the UKIRT Fundamental and Extended lists
... from Landolt’s (1983) equatorial UBVRI standards and the compilation of potential Hubble Space Telescope (HST ) reference sources by Turnshek et al. (1990), supplemented by additional main-sequence objects with solar-like colours from the old open cluster M67 (Eggen & Sandage 1964) and subgiants fro ...
... from Landolt’s (1983) equatorial UBVRI standards and the compilation of potential Hubble Space Telescope (HST ) reference sources by Turnshek et al. (1990), supplemented by additional main-sequence objects with solar-like colours from the old open cluster M67 (Eggen & Sandage 1964) and subgiants fro ...
WORD - Astrophysics
... essential questions remain for which the collecting area and angular resolution of an extremely large optical/infrared telescope will prove decisive. Many of these questions deal with the earliest and the latest stages of stellar evolution, plagued by significant unknowns. Determining the entire ste ...
... essential questions remain for which the collecting area and angular resolution of an extremely large optical/infrared telescope will prove decisive. Many of these questions deal with the earliest and the latest stages of stellar evolution, plagued by significant unknowns. Determining the entire ste ...
Shortв•`lived radioactivity in the early solar system: The Superв•`AGB
... investigating Super-AGB production of SLR heavier than iron, such as 107Pd. ...
... investigating Super-AGB production of SLR heavier than iron, such as 107Pd. ...
Chapter 17
... begins to contract under its own gravitational force; as it collapses, the center becomes hotter and hotter until nuclear fusion begins in the core. When looking at just a few atoms, the gravitational force is nowhere near strong enough to overcome the random thermal motion. Even a massive cloud of ...
... begins to contract under its own gravitational force; as it collapses, the center becomes hotter and hotter until nuclear fusion begins in the core. When looking at just a few atoms, the gravitational force is nowhere near strong enough to overcome the random thermal motion. Even a massive cloud of ...
Unit P1 - Universal Physics 2
... The “Steady State” theory This theory states that the universe has always existed as it does now and hasn’t changed. The trouble is that the night sky would be completely lit up because of the billions of stars, but it’s not, so… The “Big Bang” theory This theory states that the universe started off ...
... The “Steady State” theory This theory states that the universe has always existed as it does now and hasn’t changed. The trouble is that the night sky would be completely lit up because of the billions of stars, but it’s not, so… The “Big Bang” theory This theory states that the universe started off ...
Direct Detection of Galactic Halo Dark Matter
... to harbor a substantial amount of unseen matter. Recent observations indirectly suggest that as much as half of this “dark matter” may be in the form of old, very cool white dwarfs, the remnants of an ancient population of stars as old as the galaxy itself. We conducted a survey to find faint, cool ...
... to harbor a substantial amount of unseen matter. Recent observations indirectly suggest that as much as half of this “dark matter” may be in the form of old, very cool white dwarfs, the remnants of an ancient population of stars as old as the galaxy itself. We conducted a survey to find faint, cool ...
Chemical evolution models for the dwarf spheroidal galaxies Leo 1
... The initial total mass is the main driver of the system in their simulation, contrary to LM03 and LM04 in which the SF and wind efficiencies play the major role. Since the final gas mass predicted in their simulations is much higher than the values inferred by observations, they claim the necessity of ...
... The initial total mass is the main driver of the system in their simulation, contrary to LM03 and LM04 in which the SF and wind efficiencies play the major role. Since the final gas mass predicted in their simulations is much higher than the values inferred by observations, they claim the necessity of ...
A search for a new class of pulsating DA white dwarf stars in the DB
... While DAs can be found at all temperatures under 170 000 K down to the low temperature limit set by the age of the Galaxy, it is a remarkable and intriguing fact that few helium atmosphere white dwarfs occur in the effective temperature range between 45 000 ≥ T eff ≥ 30, 000 K. The DOs and DBs are f ...
... While DAs can be found at all temperatures under 170 000 K down to the low temperature limit set by the age of the Galaxy, it is a remarkable and intriguing fact that few helium atmosphere white dwarfs occur in the effective temperature range between 45 000 ≥ T eff ≥ 30, 000 K. The DOs and DBs are f ...
151 - ESO
... The Andromeda galaxy holds the equivalent of some 300 billion solar masses, which makes it half as wide as the Milky Way, but twice as massive. In other ways Andromeda is very much similar to the Milky Way. The two galaxies are the dominated ones in The Local Galaxy-group. The Andromeda galaxy exist ...
... The Andromeda galaxy holds the equivalent of some 300 billion solar masses, which makes it half as wide as the Milky Way, but twice as massive. In other ways Andromeda is very much similar to the Milky Way. The two galaxies are the dominated ones in The Local Galaxy-group. The Andromeda galaxy exist ...
Planet formation Abstract Megan K Pickett and Andrew J Lim
... is from this disk that the planets somehow coalesced. Close to the forming Sun, where the temperatures were high enough to vaporize most volatiles, the terrestrial planets formed by the accumulation of silicon, iron, nickel and other refractory grains into progressively larger bodies. Far from the S ...
... is from this disk that the planets somehow coalesced. Close to the forming Sun, where the temperatures were high enough to vaporize most volatiles, the terrestrial planets formed by the accumulation of silicon, iron, nickel and other refractory grains into progressively larger bodies. Far from the S ...
Does feedback help or hinder star formation? The effect of
... Stars form in cold cradles of molecular gas that are identified in observation and simulation as the Giant Molecular Clouds (GMCs). As dense gas cores within these clouds collapse into stars, they begin to emit heat into its surrounding gaseous nursery. This energy will affect the efficiency of the ...
... Stars form in cold cradles of molecular gas that are identified in observation and simulation as the Giant Molecular Clouds (GMCs). As dense gas cores within these clouds collapse into stars, they begin to emit heat into its surrounding gaseous nursery. This energy will affect the efficiency of the ...
Kinetic equilibrium of iron in the atmospheres of cool stars
... ing mostly on surface gravity). Therefore our choice of metalpoor reference stars has led to four representatives: HD 103095 (≡ Gmb 1830) as a cool main sequence star, HD 19445 as a typical subdwarf, HD 84937 as a turnoff star and HD 140283 as a moderately cool subgiant. The last two of these referen ...
... ing mostly on surface gravity). Therefore our choice of metalpoor reference stars has led to four representatives: HD 103095 (≡ Gmb 1830) as a cool main sequence star, HD 19445 as a typical subdwarf, HD 84937 as a turnoff star and HD 140283 as a moderately cool subgiant. The last two of these referen ...
Curtis/Shapley Debate – 1920 - Tufts Institute of Cosmology
... If you have a telescope or another means of seeing fainter objects, the situation changes completely. But astronomers did not always have telescopes. Humanity didn't always know the limits of our Galaxy and the existence of other galaxies - this knowledge came only this century - what was thought p ...
... If you have a telescope or another means of seeing fainter objects, the situation changes completely. But astronomers did not always have telescopes. Humanity didn't always know the limits of our Galaxy and the existence of other galaxies - this knowledge came only this century - what was thought p ...
ASTRO-114--Lecture 37-
... So in the 1800s astronomers wanted to name stars all the way down to about 9 th magnitude. Now, that’s about 300,000 stars. That’s a lot of stars. And so you can’t really give them nice names like Rigel. You can’t use Greek letters. And even if you start using numbers, it’s just gonna be a big numbe ...
... So in the 1800s astronomers wanted to name stars all the way down to about 9 th magnitude. Now, that’s about 300,000 stars. That’s a lot of stars. And so you can’t really give them nice names like Rigel. You can’t use Greek letters. And even if you start using numbers, it’s just gonna be a big numbe ...
AUGUSTE COMTE`S BLUNDER: AN ACCOUNT OF THE FIRST
... Whereas spectral classification and radial-velocity determinations were both well established as important branches of stellar astrophysics by the turn of the century, the same cannot be said of spectral analysis. William Huggins had by 1864 shown that some of the common elements, whose spectra he o ...
... Whereas spectral classification and radial-velocity determinations were both well established as important branches of stellar astrophysics by the turn of the century, the same cannot be said of spectral analysis. William Huggins had by 1864 shown that some of the common elements, whose spectra he o ...
November - Hawaiian Astronomical Society
... calendars “Wonders of Science” for a discounted $6.50 each. Pre-paid orders will need to be completed no later than the October meeting. What’s Up With the Planetarium: Joanne Bogan took the members over to the Planetarium. Stripped bare the Planetarium was cavernous and Joanne explained the renovat ...
... calendars “Wonders of Science” for a discounted $6.50 each. Pre-paid orders will need to be completed no later than the October meeting. What’s Up With the Planetarium: Joanne Bogan took the members over to the Planetarium. Stripped bare the Planetarium was cavernous and Joanne explained the renovat ...
Protostellar/PMS Mass Infall Luminosity Problem
... mass, as in the Herschel Orion Protostar Survey (HOPS, Manoj et al. 2013; Fisher et al. 2013; Stutz et al. 2013) ...
... mass, as in the Herschel Orion Protostar Survey (HOPS, Manoj et al. 2013; Fisher et al. 2013; Stutz et al. 2013) ...
Chandra Observation of Pulsar Wind Nebula
... Materials ejected by the binary system during its evolution? The mass donor is suggested to be very similar to the Sun but a slightly evolved, it can not contribute to the cloud during its lifetime. The planetary nebula surrounding the exploded white dwarf could be a source of the cloud materia ...
... Materials ejected by the binary system during its evolution? The mass donor is suggested to be very similar to the Sun but a slightly evolved, it can not contribute to the cloud during its lifetime. The planetary nebula surrounding the exploded white dwarf could be a source of the cloud materia ...
HET603-M05A01: Colours and Spectral Types: Learning about stars
... Gas particles, when in an interstellar cloud or in the photosphere of a star, are moving at random as they emit light. The hotter the gas, the more likely it is that some fast-moving particles will emit light which reaches us blue- or red-shifted. ...
... Gas particles, when in an interstellar cloud or in the photosphere of a star, are moving at random as they emit light. The hotter the gas, the more likely it is that some fast-moving particles will emit light which reaches us blue- or red-shifted. ...
Introduction
... to relatively isolated systems. As such, the sample is ideal for disentangling the internal and environmental processes driving evolution. The combination of ultraviolet, optical, near- and far-infrared imaging, nuclear and integrated optical spectroscopy, and atomic hydrogen emission line data, tra ...
... to relatively isolated systems. As such, the sample is ideal for disentangling the internal and environmental processes driving evolution. The combination of ultraviolet, optical, near- and far-infrared imaging, nuclear and integrated optical spectroscopy, and atomic hydrogen emission line data, tra ...
On the Spiral Structure of the Milky Way Galaxy
... respect to rotation about the galactic center, known as a grand design (GD) spiral, is related to quasistationary spiral-density waves due to deviations of the galaxy’s gravitational potential axial symmetry, possibly due to the presence of a bar [1] or satellites; the best-studied examples are the ...
... respect to rotation about the galactic center, known as a grand design (GD) spiral, is related to quasistationary spiral-density waves due to deviations of the galaxy’s gravitational potential axial symmetry, possibly due to the presence of a bar [1] or satellites; the best-studied examples are the ...
- UCL Discovery
... Dwarf galaxies are a good target for numerical simulations which aim to model the interstellar medium (ISM), star formation and stellar feedback in a galaxy. As dwarf galaxies are physically small, the physical resolution is higher if the simulations use a similar number of resolution elements to si ...
... Dwarf galaxies are a good target for numerical simulations which aim to model the interstellar medium (ISM), star formation and stellar feedback in a galaxy. As dwarf galaxies are physically small, the physical resolution is higher if the simulations use a similar number of resolution elements to si ...
The distribution of the ISM in the Milky Way A three
... of sight passing both through dense environments (e.g., the Galactic center) and through areas almost free of dust and gas (e.g., the Galactic poles). The way that dust and gas (both in molecular and neutral phases) are distributed inside the Galaxy not only shapes the appearance of the Galaxy in di ...
... of sight passing both through dense environments (e.g., the Galactic center) and through areas almost free of dust and gas (e.g., the Galactic poles). The way that dust and gas (both in molecular and neutral phases) are distributed inside the Galaxy not only shapes the appearance of the Galaxy in di ...
... — planetary nebulae: general — stars: AGB and post-AGB — stars: white dwarfs 1. INTRODUCTION 2014 was an important year for the study of planetary nebulae. The first planetary nebula (PN) was discovered on 12 July, 1764 when Charles Messier stumbled across the Dumbbell Nebula, M27, making 2014 their ...
Solar-type dynamo behaviour in fully convective stars without a
... Nicholas J. Wright1 & Jeremy J. Drake2 In solar-type stars (with radiative cores and convective envelopes), the magnetic field powers star spots, flares and other solar phenomena, as well as chromospheric and coronal emission at ultraviolet to X-ray wavelengths. The dynamo responsible for generating ...
... Nicholas J. Wright1 & Jeremy J. Drake2 In solar-type stars (with radiative cores and convective envelopes), the magnetic field powers star spots, flares and other solar phenomena, as well as chromospheric and coronal emission at ultraviolet to X-ray wavelengths. The dynamo responsible for generating ...
H II region
An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.