYET GALAXIES
... hence cannot be distinguished from other WR stars in low-resolution spectra. Additionally, WNE stars are not as luminous as WNL stars in the optical range. The WR star lifetime in the WNE stage is short compared to that in the WNL stage for nearly all metallicities and progenitor star masses (Maeder ...
... hence cannot be distinguished from other WR stars in low-resolution spectra. Additionally, WNE stars are not as luminous as WNL stars in the optical range. The WR star lifetime in the WNE stage is short compared to that in the WNL stage for nearly all metallicities and progenitor star masses (Maeder ...
An Optical Study of Young Stellar Clusters
... Together with the time modulation of the star formation process, known as the star formation rate, it dictates the evolution and fate of stellar systems up to entire galaxies. The vast majority of stars are not formed in isolation, but as part of stellar associations and clusters (Lada & Lada, 2003) ...
... Together with the time modulation of the star formation process, known as the star formation rate, it dictates the evolution and fate of stellar systems up to entire galaxies. The vast majority of stars are not formed in isolation, but as part of stellar associations and clusters (Lada & Lada, 2003) ...
The AG Carinae nebula: abundant evidence for a red supergiant
... AG Carinae is a massive, evolved supergiant which is thought to be in transition from an 0 star to a Wolf-Rayet (WR) star and is currently identified as a luminous blue variable (LBV) with 10gLlL0 = 6.0. We present an abundance study of the ejecta nebula surrounding AG Car with the aim of elucidatin ...
... AG Carinae is a massive, evolved supergiant which is thought to be in transition from an 0 star to a Wolf-Rayet (WR) star and is currently identified as a luminous blue variable (LBV) with 10gLlL0 = 6.0. We present an abundance study of the ejecta nebula surrounding AG Car with the aim of elucidatin ...
Reassessing the formation of the inner Oort cloud
... system consisting of stars, planets and comets is treated self-consistently in our N-body simulations, rather than approximating the stellar encounters with the outer Solar System as hyperbolic fly-bys. Second, we have included the expulsion of the cluster gas, a feature that was absent previously. ...
... system consisting of stars, planets and comets is treated self-consistently in our N-body simulations, rather than approximating the stellar encounters with the outer Solar System as hyperbolic fly-bys. Second, we have included the expulsion of the cluster gas, a feature that was absent previously. ...
The Development of Constructed Response Astronomy Assessment
... a discussion of whether the emission is produced by a nebula, star, planet or other class of object falls in the the astrophysical system category, while the “density” bin covering mentions of the density of the source media is of the physical property type. The original LSCI multiple choice answers ...
... a discussion of whether the emission is produced by a nebula, star, planet or other class of object falls in the the astrophysical system category, while the “density” bin covering mentions of the density of the source media is of the physical property type. The original LSCI multiple choice answers ...
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.