The Evolution of Isotope Ratios in the Milky Way Galaxy
... some isotopes (e.g., 15 N) are negative because they are destroyed during stellar evolution. However, in chemical evolution models, it is possible that the abundances of such elements at time t is lower than the adopted initial abundances, which causes numerical problems. This is often the case for ...
... some isotopes (e.g., 15 N) are negative because they are destroyed during stellar evolution. However, in chemical evolution models, it is possible that the abundances of such elements at time t is lower than the adopted initial abundances, which causes numerical problems. This is often the case for ...
Evolution in circumstellar envelopes of Be stars: From disks to rings?
... At the same time the Fe ii and Si ii line emission reappeared with a large width. The narrower doublepeaked emission in O i 8446 had lost a bit in width and two-thirds in peak height. But it had acquired a broad pedestal with the same total width as the other two lines. Like the Hα emission, this ox ...
... At the same time the Fe ii and Si ii line emission reappeared with a large width. The narrower doublepeaked emission in O i 8446 had lost a bit in width and two-thirds in peak height. But it had acquired a broad pedestal with the same total width as the other two lines. Like the Hα emission, this ox ...
Radio pulsars
... • Young pulsars have unpredictable changes in period glitches and period noise. • Millisecond pulsars have extremely stable periods. ...
... • Young pulsars have unpredictable changes in period glitches and period noise. • Millisecond pulsars have extremely stable periods. ...
Ages of young stars
... individual objects. A reliable age scale is established above 20 Myr from measurement of the Lithium Depletion Boundary (LDB) in young clusters, and consistency is shown between these ages and those from the upper main sequence and the main sequence turn-off – if modest core convection and rotation ...
... individual objects. A reliable age scale is established above 20 Myr from measurement of the Lithium Depletion Boundary (LDB) in young clusters, and consistency is shown between these ages and those from the upper main sequence and the main sequence turn-off – if modest core convection and rotation ...
Stars, Galaxies, and Beyond
... manageable look at astronomy and astrophysics applying to space well beyond the solar system. It is likely that humankind will not reach other stars or galaxies in the foreseeable future, but our understanding of our place in the universe is remarkably enriched by pursuing this knowledge. I thank pr ...
... manageable look at astronomy and astrophysics applying to space well beyond the solar system. It is likely that humankind will not reach other stars or galaxies in the foreseeable future, but our understanding of our place in the universe is remarkably enriched by pursuing this knowledge. I thank pr ...
Ages of Young Stars
... Lithium Depletion Boundary (LDB) in young clusters, and consistency is shown between these ages and those from the upper main sequence and the main sequence turn-off – if modest core convection and rotation is included in the models of higher-mass stars. Other available methods for age estimation in ...
... Lithium Depletion Boundary (LDB) in young clusters, and consistency is shown between these ages and those from the upper main sequence and the main sequence turn-off – if modest core convection and rotation is included in the models of higher-mass stars. Other available methods for age estimation in ...
Digital Universe Guide - American Museum of Natural History
... Activating Data Groups In order to alter the properties of a data group (brightness, color, label size), you must make the data group active. By default, the stars are the active group when the Milky Way Atlas is launched. You can verify that by inspecting the active group indicator below the Groups ...
... Activating Data Groups In order to alter the properties of a data group (brightness, color, label size), you must make the data group active. By default, the stars are the active group when the Milky Way Atlas is launched. You can verify that by inspecting the active group indicator below the Groups ...
Standardized Test Prep Chapter 30 Multiple Choice, continued
... Section 1 Characterstics of Stars Section 2 Stellar Evolution ...
... Section 1 Characterstics of Stars Section 2 Stellar Evolution ...
Unlocking the secrets of stellar haloes using combined star counts
... In recent years, most attempts to trace the surface brightness profiles of stellar haloes have been based on direct star counts, i.e. by counting the number of bright halo stars (red giant branch stars, asymptotic giant branch stars and upper main sequence stars) within a certain area. The bright st ...
... In recent years, most attempts to trace the surface brightness profiles of stellar haloes have been based on direct star counts, i.e. by counting the number of bright halo stars (red giant branch stars, asymptotic giant branch stars and upper main sequence stars) within a certain area. The bright st ...
ABSTRACT Exoplanet Habitability and an Analysis of Gliese 436 b
... reception of data during the transit. The CDC camera was set to take images every thirty seconds starting about one hour before and after the transit period. At the completion of the transit, thirty flat, dark 10, dark 30, and bias images were taken. After the observing run, master flatfield, dark, ...
... reception of data during the transit. The CDC camera was set to take images every thirty seconds starting about one hour before and after the transit period. At the completion of the transit, thirty flat, dark 10, dark 30, and bias images were taken. After the observing run, master flatfield, dark, ...
Variations in Integrated Galactic Initial Mass Functions due to
... 2006, the latter WK06 from now on) pointed out that the distribution of initial stellar masses in a galaxy may significantly deviate from the initial mass function (IMF) the stars have when they are born, if the vast majority of stars is born in clusters. These clusters follow a power-law mass funct ...
... 2006, the latter WK06 from now on) pointed out that the distribution of initial stellar masses in a galaxy may significantly deviate from the initial mass function (IMF) the stars have when they are born, if the vast majority of stars is born in clusters. These clusters follow a power-law mass funct ...
Document
... Observatory (ISO, in the mid-1990s) were very useful for this kind of work, and it is being continued with the infrared camera on the Hubble Space Telescope and, at even longer infrared wavelengths, with the Spitzer Space ...
... Observatory (ISO, in the mid-1990s) were very useful for this kind of work, and it is being continued with the infrared camera on the Hubble Space Telescope and, at even longer infrared wavelengths, with the Spitzer Space ...
X. Nuclear star clusters in low-mass early-type galaxies
... computations, the theoretical framework for the dissipational formation of NSCs provides less quantitative predictions than the inspiralling cluster scenario. There is evidence that both the in situ as well as the GC inspiralling formation happen in galaxies. Evidence for the GC inspiral scenario is ...
... computations, the theoretical framework for the dissipational formation of NSCs provides less quantitative predictions than the inspiralling cluster scenario. There is evidence that both the in situ as well as the GC inspiralling formation happen in galaxies. Evidence for the GC inspiral scenario is ...
A physical interpretation of the `red Sirius` anomaly
... that Sirius becomes significantly dimmer than the other stars before it acquires a similar degree of redness. ...
... that Sirius becomes significantly dimmer than the other stars before it acquires a similar degree of redness. ...
ESA BR-170 - ESA Science
... In 1800, the German-born British astronomer and musician, William Herschel – famous for his discovery of the planet Uranus a few years earlier – described that the differently coloured filters through which he observed the Sun allowed different levels of heat to pass. He performed a simple experimen ...
... In 1800, the German-born British astronomer and musician, William Herschel – famous for his discovery of the planet Uranus a few years earlier – described that the differently coloured filters through which he observed the Sun allowed different levels of heat to pass. He performed a simple experimen ...
Joint formation of QSOs and spheroids: QSOs as clocks of star
... suggesting that star formation begins in the hosting spheroids at a time t* and proceeds vigoursly at least until the time tQSO, when the QSO shines. Here we estimate the duration of the star formation phase and its possible dependence on the mass. The statistics on broad emission lines suggest that ...
... suggesting that star formation begins in the hosting spheroids at a time t* and proceeds vigoursly at least until the time tQSO, when the QSO shines. Here we estimate the duration of the star formation phase and its possible dependence on the mass. The statistics on broad emission lines suggest that ...
Confirmation of Hostless Type Ia Supernovae Using Hubble Space
... Supernovae of Type Ia (SNe Ia) are the thermonuclear explosions of carbon-oxygen white dwarf (CO WD) stars, commonly used as cosmological standard candles although their progenitor scenario is not yet well understood (e.g., Howell 2011). Most likely, the WD is in a binary system with either another ...
... Supernovae of Type Ia (SNe Ia) are the thermonuclear explosions of carbon-oxygen white dwarf (CO WD) stars, commonly used as cosmological standard candles although their progenitor scenario is not yet well understood (e.g., Howell 2011). Most likely, the WD is in a binary system with either another ...
here
... eastern sky prior to sunrise for northern hemisphere observers and will be more easily visible at the end of the month, when it brightens to magnitude -0.3. During May, Venus shines prominently in the dawn sky. It decreases in angular diameter from 37.8 arc minutes to 24.8 arc minutes but increases ...
... eastern sky prior to sunrise for northern hemisphere observers and will be more easily visible at the end of the month, when it brightens to magnitude -0.3. During May, Venus shines prominently in the dawn sky. It decreases in angular diameter from 37.8 arc minutes to 24.8 arc minutes but increases ...
Stars, Galaxies, Superuniverses and the Urantia Book, by Frederick
... number since our galaxy is the second largest in our local cluster of about 30 galaxies, and thus may be considered to be an exceptionally large galaxy. There are many more small galaxies of the elliptical or globular types than there are of the spiral type such as our Milky Way. The information on ...
... number since our galaxy is the second largest in our local cluster of about 30 galaxies, and thus may be considered to be an exceptionally large galaxy. There are many more small galaxies of the elliptical or globular types than there are of the spiral type such as our Milky Way. The information on ...
Cygnus (constellation)
Cygnus /ˈsɪɡnəs/ is a northern constellation lying on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan. The swan is one of the most recognizable constellations of the northern summer and autumn, it features a prominent asterism known as the Northern Cross (in contrast to the Southern Cross). Cygnus was among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.Cygnus contains Deneb, one of the brightest stars in the night sky and one corner of the Summer Triangle, as well as some notable X-ray sources and the giant stellar association of Cygnus OB2. One of the stars of this association, NML Cygni, is one of the largest stars currently known. The constellation is also home to Cygnus X-1, a distant X-ray binary containing a supergiant and unseen massive companion that was the first object widely held to be a black hole. Many star systems in Cygnus have known planets as a result of the Kepler Mission observing one patch of the sky, the patch is the area around Cygnus. In addition, most of the eastern part of Cygnus is dominated by the Hercules–Corona Borealis Great Wall, a giant galaxy filament that is the largest known structure in the observable universe; covering most of the northern sky.