What To See Telescope(Jul-Sept) v1 - One
... telescope. If your telescope has a larger aperture than 4 inches, then you will see more detail in most objects. Sights that benefit from larger-aperture telescopes, and descriptions of what you will see with a 6-inch or 8-inch telescope are included where appropriate. The guide also assumes you are ...
... telescope. If your telescope has a larger aperture than 4 inches, then you will see more detail in most objects. Sights that benefit from larger-aperture telescopes, and descriptions of what you will see with a 6-inch or 8-inch telescope are included where appropriate. The guide also assumes you are ...
Program and Abstract Book - European Southern Observatory
... Mike Dunham (SUNY Fredonia, NY, USA) Stars form from the gravitational collapse of dense molecular cloud cores. In the protostellar phase, mass both accretes from the core onto a protostar, likely through an accretion disk, and is ejected in the form of jets and outflows. It is during this protostel ...
... Mike Dunham (SUNY Fredonia, NY, USA) Stars form from the gravitational collapse of dense molecular cloud cores. In the protostellar phase, mass both accretes from the core onto a protostar, likely through an accretion disk, and is ejected in the form of jets and outflows. It is during this protostel ...
The Evolution of Molecular Clouds
... first possibility, i.e. the building of large clouds from smaller ones by random collisions and coalescence, predicts formation times of at least 100 Myr for giant molecular clouds, and therefore probably cannot be the primary formation mechanism because this is longer than the cloud formation times ...
... first possibility, i.e. the building of large clouds from smaller ones by random collisions and coalescence, predicts formation times of at least 100 Myr for giant molecular clouds, and therefore probably cannot be the primary formation mechanism because this is longer than the cloud formation times ...
The old globular cluster system of the dIrr galaxy NGC 1427A in the
... (2000) and Harris (2003). In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxie ...
... (2000) and Harris (2003). In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxie ...
The Clouds
... young stars. The bright stars light up the cloud material nearby producing the magnificent Orion Nebula which we see in reflected light. In addition, molecular gas is photo-dissociated by the far-ultraviolet radiation from the OB stars, producing very strong infrared emission in the fine-structure l ...
... young stars. The bright stars light up the cloud material nearby producing the magnificent Orion Nebula which we see in reflected light. In addition, molecular gas is photo-dissociated by the far-ultraviolet radiation from the OB stars, producing very strong infrared emission in the fine-structure l ...
Astronomy Astrophysics Detailed abundances of a large sample of giant stars in... and in the Sagittarius nucleus
... polluters, are those of the metal-rich component. These observations can be understood if the burst of star formation giving birth to the metal-rich component was delayed by as much as 10−30 Myr with respect to the metal-poor one. The evolution of these massive GCs can be easily reconciled in the ge ...
... polluters, are those of the metal-rich component. These observations can be understood if the burst of star formation giving birth to the metal-rich component was delayed by as much as 10−30 Myr with respect to the metal-poor one. The evolution of these massive GCs can be easily reconciled in the ge ...
The Norma cluster (ACO3627) – II. The near-infrared Ks
... other cosmetic defects resulting from the cleaning process. In a few cases, bright stars covering galaxies are not removed by KILLALL. These are dealt with individually. The galaxy is modelled using the ELLIPSE and BMODEL tasks within the ISOPHOTE package. Sigma clipping is applied to mask out the s ...
... other cosmetic defects resulting from the cleaning process. In a few cases, bright stars covering galaxies are not removed by KILLALL. These are dealt with individually. The galaxy is modelled using the ELLIPSE and BMODEL tasks within the ISOPHOTE package. Sigma clipping is applied to mask out the s ...
Mergers of massive main sequence binaries
... AS systems), the secondary remains in thermal equilibrium and expands as it accretes mass from the primary (point B in Fig. 4(b)). Then the secondary overtakes the primary (point C in Fig. 4(b)) and eventually a contact binary is formed. From this it is clear that in case AR systems, mass transfer c ...
... AS systems), the secondary remains in thermal equilibrium and expands as it accretes mass from the primary (point B in Fig. 4(b)). Then the secondary overtakes the primary (point C in Fig. 4(b)) and eventually a contact binary is formed. From this it is clear that in case AR systems, mass transfer c ...
19_Testbank - Lick Observatory
... would be? Explain. Answer: A star made of only helium and hydrogen would have to be among the first generation of stars ever born, arising out of the primordial mix of elements that came from the Big Bang. The oldest stars we know about are over 12-15 billion years old—a star made of only helium and ...
... would be? Explain. Answer: A star made of only helium and hydrogen would have to be among the first generation of stars ever born, arising out of the primordial mix of elements that came from the Big Bang. The oldest stars we know about are over 12-15 billion years old—a star made of only helium and ...
Spectral classification of O–M stars on the basis of UBV photometry
... In the process of spectral classification, about 60% of analyzed stars have been assigned to a single or two rather close estimates of spectra. In the last case an average value was adopted. Another 40% of stars have obtained two substantially different estimates of spectra. Double results of the cl ...
... In the process of spectral classification, about 60% of analyzed stars have been assigned to a single or two rather close estimates of spectra. In the last case an average value was adopted. Another 40% of stars have obtained two substantially different estimates of spectra. Double results of the cl ...
Early-type stars in the core of the young open cluster Westerlund 2
... cluster displays significant photometric variability above 1% at the 1-σ level. The twelve brightest O-type stars are found to have spectral types between O3 and O6.5, significantly earlier than previously thought. Conclusions. The distance of the early-type stars in Westerlund 2 is established to b ...
... cluster displays significant photometric variability above 1% at the 1-σ level. The twelve brightest O-type stars are found to have spectral types between O3 and O6.5, significantly earlier than previously thought. Conclusions. The distance of the early-type stars in Westerlund 2 is established to b ...
The Life of a Star
... @r 4r. If the shell is supposed to be at rest (hydrostatic equilibrium), the sum is 0 and we obtain: ...
... @r 4r. If the shell is supposed to be at rest (hydrostatic equilibrium), the sum is 0 and we obtain: ...
2 Galaxy morphology and classification
... The spheroid is the smooth elliptical distribution of stars found in elliptical galaxies. It is composed primarily of an old, metal-poor, population of stars typically having ages „ 12 Gyr or more. The spheroid is thought to be among the first stellar components to form. The stellar halo is a di↵use ...
... The spheroid is the smooth elliptical distribution of stars found in elliptical galaxies. It is composed primarily of an old, metal-poor, population of stars typically having ages „ 12 Gyr or more. The spheroid is thought to be among the first stellar components to form. The stellar halo is a di↵use ...
The role of black holes in galaxy formation and evolution
... Galaxies come in two basic types: ‗football-shaped‘ ellipticals and ‗disk-shaped‘ spirals (Fig. 1). Spirals contain plenty of cold gas, which forms stars, whereas the gas in ellipticals is too hot to form stars. Thus, ellipticals lack the young blue stars that are usually seen in spirals, and are g ...
... Galaxies come in two basic types: ‗football-shaped‘ ellipticals and ‗disk-shaped‘ spirals (Fig. 1). Spirals contain plenty of cold gas, which forms stars, whereas the gas in ellipticals is too hot to form stars. Thus, ellipticals lack the young blue stars that are usually seen in spirals, and are g ...
3D Tour of the Universe Template
... regions, resulting in the formation of new young stars. As is common in these kinds of encounters, spiral structure was induced in the more massive galaxy. M51 is an easily found astronomical showpiece if the sky is dark, where suggestions of its spiral arms may be visible. As is also common with th ...
... regions, resulting in the formation of new young stars. As is common in these kinds of encounters, spiral structure was induced in the more massive galaxy. M51 is an easily found astronomical showpiece if the sky is dark, where suggestions of its spiral arms may be visible. As is also common with th ...
Physics of Star Formation: Milky Way and Beyond
... AU separations), such that the wide binaries show a preferred alignment with the semi-major axis of their parent core, whereas the tight binaries show no preferred orientations. We conduct several simple evolutionary models to explain the observed populations of binaries and individual stars, findi ...
... AU separations), such that the wide binaries show a preferred alignment with the semi-major axis of their parent core, whereas the tight binaries show no preferred orientations. We conduct several simple evolutionary models to explain the observed populations of binaries and individual stars, findi ...
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 ...
A Comet-Hunter`s Legacy -
... more on the visible light of stars, and the dust obscuring that light, than on the infrared radiation of the heated gases sweeping away from the galaxy. Numerous globular clusters are revealed, which have a surprising property. Usually, globular clusters, such as those in our own galaxy, are ten to ...
... more on the visible light of stars, and the dust obscuring that light, than on the infrared radiation of the heated gases sweeping away from the galaxy. Numerous globular clusters are revealed, which have a surprising property. Usually, globular clusters, such as those in our own galaxy, are ten to ...
Chapter 1: Introduction to Galaxies File - QMplus
... bulge, and the quantity of interstellar gas. [Created with blue-band data from the SuperCOSMOS Sky Survey.] Some classification schemes include more extreme subtypes Sd and Sm. Subtypes of barred spirals are denoted SBa, SBab, SBb, SBbc, SBc, ... Because the spiral arms mark regions of recent star f ...
... bulge, and the quantity of interstellar gas. [Created with blue-band data from the SuperCOSMOS Sky Survey.] Some classification schemes include more extreme subtypes Sd and Sm. Subtypes of barred spirals are denoted SBa, SBab, SBb, SBbc, SBc, ... Because the spiral arms mark regions of recent star f ...
My Constellation
... glitters with an unusual metallic red while the entire region is bathed in a pale red nebula, lit from the same star. This red supergiant has a visual binary that just might be visible, depending on local conditions and the size of one's scope (see below). The star is estimated to be between 285 sun ...
... glitters with an unusual metallic red while the entire region is bathed in a pale red nebula, lit from the same star. This red supergiant has a visual binary that just might be visible, depending on local conditions and the size of one's scope (see below). The star is estimated to be between 285 sun ...
The Milky Way Galaxy
... A Hubble search for red dwarfs turned up too few to account for dark matter If enough existed, they should have been detected ...
... A Hubble search for red dwarfs turned up too few to account for dark matter If enough existed, they should have been detected ...
Abstract - UChicago High Energy Physics
... important role in the nucleosynthesis that takes place in and around disks [6–9]. For example, the wind outflows [10, 11] above disks can be home to nucleosynthesis, including perhaps the r-process, depending on neutrino flavor composition [2, 9, 12–16]. The neutrino flavor composition above the neu ...
... important role in the nucleosynthesis that takes place in and around disks [6–9]. For example, the wind outflows [10, 11] above disks can be home to nucleosynthesis, including perhaps the r-process, depending on neutrino flavor composition [2, 9, 12–16]. The neutrino flavor composition above the neu ...
Extragalactic Distances from Planetary Nebulae
... To produce 600 L of [O III] emission, a central star must have a luminosity of L > 6,000 L. A central star with L > 6,000 L must be more massive than M > 0.6 M. Such stars come from M > 2 M progenitors. ...
... To produce 600 L of [O III] emission, a central star must have a luminosity of L > 6,000 L. A central star with L > 6,000 L must be more massive than M > 0.6 M. Such stars come from M > 2 M progenitors. ...
the Local Group - Simon P Driver
... classifying the Local Group • the Local Group has only about 10 significant galaxies (L > 108 Lsolar), so does not qualify as a cluster – NB, dwarf spheroidals etc. are not detectable at large distances, so don’t make up part of the total galaxy count for the Local Group • about half of known gal ...
... classifying the Local Group • the Local Group has only about 10 significant galaxies (L > 108 Lsolar), so does not qualify as a cluster – NB, dwarf spheroidals etc. are not detectable at large distances, so don’t make up part of the total galaxy count for the Local Group • about half of known gal ...
Weakened magnetic braking as the origin of anomalously
... rotators; and the sharp transition from slow to rapid rotation that occurs in hot stars (of greater than 6,250 K) because of their thinning convective envelopes14. Under traditional prescriptions, stars undergo braking throughout their main-sequence lifetimes, regardless of rotation rate. Observatio ...
... rotators; and the sharp transition from slow to rapid rotation that occurs in hot stars (of greater than 6,250 K) because of their thinning convective envelopes14. Under traditional prescriptions, stars undergo braking throughout their main-sequence lifetimes, regardless of rotation rate. Observatio ...
Open cluster
An open cluster, also known as galactic cluster, is a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way Galaxy, and many more are thought to exist. They are loosely bound by mutual gravitational attraction and become disrupted by close encounters with other clusters and clouds of gas as they orbit the galactic center, resulting in a migration to the main body of the galaxy as well as a loss of cluster members through internal close encounters. Open clusters generally survive for a few hundred million years, with the most massive ones surviving for a few billion years. In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for longer. Open clusters have been found only in spiral and irregular galaxies, in which active star formation is occurring.Young open clusters may still be contained within the molecular cloud from which they formed, illuminating it to create an H II region. Over time, radiation pressure from the cluster will disperse the molecular cloud. Typically, about 10% of the mass of a gas cloud will coalesce into stars before radiation pressure drives the rest of the gas away.Open clusters are key objects in the study of stellar evolution. Because the cluster members are of similar age and chemical composition, their properties (such as distance, age, metallicity and extinction) are more easily determined than they are for isolated stars. A number of open clusters, such as the Pleiades, Hyades or the Alpha Persei Cluster are visible with the naked eye. Some others, such as the Double Cluster, are barely perceptible without instruments, while many more can be seen using binoculars or telescopes. The Wild Duck Cluster, M11, is an example.