The Helium Flash • When the temperature of a stellar core reaches T
... • During helium core burning, the radius of the helium core will remain approximately constant. The core will not contract until the helium fraction reaches Y < 0.1. Once it does, the star will restructure itself in a manner similar to that of the hydrogenexhaustion phase. First, the stellar core w ...
... • During helium core burning, the radius of the helium core will remain approximately constant. The core will not contract until the helium fraction reaches Y < 0.1. Once it does, the star will restructure itself in a manner similar to that of the hydrogenexhaustion phase. First, the stellar core w ...
PARALLAX – IT`S SIMPLE! Abstract
... properties (core temperature, radius, mass) are also connected to the star’s luminosity. How far can parallax measurements reach? The diameter of our Galaxy is about 30 thousands parsecs, so it is clear that the HIPPARCOS satellite was able to measure distances only in the vicinity of the Sun. The a ...
... properties (core temperature, radius, mass) are also connected to the star’s luminosity. How far can parallax measurements reach? The diameter of our Galaxy is about 30 thousands parsecs, so it is clear that the HIPPARCOS satellite was able to measure distances only in the vicinity of the Sun. The a ...
The Deaths of Very Massive Stars
... not explode or explode incompletely and make black holes, especially for helium cores from 7 to 10 M⊙ . 2) From 30 to 80 M⊙ (helium core mass 10 to 35 M⊙ ), black hole formation is quite likely. Except for their winds, stars in this mass range may be nucleosynthetically barren. Again though there wi ...
... not explode or explode incompletely and make black holes, especially for helium cores from 7 to 10 M⊙ . 2) From 30 to 80 M⊙ (helium core mass 10 to 35 M⊙ ), black hole formation is quite likely. Except for their winds, stars in this mass range may be nucleosynthetically barren. Again though there wi ...
compound sentences
... B. 1. Connor had seen many parks in his life, but he never had seen a park like this one. 2. Dad brought a pair of binoculars, and Nate used them to look for animals. 3. He saw his first live bear, and the hair stood up on his arms. 4. It was an exciting moment, but it only lasted a second. 5. The b ...
... B. 1. Connor had seen many parks in his life, but he never had seen a park like this one. 2. Dad brought a pair of binoculars, and Nate used them to look for animals. 3. He saw his first live bear, and the hair stood up on his arms. 4. It was an exciting moment, but it only lasted a second. 5. The b ...
Life Stages of High
... • A star’s mass determines its entire life story because it determines its core temperature • High-mass stars with >8MSun have short lives, eventually becoming hot enough to make iron, and end in supernova explosions • Low-mass stars with <2MSun have long lives, never become hot enough to fuse carbo ...
... • A star’s mass determines its entire life story because it determines its core temperature • High-mass stars with >8MSun have short lives, eventually becoming hot enough to make iron, and end in supernova explosions • Low-mass stars with <2MSun have long lives, never become hot enough to fuse carbo ...
Life Histories Of Some Stars
... graph? Where do newborn babies cluster? Children? Or is there no clustering at all? Describe the shape of the graph? Is it a straight line? A curve? 5. Give each group the list of stars attached and the HR diagram attached. Instead of height and weight, the information is in Luminosity (compared to ...
... graph? Where do newborn babies cluster? Children? Or is there no clustering at all? Describe the shape of the graph? Is it a straight line? A curve? 5. Give each group the list of stars attached and the HR diagram attached. Instead of height and weight, the information is in Luminosity (compared to ...
Barium and europium abundances in cool dwarf stars and
... In Paper I we showed this difference can be easily detected if it exists: for example, for the star BD 66◦ 268 with [Fe/H] = −2.2 it consists of 0.2 dex in terms of abundances. However at Ba abundances derived from the Ba ii subordinate lines we could not find a marked strengthening of the Ba ii res ...
... In Paper I we showed this difference can be easily detected if it exists: for example, for the star BD 66◦ 268 with [Fe/H] = −2.2 it consists of 0.2 dex in terms of abundances. However at Ba abundances derived from the Ba ii subordinate lines we could not find a marked strengthening of the Ba ii res ...
Star formation and internal kinematics of irregular galaxies
... single star, galaxy-wide conditions are probably irrelevant. The process of cloud collapse ...
... single star, galaxy-wide conditions are probably irrelevant. The process of cloud collapse ...
PHYS3380_111115_bw - The University of Texas at Dallas
... evolution, which had suggested that supernovae would result from red supergiants. Now believe star was chemically poor in elements heavier than He - contracted and heated up after phase as cool, red supergiant during which it lost much of its mass into space Remnant - rings caused by interaction of ...
... evolution, which had suggested that supernovae would result from red supergiants. Now believe star was chemically poor in elements heavier than He - contracted and heated up after phase as cool, red supergiant during which it lost much of its mass into space Remnant - rings caused by interaction of ...
ASTRONOMY AND ASTROPHYSICS Barium and europium
... halo stars are of the r-process origin. Much observational efforts were invested in testing this idea. For extremely metalpoor stars with metallicities [Fe/H] ≤ −2.4 McWilliam (1998) has derived an average [Eu/Ba] = 0.69, consistent with pure rprocess nucleosynthesis provided that the data of Arland ...
... halo stars are of the r-process origin. Much observational efforts were invested in testing this idea. For extremely metalpoor stars with metallicities [Fe/H] ≤ −2.4 McWilliam (1998) has derived an average [Eu/Ba] = 0.69, consistent with pure rprocess nucleosynthesis provided that the data of Arland ...
The Chemical Composition of Carbon-Rich, Very Metal
... mass transfer from a binary companion that previously evolved through the asymptotic giant branch stage. By way of contrast, the other four stars we investigate exhibit no overabundances of barium ([Ba/Fe]< 0), while three of them have mildly enhanced carbon and/or nitrogen ([C+N]∼+1). We have been ...
... mass transfer from a binary companion that previously evolved through the asymptotic giant branch stage. By way of contrast, the other four stars we investigate exhibit no overabundances of barium ([Ba/Fe]< 0), while three of them have mildly enhanced carbon and/or nitrogen ([C+N]∼+1). We have been ...
THE VELOCITY DISTRIBUTION OF THE NEAREST
... The bulk flow velocity for the cluster of interstellar cloudlets within 30 pc of the Sun is determined from optical and ultraviolet absorption line data, after omitting from the sample stars with circumstellar disks or variable emission lines and the active variable HR 1099. A total of 96 velocity c ...
... The bulk flow velocity for the cluster of interstellar cloudlets within 30 pc of the Sun is determined from optical and ultraviolet absorption line data, after omitting from the sample stars with circumstellar disks or variable emission lines and the active variable HR 1099. A total of 96 velocity c ...
ASTRONOMY 113 Laboratory Lab 5: Spectral Classification of the
... spectral classification is as basic to astronomy as the Linnean system of classifying plants and animals by genus and species is to biology. Since group members are presumed to have similar physical characteristics, we can transfer knowledge gleaned about any star in the group to all stars in the gr ...
... spectral classification is as basic to astronomy as the Linnean system of classifying plants and animals by genus and species is to biology. Since group members are presumed to have similar physical characteristics, we can transfer knowledge gleaned about any star in the group to all stars in the gr ...
Mergers of massive main sequence binaries
... with the assumption of no mass loss and homogeneous mixing during the merging process. We find that there are two types of mergers which result from different phases of mass transfer. Both of these types have relatively low hydrogen content which leads to high luminosities. We then used the data of ...
... with the assumption of no mass loss and homogeneous mixing during the merging process. We find that there are two types of mergers which result from different phases of mass transfer. Both of these types have relatively low hydrogen content which leads to high luminosities. We then used the data of ...
INTERSTELLAR MedLab
... Reflection – dust clouds that reflect (scatter) a star’s light to us Dark – high densities of dust and gas that redden or extinct the light from the stars located behind the cloud. These are also where molecules are likely to be found. During the course of this laboratory exercise, you will study th ...
... Reflection – dust clouds that reflect (scatter) a star’s light to us Dark – high densities of dust and gas that redden or extinct the light from the stars located behind the cloud. These are also where molecules are likely to be found. During the course of this laboratory exercise, you will study th ...
The Sun and Stars 4.1 Energy formation and layers of the Sun 4.2
... is easy to believe that the light from stars reaches us "instantaneously," like that of a light bulb being turned on, it is only with very distant luminescent objects that we can notice that light takes time to travel. The more distant the star, the longer it will take the light to reach Earth. For ...
... is easy to believe that the light from stars reaches us "instantaneously," like that of a light bulb being turned on, it is only with very distant luminescent objects that we can notice that light takes time to travel. The more distant the star, the longer it will take the light to reach Earth. For ...
Hipparcos distance estimates of the Ophiuchus and the Lupus cloud
... Markov Chains (MCMC; see, e.g. Tanner 1991). Figure 6 shows the likelihood as a function of the cloud distance, marginalized with respect to all other parameters. From this figure we can trivially evaluate the confidence regions for the estimated distances; in particular, we obtain dOph = (119 ± 6) ...
... Markov Chains (MCMC; see, e.g. Tanner 1991). Figure 6 shows the likelihood as a function of the cloud distance, marginalized with respect to all other parameters. From this figure we can trivially evaluate the confidence regions for the estimated distances; in particular, we obtain dOph = (119 ± 6) ...
File - the ridgeway ASTRONOMY page
... As an example, our Sun’s blackbody spectrum peaks at a wavelength of around 500 x 10 -9 m, giving an effective temperature of about 5800K. National Schools’ Observatory ...
... As an example, our Sun’s blackbody spectrum peaks at a wavelength of around 500 x 10 -9 m, giving an effective temperature of about 5800K. National Schools’ Observatory ...
Chapter 31
... • The fact that the halo and bulge are made exclusively of old stars suggests that these parts of the galaxy formed first. – The galaxy began as a spherical cloud in space with the first stars forming while this cloud was round in what is now the halo. – The nuclear bulge represents the inner portio ...
... • The fact that the halo and bulge are made exclusively of old stars suggests that these parts of the galaxy formed first. – The galaxy began as a spherical cloud in space with the first stars forming while this cloud was round in what is now the halo. – The nuclear bulge represents the inner portio ...
The University of Sydney Page
... Very low mass stars Very low mass stars (mass less than about 0.4 solar masses) are different in one important respect from heavier stars: their interiors are fully convective. The fused helium is stirred through the whole star, so it has the whole of its hydrogen mass to prolong its stay on the ma ...
... Very low mass stars Very low mass stars (mass less than about 0.4 solar masses) are different in one important respect from heavier stars: their interiors are fully convective. The fused helium is stirred through the whole star, so it has the whole of its hydrogen mass to prolong its stay on the ma ...
Stellar kinematics
Stellar kinematics is the study of the movement of stars without needing to understand how they acquired their motion. This differs from stellar dynamics, which takes into account gravitational effects. The motion of a star relative to the Sun can provide useful information about the origin and age of a star, as well as the structure and evolution of the surrounding part of the Milky Way.In astronomy, it is widely accepted that most stars are born within molecular clouds known as stellar nurseries. The stars formed within such a cloud compose open clusters containing dozens to thousands of members. These clusters dissociate over time. Stars that separate themselves from the cluster's core are designated as members of the cluster's stellar association. If the remnant later drifts through the Milky Way as a coherent assemblage, then it is termed a moving group.