astronomy
... sky looked blue, like a great body of water overhead. Their conclusion was that the Sun god, Ra, sailed from east to west each day in a boat of fire. He then disappeared into the underworld until the next morning. It is likely that even the earliest nomadic people used the patterns of the Sun, Moon, ...
... sky looked blue, like a great body of water overhead. Their conclusion was that the Sun god, Ra, sailed from east to west each day in a boat of fire. He then disappeared into the underworld until the next morning. It is likely that even the earliest nomadic people used the patterns of the Sun, Moon, ...
PDF only - at www.arxiv.org.
... and a secondary disk seen in scattered light (5,9). The CO J=3-‐2 emission totals 7.6±0.8x10-‐20 W/m2. Assuming a range of possible excitation temperatures from 20K (measured from UV absorption ...
... and a secondary disk seen in scattered light (5,9). The CO J=3-‐2 emission totals 7.6±0.8x10-‐20 W/m2. Assuming a range of possible excitation temperatures from 20K (measured from UV absorption ...
Molecules in Space
... been observed, usually for several different transitions, in a number of molecules including water, OH, SiO, methanol, and ammonia.(33,34) Maser transitions can arise because collisions, typically with dominant species H2 , preferentially populate certain excited states resulting in population inver ...
... been observed, usually for several different transitions, in a number of molecules including water, OH, SiO, methanol, and ammonia.(33,34) Maser transitions can arise because collisions, typically with dominant species H2 , preferentially populate certain excited states resulting in population inver ...
Astronomy, Astrophysics, and Cosmology
... Stellar structure on main sequence + described by spherically symmetric system in hydrostatic equilibrium ...
... Stellar structure on main sequence + described by spherically symmetric system in hydrostatic equilibrium ...
The GalMer database: galaxy mergers in the virtual observatory*
... decades later (Dressler 1980): dense regions of the Universe, where galaxy collisions are supposed to be more frequent, contain larger fractions of early-type galaxies than sparsely populated areas. Toomre & Toomre (1972) were the first to suggest that interactions “tend to bring deep into a galaxy ...
... decades later (Dressler 1980): dense regions of the Universe, where galaxy collisions are supposed to be more frequent, contain larger fractions of early-type galaxies than sparsely populated areas. Toomre & Toomre (1972) were the first to suggest that interactions “tend to bring deep into a galaxy ...
The Hydrogen Ionization Front-Photosphere
... Temperature at which Hydrogen ionizes is somewhat independent of density for low densities. Thus, when the HIF-photosphere are engaged, temperature of stellar photosphere is somewhat independent of global stellar properties, such as period, at low densities. This can lead to changes in the periodcol ...
... Temperature at which Hydrogen ionizes is somewhat independent of density for low densities. Thus, when the HIF-photosphere are engaged, temperature of stellar photosphere is somewhat independent of global stellar properties, such as period, at low densities. This can lead to changes in the periodcol ...
Lecture Notes
... because the brightness of the supernova depends on the (unknown) mass of the progenitor. A second class of supernova arises from the entirely distinct process of accretion onto a white dwarf in a binary system. As the mass approaches the ‘Chandrasekhar limit’ of 1.4M , the increasing temperature an ...
... because the brightness of the supernova depends on the (unknown) mass of the progenitor. A second class of supernova arises from the entirely distinct process of accretion onto a white dwarf in a binary system. As the mass approaches the ‘Chandrasekhar limit’ of 1.4M , the increasing temperature an ...
pasta Jos´e A. Pons , Daniele Vigan`o and Nanda Rea
... explosion of massive stars. Up to the present time, however, despite important breakthrough discoveries [1, 2, 3] we still fall short (see e.g. [4] for a recent review). The majority of neutron stars are observed as radio-pulsars with magnetic fields in the ∼ 1011 − 1013 G range, that spin down due ...
... explosion of massive stars. Up to the present time, however, despite important breakthrough discoveries [1, 2, 3] we still fall short (see e.g. [4] for a recent review). The majority of neutron stars are observed as radio-pulsars with magnetic fields in the ∼ 1011 − 1013 G range, that spin down due ...
Circular Polarization in Magnetized Wind Recombination Lines
... • temperature-sensitive spectral lines ...
... • temperature-sensitive spectral lines ...
PDF only - at www.arxiv.org.
... 1972 (Hartogh et al. 2010). While the column density is (within the error bars) compatible with the 1972 observations and shows only small deviations to recent ground-based in situ measurements of Curiosity, HIFI derived deviations from the constant vertical altitude profile not predict ...
... 1972 (Hartogh et al. 2010). While the column density is (within the error bars) compatible with the 1972 observations and shows only small deviations to recent ground-based in situ measurements of Curiosity, HIFI derived deviations from the constant vertical altitude profile not predict ...
Final Exam
... d. (2 points) What is the effect of ionization on the adiabatic temperature gradient? 4. (10 points) Convection a. (3 points) Why is there a convection region near the surface of the sun? b. (2 points) Under what conditions is a convection region nearly isentropic? c. (2 points) Describe physically ...
... d. (2 points) What is the effect of ionization on the adiabatic temperature gradient? 4. (10 points) Convection a. (3 points) Why is there a convection region near the surface of the sun? b. (2 points) Under what conditions is a convection region nearly isentropic? c. (2 points) Describe physically ...
Main-Sequence Stars and the Sun
... to 2nd transition in hydrogen will be relevant. The variation of the prominent absorption lines in the visible part of the spectrum with spectral class, and their relation to the surface temperature of the star is as follows. Hydrogen Balmer lines. Absorption lines caused by hydrogen atoms that are ...
... to 2nd transition in hydrogen will be relevant. The variation of the prominent absorption lines in the visible part of the spectrum with spectral class, and their relation to the surface temperature of the star is as follows. Hydrogen Balmer lines. Absorption lines caused by hydrogen atoms that are ...
laboratory analysis of presolar silicate stardust from a
... presolar silicate grain found in the fine-grained fraction of the Antarctic CR2 chondrite Graves Nunataks 95229. The grain is characterized by an extremely high 17 O/16 O ratio (6.3 ± 0.2 × 10−3 ) relative to solar values, whereas its 18 O/16 O ratio is solar within measurement uncertainty. It also ...
... presolar silicate grain found in the fine-grained fraction of the Antarctic CR2 chondrite Graves Nunataks 95229. The grain is characterized by an extremely high 17 O/16 O ratio (6.3 ± 0.2 × 10−3 ) relative to solar values, whereas its 18 O/16 O ratio is solar within measurement uncertainty. It also ...
White Dwarf Stars
... an object support itself against its own gravity? What processes could make such a star? Today we can answer these questions. During a star’s lifetime there are two forces fighting for control. The first is the inward force of gravity, trying to compress the star to as small a point as possible. Opp ...
... an object support itself against its own gravity? What processes could make such a star? Today we can answer these questions. During a star’s lifetime there are two forces fighting for control. The first is the inward force of gravity, trying to compress the star to as small a point as possible. Opp ...
Planets and Moons - Fraser Heights Chess Club
... • A galaxy is an enormous collection of gas, dust and billions of stars held together by gravity. One galaxy can have hundreds of billions of stars and be as large as 200,000 light years across. • Galaxy is derived from the Greek galaxias meaning "milky", a reference to the Milky Way. • Many galaxie ...
... • A galaxy is an enormous collection of gas, dust and billions of stars held together by gravity. One galaxy can have hundreds of billions of stars and be as large as 200,000 light years across. • Galaxy is derived from the Greek galaxias meaning "milky", a reference to the Milky Way. • Many galaxie ...
Lecture 2: ppt, 5 MB
... Chandra Factoids Chandra flies 200 times higher than Hubble - more than 1/3 of the way to the moon! Chandra can observe X-rays from clouds of gas so vast that it takes light five million years to go from one side to the other! During maneuvers from one target to the next, Chandra slews more s ...
... Chandra Factoids Chandra flies 200 times higher than Hubble - more than 1/3 of the way to the moon! Chandra can observe X-rays from clouds of gas so vast that it takes light five million years to go from one side to the other! During maneuvers from one target to the next, Chandra slews more s ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.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.