Dark Matter: Inquiring Minds Want to Know ()
... from things like stars • Can see the light from stars AFTER it has left the star and interacted with whatever is between us and the star ...
... from things like stars • Can see the light from stars AFTER it has left the star and interacted with whatever is between us and the star ...
Curiosities of the Sky
... vast eddy, or system of eddies, whose vortices appear as dark holes. Only a maelstrom-like motion could keep such a funnel open, for without regard to the impulse derived from the projectile, the proper motions of the stars themselves would tend to fill it. Perhaps some other cause of the whirling m ...
... vast eddy, or system of eddies, whose vortices appear as dark holes. Only a maelstrom-like motion could keep such a funnel open, for without regard to the impulse derived from the projectile, the proper motions of the stars themselves would tend to fill it. Perhaps some other cause of the whirling m ...
Exam 2 Solution
... 20.) Lalande 21185 is an M2 red dwarf about 8 LY away and Betelgeuse is an M2 red supergiant about 600 LY away. Both have a temperature of about 3500 K, but we can see Betelgeuse and not Lalande 21185 with the naked eye because… A – Betelgeuse is so much more luminous. B – Betelgeuse has an apparent ...
... 20.) Lalande 21185 is an M2 red dwarf about 8 LY away and Betelgeuse is an M2 red supergiant about 600 LY away. Both have a temperature of about 3500 K, but we can see Betelgeuse and not Lalande 21185 with the naked eye because… A – Betelgeuse is so much more luminous. B – Betelgeuse has an apparent ...
www.esf.org - European Science Foundation
... different environments? Is there a lower limit to the IMF? Can a molecular cloud sustain or not the production of stars for a period of time comparable to its lifetime (>10Myr) and much longer than the typical free-fall time of dense gas (<1Myr)? Currently there is no consensus on the prevalence of ...
... different environments? Is there a lower limit to the IMF? Can a molecular cloud sustain or not the production of stars for a period of time comparable to its lifetime (>10Myr) and much longer than the typical free-fall time of dense gas (<1Myr)? Currently there is no consensus on the prevalence of ...
Binary Stars
... Interactions such as mass exchange / transfer If the smaller (but more massive) star in an IB is a white dwarf, the binary is called a cataclysmic variable ...
... Interactions such as mass exchange / transfer If the smaller (but more massive) star in an IB is a white dwarf, the binary is called a cataclysmic variable ...
The synthesis of organic and inorganic compounds in evolved stars
... burning above an electron-degenerate carbon-oxygen core. For massive (more than ten solar masses, .10 M() stars, direct nuclear burning continues with the production of oxygen, neon, magnesium, silicon and so on, cumulating in the synthesis of iron, the heaviest element possible through direct nucle ...
... burning above an electron-degenerate carbon-oxygen core. For massive (more than ten solar masses, .10 M() stars, direct nuclear burning continues with the production of oxygen, neon, magnesium, silicon and so on, cumulating in the synthesis of iron, the heaviest element possible through direct nucle ...
Nebula
... Some nebulae are formed as the result of supernova explosions, the death throes of massive, short-lived stars. The material thrown off from the supernova explosion is ionised by the supernova remnant. One of the best examples of this is the Crab Nebula, in Taurus. It is the result of a recorded sup ...
... Some nebulae are formed as the result of supernova explosions, the death throes of massive, short-lived stars. The material thrown off from the supernova explosion is ionised by the supernova remnant. One of the best examples of this is the Crab Nebula, in Taurus. It is the result of a recorded sup ...
Project 5: Globular cluster
... A globular cluster is a spherical collection of stars that are very tightly bound to each other by gravity. Globular clusters orbit around the Milky Way galaxy core like satellites. The number of stars in a globular cluster varies from a few thousand up to a million stars for the m ...
... A globular cluster is a spherical collection of stars that are very tightly bound to each other by gravity. Globular clusters orbit around the Milky Way galaxy core like satellites. The number of stars in a globular cluster varies from a few thousand up to a million stars for the m ...
Search for giant planets in M67 - III. Excess of hot Jupiters in dense
... Hot Jupiters (HJs) are defined as giant planets (Mp > 0.3MJup ) on short-period orbits (P < 10 days). They show an occurrance rate of ∼1.2% around Sun-like field stars (Wright et al. 2012; Mayor et al. 2011). These close-in giant planets are highly unlikely to have formed in situ, and it is believed ...
... Hot Jupiters (HJs) are defined as giant planets (Mp > 0.3MJup ) on short-period orbits (P < 10 days). They show an occurrance rate of ∼1.2% around Sun-like field stars (Wright et al. 2012; Mayor et al. 2011). These close-in giant planets are highly unlikely to have formed in situ, and it is believed ...
Constraints on the Production of Ultra–High
... spall into lighter elements, probably hydrogen and helium (Bildsten, Salpeter, & Wasserman 1992). However, for much of the fallback the temperature on the surface is at least ...
... spall into lighter elements, probably hydrogen and helium (Bildsten, Salpeter, & Wasserman 1992). However, for much of the fallback the temperature on the surface is at least ...
Is $^ 6$ Li in metal-poor halo stars produced in situ by solar
... It has been known for many years that the chromospheric and coronal activities of dwarf stars are closely related to their rotation (Kraft 1967). This relationship results from the generation and amplification of surface magnetic fields by a complex dynamo mechanism, whose efficiency depends on the in ...
... It has been known for many years that the chromospheric and coronal activities of dwarf stars are closely related to their rotation (Kraft 1967). This relationship results from the generation and amplification of surface magnetic fields by a complex dynamo mechanism, whose efficiency depends on the in ...
ISA_lecture01 - School of Physics
... (c) has cleared the neighbourhood around its orbit. A “dwarf planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) ...
... (c) has cleared the neighbourhood around its orbit. A “dwarf planet” is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) ...
Magnitudes lesson plan
... magnitude six, and the other visible stars were arbitrarily placed between magnitudes one and six according to their apparent brightness. Apparent Magnitude refers to the apparent brightness of one star relative to another as seen with the unaided eye. Keep in mind this refers to the apparent bright ...
... magnitude six, and the other visible stars were arbitrarily placed between magnitudes one and six according to their apparent brightness. Apparent Magnitude refers to the apparent brightness of one star relative to another as seen with the unaided eye. Keep in mind this refers to the apparent bright ...
Carbon monoxide in clouds at low metallicity in the dwarf irregular
... Carbon monoxide (CO) is the primary tracer for interstellar clouds where stars form, but it has never been detected in galaxies in which the oxygen abundance relative to hydrogen is less than 20 per cent of that of the Sun, even though such ‘low-metallicity’ galaxies often form stars. This raises th ...
... Carbon monoxide (CO) is the primary tracer for interstellar clouds where stars form, but it has never been detected in galaxies in which the oxygen abundance relative to hydrogen is less than 20 per cent of that of the Sun, even though such ‘low-metallicity’ galaxies often form stars. This raises th ...
1 Astrobiologically Interesting Stars within 10
... disrupted. Masses larger than 1.20 solar may remain acceptable if allowance is made for a faster evolution of complex life than was the case on Earth. Yet, besides these well-accepted notions, quite a few other considerations have recently been increasingly considered as playing fundamental roles fo ...
... disrupted. Masses larger than 1.20 solar may remain acceptable if allowance is made for a faster evolution of complex life than was the case on Earth. Yet, besides these well-accepted notions, quite a few other considerations have recently been increasingly considered as playing fundamental roles fo ...
– 1 – 1. Feedback From The First Stars
... into the halo gas may produce shocks, and strong outflows. These shocks may then become sites for additional subsequent star formation, while if the gas is heated and dispersed, star formation will be halted. Evidence for large scale outflows (“galactic winds”) in local group starbursting dwarfs has ...
... into the halo gas may produce shocks, and strong outflows. These shocks may then become sites for additional subsequent star formation, while if the gas is heated and dispersed, star formation will be halted. Evidence for large scale outflows (“galactic winds”) in local group starbursting dwarfs has ...
Document
... These sources can contribute both to the population of unidentified point-like sources and to the local cosmic-ray electron spectrum. The inverse Compton emission of these locally generated cosmic rays may explain the variety of gamma-ray spectra detected from nearby molecular clouds. ...
... These sources can contribute both to the population of unidentified point-like sources and to the local cosmic-ray electron spectrum. The inverse Compton emission of these locally generated cosmic rays may explain the variety of gamma-ray spectra detected from nearby molecular clouds. ...
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.