REVIEWS The formation of the first stars and galaxies Volker Bromm
... Observations made using large ground-based and space-borne telescopes have probed cosmic history from the present day to a time when the Universe was less than one-tenth of its present age. Earlier still lies the remaining frontier, where the first stars, galaxies and massive black holes formed. The ...
... Observations made using large ground-based and space-borne telescopes have probed cosmic history from the present day to a time when the Universe was less than one-tenth of its present age. Earlier still lies the remaining frontier, where the first stars, galaxies and massive black holes formed. The ...
Asteroseismic constraints on Asymmetric Dark Matter: Light particles
... constrained by photometric and spectroscopic observations. Within that subset, the best candidates are those for which astrometric observations are also available, for example stars observed by both Kepler and Hipparcos [52]. Thus, the ideal candidate is an object with highly constrained fundamental ...
... constrained by photometric and spectroscopic observations. Within that subset, the best candidates are those for which astrometric observations are also available, for example stars observed by both Kepler and Hipparcos [52]. Thus, the ideal candidate is an object with highly constrained fundamental ...
plato
... • Identification and characterisation of planetary systems - including planets of all masses and sizes on various orbits - around stars of all types and ages - including seismic characterization of planet host stars - in particular rocky planets in habitable zone of solar-like stars ...
... • Identification and characterisation of planetary systems - including planets of all masses and sizes on various orbits - around stars of all types and ages - including seismic characterization of planet host stars - in particular rocky planets in habitable zone of solar-like stars ...
Planet formation around M-dwarfs: the moving snow line and super
... To reach isolation, protoplanets must overcome type I migration, where the object is torqued by density waves excited in the gas disk (e.g. Tanaka et al. 2002). Type I migration timescales are typically very short—of the order 104 yr for the Jovian core. Icy protoplanets in general may suffer simila ...
... To reach isolation, protoplanets must overcome type I migration, where the object is torqued by density waves excited in the gas disk (e.g. Tanaka et al. 2002). Type I migration timescales are typically very short—of the order 104 yr for the Jovian core. Icy protoplanets in general may suffer simila ...
Document
... S(E) is a slowly varying function determined by the nuclear physics of the reaction 1/E introduced to account for low energy behaviour ...
... S(E) is a slowly varying function determined by the nuclear physics of the reaction 1/E introduced to account for low energy behaviour ...
NATS 1311 From the Cosmos to Earth
... Its inert helium core contracts while hydrogen fusion in a shell outside the core begins. The high rate of fusion in the hydrogen shell forces the star's upper layers to expand outward causing the star to expand greatly in size, moving location on HR diagram up and to the right to the giant region. ...
... Its inert helium core contracts while hydrogen fusion in a shell outside the core begins. The high rate of fusion in the hydrogen shell forces the star's upper layers to expand outward causing the star to expand greatly in size, moving location on HR diagram up and to the right to the giant region. ...
Energy transport in stellar interiors
... Energy transport in stellar interiors The energy that a star radiates from its surface is generally replenished from sources or reservoirs located in its hot central region. We have seen that most stars are in a long-lived state of thermal equilibrium, in which these terms exactly balance. What woul ...
... Energy transport in stellar interiors The energy that a star radiates from its surface is generally replenished from sources or reservoirs located in its hot central region. We have seen that most stars are in a long-lived state of thermal equilibrium, in which these terms exactly balance. What woul ...
a report on pulsars, written for PHAS1901
... dependence on frequency, v, given by L ∝ where ~0.75 . Since v > 1 and β < 1, as v increases, vβ will increase and v-β will decrease. this means that signal strength of pulses will be higher when observed at lower frequencies. Due to the fact that each pulse detected on the earth will correspond ...
... dependence on frequency, v, given by L ∝ where ~0.75 . Since v > 1 and β < 1, as v increases, vβ will increase and v-β will decrease. this means that signal strength of pulses will be higher when observed at lower frequencies. Due to the fact that each pulse detected on the earth will correspond ...
Distances to the Hyades Cluster
... this method; to summarize the significant results obtained by the Hipparchos satellite and what these results mean for the distance scale of the Universe. Background and Theory The zero-point for the entire cosmic distance scale, out to the farthest reaches of the observable universe, has been based ...
... this method; to summarize the significant results obtained by the Hipparchos satellite and what these results mean for the distance scale of the Universe. Background and Theory The zero-point for the entire cosmic distance scale, out to the farthest reaches of the observable universe, has been based ...
Exploring Space—The Universe: The Vast
... Q: What will happen to the sun after its supply of hydrogen is nearly used up? A: Over the course of billions of years, the helium core of the sun will begin to shrink, and the helium atoms will fuse to form carbon atoms. The sun’s hydrogen outer shell will expand until the sun becomes a red giant, ...
... Q: What will happen to the sun after its supply of hydrogen is nearly used up? A: Over the course of billions of years, the helium core of the sun will begin to shrink, and the helium atoms will fuse to form carbon atoms. The sun’s hydrogen outer shell will expand until the sun becomes a red giant, ...
Observational properties of stars
... location goes to shorter (smaller) wavelength, or it would also go to higher frequency. Therefore “hot” objects are blue while “cool” objects are red. It is also worth noting that even though you can’t see it, black body energy is given off at all wavelengths, from those close to =0 to the longest w ...
... location goes to shorter (smaller) wavelength, or it would also go to higher frequency. Therefore “hot” objects are blue while “cool” objects are red. It is also worth noting that even though you can’t see it, black body energy is given off at all wavelengths, from those close to =0 to the longest w ...
Lecture 24 Early Universe
... In particle physics, quarks are one of the two basic constituents of matter (the other Standard Model fermions are the leptons). Antiparticles of quarks are called antiquarks. Quarks are the only fundamental particles that interact through all four of the fundamental forces. The word was borrowed by ...
... In particle physics, quarks are one of the two basic constituents of matter (the other Standard Model fermions are the leptons). Antiparticles of quarks are called antiquarks. Quarks are the only fundamental particles that interact through all four of the fundamental forces. The word was borrowed by ...
Chapter 25 - Haiku Learning
... mass. The hottest blue stars are about 50 times more massive than the sun, while the coolest red stars are only 1/10 as massive. Therefore, on the H-R diagram, the main-sequence stars appear in decreasing order, from hotter, more massive blue stars to cooler, less massive red stars. Above and to the ...
... mass. The hottest blue stars are about 50 times more massive than the sun, while the coolest red stars are only 1/10 as massive. Therefore, on the H-R diagram, the main-sequence stars appear in decreasing order, from hotter, more massive blue stars to cooler, less massive red stars. Above and to the ...
Astronomy Report Southern Cross Authors Maria Constanza Pavez
... as a nova or supernova, and then evolving to be a white dwarf or a neutron star, eventually becoming a pulsar. On the other hand, we must take notice of the fact that neutron star has an inferior size limit, so it could become a black hole (region of the space with such a high density that no radiat ...
... as a nova or supernova, and then evolving to be a white dwarf or a neutron star, eventually becoming a pulsar. On the other hand, we must take notice of the fact that neutron star has an inferior size limit, so it could become a black hole (region of the space with such a high density that no radiat ...
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.