6th Grade The Theoretical Beginning of the Universe / Big Bang
... Just like with many ideas in Science, there are people who are critical of the Big Bang. The idea that there was a "Big Bang" is a theory . This means that it can not completely be assumed to be fact, but it has not yet been ...
... Just like with many ideas in Science, there are people who are critical of the Big Bang. The idea that there was a "Big Bang" is a theory . This means that it can not completely be assumed to be fact, but it has not yet been ...
Presentation on the universe
... younger... but we need to come up with adefinition more correct forare Gravity. Click on Sir Isaac Newton, who first wrote about the theory of gravity, to discover our more complete definition. ...
... younger... but we need to come up with adefinition more correct forare Gravity. Click on Sir Isaac Newton, who first wrote about the theory of gravity, to discover our more complete definition. ...
Article PDF - IOPscience
... wide range of colors (and include RR Lyrae variables), Fornax 4 is seen to have a red horizontal branch. Fornax 4 is D3 Gyr younger than the other Fornax globulars. Buonanno et al. draw attention to the fact that the colormagnitude diagram of Fornax 4 exhibits a strong resemblance to that of the ““ ...
... wide range of colors (and include RR Lyrae variables), Fornax 4 is seen to have a red horizontal branch. Fornax 4 is D3 Gyr younger than the other Fornax globulars. Buonanno et al. draw attention to the fact that the colormagnitude diagram of Fornax 4 exhibits a strong resemblance to that of the ““ ...
Resources: - Real Science
... extending theories that explain other neutron stars: The magnetic fields inside the neutron star are probably wound up, like a twisted spring. As the magnetic fields unwind they create stresses in the outer crust, rather like the stresses created by plate tectonics on Earth. The crust would resist t ...
... extending theories that explain other neutron stars: The magnetic fields inside the neutron star are probably wound up, like a twisted spring. As the magnetic fields unwind they create stresses in the outer crust, rather like the stresses created by plate tectonics on Earth. The crust would resist t ...
Ultraluminous X-ray Sources in Andromeda Galaxy
... is not yet established with certainty. In particular, whether or not the accretion is super/sub Eddington is an open question, as is the mass of the companion star. We discuss the first two ULXs recently discovered in M31 and investigate the nature of their underlying sources. We present the X-ray o ...
... is not yet established with certainty. In particular, whether or not the accretion is super/sub Eddington is an open question, as is the mass of the companion star. We discuss the first two ULXs recently discovered in M31 and investigate the nature of their underlying sources. We present the X-ray o ...
A" Light," Centrally-Concentrated Milky Way Halo?
... To proceed further, we have assumed a scale-free density profile for the stellar tracers, ρ∗ ∝ r−γ , and numerically integrated the equation above by taking Eris’ underlying gravity field and multiplying the mass inside some radius r by a factor of 2.5. The last step is meant to mimic the potential ...
... To proceed further, we have assumed a scale-free density profile for the stellar tracers, ρ∗ ∝ r−γ , and numerically integrated the equation above by taking Eris’ underlying gravity field and multiplying the mass inside some radius r by a factor of 2.5. The last step is meant to mimic the potential ...
Starspots: A Key to the Stellar Dynamo | SpringerLink
... 0.2 R to about 0.6 R while their effective temperatures are in the range of 2500 K – 4000 K. Thus, red dwarf stars are cooler, smaller, and less massive than the Sun. Correspondingly their luminosities range from 0.1% to about 8% of the solar luminosity. They constitute, at least, 80% of the stell ...
... 0.2 R to about 0.6 R while their effective temperatures are in the range of 2500 K – 4000 K. Thus, red dwarf stars are cooler, smaller, and less massive than the Sun. Correspondingly their luminosities range from 0.1% to about 8% of the solar luminosity. They constitute, at least, 80% of the stell ...
Comparing molecular gas across cosmic time
... sity, and hence objects situated above the relation are either supervirial, or have a gravitational potential that is not gas-dominated. The main sub-samples that deviate from the relation are the nearby spiral galaxies, the CMZ regions, and the high-z galaxies. For the spiral galaxies, this is easi ...
... sity, and hence objects situated above the relation are either supervirial, or have a gravitational potential that is not gas-dominated. The main sub-samples that deviate from the relation are the nearby spiral galaxies, the CMZ regions, and the high-z galaxies. For the spiral galaxies, this is easi ...
Astronomy Astrophysics IRAS 18357-0604 – an analogue of the galactic yellow hypergiant
... Context. Yellow hypergiants represent a short-lived evolutionary episode experienced by massive stars as they transit to and from a red supergiant phase. As such, their properties provide a critical test of stellar evolutionary theory, while recent observations unexpectedly suggest that a subset may ...
... Context. Yellow hypergiants represent a short-lived evolutionary episode experienced by massive stars as they transit to and from a red supergiant phase. As such, their properties provide a critical test of stellar evolutionary theory, while recent observations unexpectedly suggest that a subset may ...
Neutron Stars in Compact Binary Systems: From the equation of
... nuclear fusion reactions radiate energy outward, supplying enough pressure to keep the star at the size we see. Eventually, however, the raw materials in the core are used up. The fusion halts, and the outward pressure drops. Without this pressure, the core collapses in on itself until something els ...
... nuclear fusion reactions radiate energy outward, supplying enough pressure to keep the star at the size we see. Eventually, however, the raw materials in the core are used up. The fusion halts, and the outward pressure drops. Without this pressure, the core collapses in on itself until something els ...
NEAR-INFRARED THERMAL EMISSION FROM THE HOT JUPITER
... normalized sky frame built by taking the median of a stack of source-masked and background-normalized on-sky images. Our on-sky images consist of 15 dithered in-focus images observed before and after the on-target sequence. For each on-target image the normalized sky frame is scaled to the target me ...
... normalized sky frame built by taking the median of a stack of source-masked and background-normalized on-sky images. Our on-sky images consist of 15 dithered in-focus images observed before and after the on-target sequence. For each on-target image the normalized sky frame is scaled to the target me ...
Reconciling Dwarf Galaxies with LCDM Cosmology Andrew Wetzel F RE
... fiducial choice, an α = 0.18 Eina all resolved haloes with V ...
... fiducial choice, an α = 0.18 Eina all resolved haloes with V ...
and galaxies
... stars were surrounded by dust shells which heat up and subsequently re-radiate in the infra-red region. Although these spectra are generally continuous, for some stars, an extra continuous peak was superimposed on the usual black body spectrum at wavelengths of approx. 10,000 nm. This was consistent ...
... stars were surrounded by dust shells which heat up and subsequently re-radiate in the infra-red region. Although these spectra are generally continuous, for some stars, an extra continuous peak was superimposed on the usual black body spectrum at wavelengths of approx. 10,000 nm. This was consistent ...
Hewitt/Lyons/Suchocki/Yeh, Conceptual Integrated Science
... none of its terms differ. Although the density of the black hole has greatly increased, its mass is the same before and after collapse. Because the mass of Earth and the solar black hole are the same, and distance between centers is the same, the force holding Earth in orbit wouldn’t ...
... none of its terms differ. Although the density of the black hole has greatly increased, its mass is the same before and after collapse. Because the mass of Earth and the solar black hole are the same, and distance between centers is the same, the force holding Earth in orbit wouldn’t ...
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.