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... assignment. They will be submitting three items for this portion of the activity. Explain that they will be completing the following three activities: They must plot a point for each star in the proper location of the H-R Diagram. They must properly answer the 5 guiding questions (see section be ...
... assignment. They will be submitting three items for this portion of the activity. Explain that they will be completing the following three activities: They must plot a point for each star in the proper location of the H-R Diagram. They must properly answer the 5 guiding questions (see section be ...
DUSTY CIRCUMSTELLAR DISKS B. Zuckerman
... The most dramatic of these IR-bright, low-luminosity, stars are found in the TWA, specifically HD 98800 (K5), Hen3-600 (M2), and TW Hydrae itself (K7). At each star the dust optical depth, tau, is approximately 0.1 (Zuckerman & Becklin 1993a, Zuckerman et al. 1995a), an order of magnitude larger tha ...
... The most dramatic of these IR-bright, low-luminosity, stars are found in the TWA, specifically HD 98800 (K5), Hen3-600 (M2), and TW Hydrae itself (K7). At each star the dust optical depth, tau, is approximately 0.1 (Zuckerman & Becklin 1993a, Zuckerman et al. 1995a), an order of magnitude larger tha ...
Program and Abstract Book - European Southern Observatory
... condense into higher density clumps to form individual stars or stellar clusters. The study of the kinematics of the filaments through single-dish observations suggests the presence of gas flows along the filaments, oscillatory motions due to gravity infall, and the existence of substructure inside ...
... condense into higher density clumps to form individual stars or stellar clusters. The study of the kinematics of the filaments through single-dish observations suggests the presence of gas flows along the filaments, oscillatory motions due to gravity infall, and the existence of substructure inside ...
Excitation of Solar-like Oscillations: From PMS to MS Stellar Models
... oscillation life-times for α Cen A. Those data enable us to constrain P for that star. The approach adopted in the case of the sun has thus been extended to the case of α Cen A and large discrepancies have been found for this star between predicted P and “observed” P (see Samadi et al. 2004). For ot ...
... oscillation life-times for α Cen A. Those data enable us to constrain P for that star. The approach adopted in the case of the sun has thus been extended to the case of α Cen A and large discrepancies have been found for this star between predicted P and “observed” P (see Samadi et al. 2004). For ot ...
ASTRONOMIA SPAIN inglés.qxd
... International Year of Astronomy. In order to celebrate that event, the Spanish Astronomical Society (Sociedad Española de Astronomía, SEA) had the idea of publishing a book summarising the history of modern Spanish Astronomy through the personal views of the researches themselves through their disco ...
... International Year of Astronomy. In order to celebrate that event, the Spanish Astronomical Society (Sociedad Española de Astronomía, SEA) had the idea of publishing a book summarising the history of modern Spanish Astronomy through the personal views of the researches themselves through their disco ...
Chemo-spectrophotometric evolution of spiral galaxies ± II. Main
... Evolution of spiral galaxies ± II the simple scaling relations for galactic discs (established in the framework of SAMs; see Section 2.2) in order to derive initial gaseous profiles. They subsequently calculate the full chemical and spectrophotometric evolution of such discs for the case of low sur ...
... Evolution of spiral galaxies ± II the simple scaling relations for galactic discs (established in the framework of SAMs; see Section 2.2) in order to derive initial gaseous profiles. They subsequently calculate the full chemical and spectrophotometric evolution of such discs for the case of low sur ...
molecular cloud evolution. ii. from cloud formation to the
... et al. 2005, 2006; Paper I) suggest that the clumpiness is generated by the shock compression, which nonlinearly triggers the thermal instability, induces supersonic turbulence, and causes the formation of dense clumps in the compressed layers. It is thus essential to model the evolution of the clou ...
... et al. 2005, 2006; Paper I) suggest that the clumpiness is generated by the shock compression, which nonlinearly triggers the thermal instability, induces supersonic turbulence, and causes the formation of dense clumps in the compressed layers. It is thus essential to model the evolution of the clou ...
THE PERIOD OF ROTATION OF THE SUN
... the gas physics to create the models; we assumed the gas was thin enough that once an Xray photon is emitted by an atom, it escapes the gas (the gas is what astronomers call “optically thin”). In reality, the gas is probably dense enough in some regions to reabsorb the X-rays, and this changes the r ...
... the gas physics to create the models; we assumed the gas was thin enough that once an Xray photon is emitted by an atom, it escapes the gas (the gas is what astronomers call “optically thin”). In reality, the gas is probably dense enough in some regions to reabsorb the X-rays, and this changes the r ...
book_text4
... times larger. As well as being able to take sharper wide-field images, the other huge advantage Hubble has over ground-based telescopes is its ability to observe the near-infrared and ultraviolet light that is otherwise filtered away or masked by the atmosphere before it can reach the ground. In man ...
... times larger. As well as being able to take sharper wide-field images, the other huge advantage Hubble has over ground-based telescopes is its ability to observe the near-infrared and ultraviolet light that is otherwise filtered away or masked by the atmosphere before it can reach the ground. In man ...
1. INTRODUCTION - Institut für Theoretische Astrophysik
... emission in these lines and the observed basal Ñux emission, which had been suspected to be due to nonmagnetic (i.e., acoustic) heating operating in all late-type stars. The height dependence of the acoustic energy Ñux can be explained by the limiting strength property of the acoustic shocks and is ...
... emission in these lines and the observed basal Ñux emission, which had been suspected to be due to nonmagnetic (i.e., acoustic) heating operating in all late-type stars. The height dependence of the acoustic energy Ñux can be explained by the limiting strength property of the acoustic shocks and is ...
Chapter 24
... Like our own Galaxy, they are simply rich enough in interstellar gas to provide for continued stellar birth. Most spirals are not seen face-on, as they are shown in Figure 24.2. Many are tilted with respect to our line of sight, making their spiral structure hard to discern. However, we do not need ...
... Like our own Galaxy, they are simply rich enough in interstellar gas to provide for continued stellar birth. Most spirals are not seen face-on, as they are shown in Figure 24.2. Many are tilted with respect to our line of sight, making their spiral structure hard to discern. However, we do not need ...
Chapter 16--Properties of Stars
... Figure 16.3 Parallax makes the apparent position of a nearby star shift back and forth with respect to distant stars over the course of each year. If we measure the parallax angle p in arcseconds, the distance d to the star in parsecs is 1p. The angle in this figure is greatly exaggerated: All sta ...
... Figure 16.3 Parallax makes the apparent position of a nearby star shift back and forth with respect to distant stars over the course of each year. If we measure the parallax angle p in arcseconds, the distance d to the star in parsecs is 1p. The angle in this figure is greatly exaggerated: All sta ...
The Chemical Composition of Carbon-Rich, Very Metal
... put forward to account for the moderately metal-poor classical CH stars ([Fe/H]∼ −1.5). These are usually explained by a model involving mass transfer from a carbon-enhanced asymptotic giant branch (AGB) star (one that has since evolved to the white dwarf stage and cannot now be seen) to its lower-m ...
... put forward to account for the moderately metal-poor classical CH stars ([Fe/H]∼ −1.5). These are usually explained by a model involving mass transfer from a carbon-enhanced asymptotic giant branch (AGB) star (one that has since evolved to the white dwarf stage and cannot now be seen) to its lower-m ...
Effects of interaction on the properties of spiral galaxies. II. Isolated
... the decentering degree as the displacement of the center of the most external, recorded isophote with respect to the luminosity center, normalized to the last measured radius. The values we measured are always smaller than 5%, except for NGC 6155, for which we found 10%. The average decentering amou ...
... the decentering degree as the displacement of the center of the most external, recorded isophote with respect to the luminosity center, normalized to the last measured radius. The values we measured are always smaller than 5%, except for NGC 6155, for which we found 10%. The average decentering amou ...
A Very Dense Low-Mass Molecular Condensation in Taurus
... H 1 3 CO + J — 4-3 emission toward any starless condensations. The intensity of these H 1 3 CO + lines appears to be a good indicator of the molecular density, since the line is excited only at a density of > 10 5 - 6 c m - 3 . The intensity of the H 1 3 CO + J = 3-2 line is in fact found to be well ...
... H 1 3 CO + J — 4-3 emission toward any starless condensations. The intensity of these H 1 3 CO + lines appears to be a good indicator of the molecular density, since the line is excited only at a density of > 10 5 - 6 c m - 3 . The intensity of the H 1 3 CO + J = 3-2 line is in fact found to be well ...
here - Ira-Inaf
... identifying the region of the Galaxy deemed suitable for the formation of intelligent life. Stars between spiral arms within a narrow (0.5 kpc) annulus that is centered at the Galaxy’s corotation radius [taken to be 10.1 kpc by Balázs (1986) with the Sun assumed to be 10 kpc from the Galactic ...
... identifying the region of the Galaxy deemed suitable for the formation of intelligent life. Stars between spiral arms within a narrow (0.5 kpc) annulus that is centered at the Galaxy’s corotation radius [taken to be 10.1 kpc by Balázs (1986) with the Sun assumed to be 10 kpc from the Galactic ...
distance
... It took until the early 20th century just to realize that the fuzzy blobs (called “spiral nebulae” at the time) seen from Earth are other galaxies. ...
... It took until the early 20th century just to realize that the fuzzy blobs (called “spiral nebulae” at the time) seen from Earth are other galaxies. ...
Lives of Stars - Astronomy Outreach
... MINERVA: Yep, I remember feeling like I was gonna hurl that whole time. PAGE: The helium core consumed helium rapidly, because of the high temperature. Plus, you didn’t start off with a lot of helium. SOL: Only about 24% of my initial mass before this stage was helium. As a red giant, most of it was ...
... MINERVA: Yep, I remember feeling like I was gonna hurl that whole time. PAGE: The helium core consumed helium rapidly, because of the high temperature. Plus, you didn’t start off with a lot of helium. SOL: Only about 24% of my initial mass before this stage was helium. As a red giant, most of it was ...
Hot Horizontal Branch Stars in the Galactic Bulge. I
... D’Cruz et al. 1996). It may also be accomplished with deep mixing, and thus accompanied by light-element enhancements (Sweigart 1997; Kraft et al. 1998). However, binary mass transfer may play a dominant role at the hot end of the BHB, since a large fraction of field sdB/O stars are found to be bina ...
... D’Cruz et al. 1996). It may also be accomplished with deep mixing, and thus accompanied by light-element enhancements (Sweigart 1997; Kraft et al. 1998). However, binary mass transfer may play a dominant role at the hot end of the BHB, since a large fraction of field sdB/O stars are found to be bina ...
The Norma cluster (ACO3627) – II. The near-infrared Ks
... cluster of galaxies (Kraan-Korteweg et al. 1996; Woudt 1998), with properties comparable to the Coma cluster (Mazure et al. 1998). It has remained relatively unexplored in comparison to its well-known counterpart, mainly because of its location at low Galactic latitudes in the southern zone of avoid ...
... cluster of galaxies (Kraan-Korteweg et al. 1996; Woudt 1998), with properties comparable to the Coma cluster (Mazure et al. 1998). It has remained relatively unexplored in comparison to its well-known counterpart, mainly because of its location at low Galactic latitudes in the southern zone of avoid ...
Lecture 2 Astronomical Distances
... HST sees Cepheids to D = 10-20 Mpc. H0 x D = 70 x 15 ~ 1000 km/s. not really far enough galaxy pecular velocities ~500 km/s. galaxies falling toward Virgo cluster. ...
... HST sees Cepheids to D = 10-20 Mpc. H0 x D = 70 x 15 ~ 1000 km/s. not really far enough galaxy pecular velocities ~500 km/s. galaxies falling toward Virgo cluster. ...
1 Pau Amaro Seoane - modest 15-s
... We present an expression of the external gravitational field of a general ring-like object with the axial and plane symmetries such as annular disks or oval toroids with an arbitrary density distribution. The main term is that of an infinitely thin ring (Fukushima, 2010, Celest. Mech. Dyn. Astron., ...
... We present an expression of the external gravitational field of a general ring-like object with the axial and plane symmetries such as annular disks or oval toroids with an arbitrary density distribution. The main term is that of an infinitely thin ring (Fukushima, 2010, Celest. Mech. Dyn. Astron., ...
Objective Classification of Galaxy Spectra using the Information Bottleneck Method
... In one example, typical of such an approach (Ronen, Aragaon-Salamance & Lahav 1999), the star formation history was parameterized as a simple single burst or an exponentially decreasing star formation rate. However, the construction of the ensemble of galaxy spectra was done in an ad-hoc manner. Her ...
... In one example, typical of such an approach (Ronen, Aragaon-Salamance & Lahav 1999), the star formation history was parameterized as a simple single burst or an exponentially decreasing star formation rate. However, the construction of the ensemble of galaxy spectra was done in an ad-hoc manner. Her ...
View/Open - University of Hertfordshire
... The measurement of radial velocity has played a pivotal role in the analysis and understanding of the cosmos. It provides a signature of the motion of objects tracing the distribution of matter and gravitational potential. The discovery of an expanding universe by Hubble [1925] was made from radial ...
... The measurement of radial velocity has played a pivotal role in the analysis and understanding of the cosmos. It provides a signature of the motion of objects tracing the distribution of matter and gravitational potential. The discovery of an expanding universe by Hubble [1925] was made from radial ...
Abstract book
... Abstract. Most stars form in clusters, but the percentage of stars born in dense stellar systems is currently matter of controversy and depends very much on the own definition of cluster. The cluster definition and hence the morphologies of individual clusters appear to vary significantly from region ...
... Abstract. Most stars form in clusters, but the percentage of stars born in dense stellar systems is currently matter of controversy and depends very much on the own definition of cluster. The cluster definition and hence the morphologies of individual clusters appear to vary significantly from region ...
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.