and galaxies
... molecular states are hindered in their decay, usually by some quantum mechanical decay selection rule. This can give rise to very long lifetimes for such states. For such atomic states to exist in interstellar gas etc. the density must be very small since (as on earth) random atomic collisions would ...
... molecular states are hindered in their decay, usually by some quantum mechanical decay selection rule. This can give rise to very long lifetimes for such states. For such atomic states to exist in interstellar gas etc. the density must be very small since (as on earth) random atomic collisions would ...
Giant molecular clouds: star factories
... into the numerical simulations as kinetic and/ or thermal energy into the surrounding gas (in this particular example, energy is added as a combination of kinetic and thermal). In this calculation, the amount of energy added corresponds to one supernova for every 160 M⊙ of stars formed. Unlike many ...
... into the numerical simulations as kinetic and/ or thermal energy into the surrounding gas (in this particular example, energy is added as a combination of kinetic and thermal). In this calculation, the amount of energy added corresponds to one supernova for every 160 M⊙ of stars formed. Unlike many ...
A Question of Planets - Vanderbilt University
... that their brightness varies dramatically. More recently astronomers have been studying them because they can provide important insights into how the Sun and solar system evolved. Twenty years ago, scientists thought that T Tauri stars had extremely strong solar winds blowing outward at velocities o ...
... that their brightness varies dramatically. More recently astronomers have been studying them because they can provide important insights into how the Sun and solar system evolved. Twenty years ago, scientists thought that T Tauri stars had extremely strong solar winds blowing outward at velocities o ...
the magellanic clouds newsletter - Keele University Astrophysics
... sources lies between 13 and 14.5 K, depending on the quality of the flux density measurements, with a temperature ranging from 5.8 to 20 K after removing sources with the 1% largest temperature estimates. Using seven independent methods, reliable distance estimates have been obtained for 5574 source ...
... sources lies between 13 and 14.5 K, depending on the quality of the flux density measurements, with a temperature ranging from 5.8 to 20 K after removing sources with the 1% largest temperature estimates. Using seven independent methods, reliable distance estimates have been obtained for 5574 source ...
printer-friendly version of benchmark
... As astronomers study stars, there are a number of characteristics that can be investigated: temperature, composition, luminosity, mass, motion, and more. Some characteristics are directly observable (such as temperature and some motions), while others (such as mass) require inference from other data ...
... As astronomers study stars, there are a number of characteristics that can be investigated: temperature, composition, luminosity, mass, motion, and more. Some characteristics are directly observable (such as temperature and some motions), while others (such as mass) require inference from other data ...
The Milky Way: Cartoon
... to figure out why galaxies look the way they do. What is important? Probably not bars or spiral arm winding. Text They have a spectacular effect on what galaxies look like, but are probably transient phases in a galaxy’s life. ...
... to figure out why galaxies look the way they do. What is important? Probably not bars or spiral arm winding. Text They have a spectacular effect on what galaxies look like, but are probably transient phases in a galaxy’s life. ...
A n A n c i e n... How Astronomers Know the Vast Scale of Cosmic Time
... the school science curriculum. The study of astronomy is deeply rooted in culture and philosophy. It harnesses our curiosity, imagination, and a sense of shared exploration and discovery, and it is also an area of great interest to people of all ages—especially children. With new and better telescop ...
... the school science curriculum. The study of astronomy is deeply rooted in culture and philosophy. It harnesses our curiosity, imagination, and a sense of shared exploration and discovery, and it is also an area of great interest to people of all ages—especially children. With new and better telescop ...
Summary Of the Structure of the Milky Way
... • The Distribution of stars can reveal part of the disk-like nature of the Milky Way galaxy, but are not “deep” enough probes to fully reveal the structure of the Milky Way. • Open clusters can define the thickness of the Milky Way’s thin disk where star formation is active. • Globular clusters allo ...
... • The Distribution of stars can reveal part of the disk-like nature of the Milky Way galaxy, but are not “deep” enough probes to fully reveal the structure of the Milky Way. • Open clusters can define the thickness of the Milky Way’s thin disk where star formation is active. • Globular clusters allo ...
Field Star Distributions of the Hercules Thick Disk Cloud
... We ran GALMOD with the parameters derived by Larsen and Humphreys 2003 and created model Hess diagrams for each field, shown in Figure 4. In addition to being a good match to the data, the model allowed us to determine portions of the Hess diagram dominated by disk/ halo/thick disk stars for § 2. ...
... We ran GALMOD with the parameters derived by Larsen and Humphreys 2003 and created model Hess diagrams for each field, shown in Figure 4. In addition to being a good match to the data, the model allowed us to determine portions of the Hess diagram dominated by disk/ halo/thick disk stars for § 2. ...
Today`s Powerpoint
... Mass of end products is less than mass of 4 protons by 0.7%. Mass converted to energy. 600 millions of tons per second fused. Takes billions of years to convert p's to 4He in Sun's core. Process sets lifetime of stars. Hydrostatic Equilibrium: pressure from fusion reactions balances gravity. Sun is ...
... Mass of end products is less than mass of 4 protons by 0.7%. Mass converted to energy. 600 millions of tons per second fused. Takes billions of years to convert p's to 4He in Sun's core. Process sets lifetime of stars. Hydrostatic Equilibrium: pressure from fusion reactions balances gravity. Sun is ...
Set 2: Nature of Galaxies
... • History: as late as the early 1920’s it was not known that the “spiral nebula” were galaxies like ours • Debate between Shapley (galactic objects) and Curtis (extragalactic, or galaxies) in 1920 highlighted the difficulties distances in astrophysics difficult to measure - Shapley’s inferences base ...
... • History: as late as the early 1920’s it was not known that the “spiral nebula” were galaxies like ours • Debate between Shapley (galactic objects) and Curtis (extragalactic, or galaxies) in 1920 highlighted the difficulties distances in astrophysics difficult to measure - Shapley’s inferences base ...
ASTRO 1050 The Structure of the Milky Way Galaxy
... 3. Now, we know that we live in a Galaxy that has a disk-like shape. But, where in the disk do we live? Are we at the center, or off on one side? In the early 1920s, an American astronomer named Harlow Shapley studied this question. He found that there were clusters of billions of old stars, called ...
... 3. Now, we know that we live in a Galaxy that has a disk-like shape. But, where in the disk do we live? Are we at the center, or off on one side? In the early 1920s, an American astronomer named Harlow Shapley studied this question. He found that there were clusters of billions of old stars, called ...
Binary star formation
... binaries via capture early on when the stars still have massive disks around them: ...
... binaries via capture early on when the stars still have massive disks around them: ...
The Big Bang
... • If you leave a large “protogalaxy” alone, it will most likely turn into a spiral galaxy (by conservation of angular momentum) • Disks of galaxies are very fragile; if they get hit with anything bigger than 10% of their own mass, they are destroyed (and don’t come back) • Collisions of galaxies in ...
... • If you leave a large “protogalaxy” alone, it will most likely turn into a spiral galaxy (by conservation of angular momentum) • Disks of galaxies are very fragile; if they get hit with anything bigger than 10% of their own mass, they are destroyed (and don’t come back) • Collisions of galaxies in ...
DAVID A. RIETHMILLER - Department of Physics and Astronomy
... Ph.D. Thesis Topic – Ohio University (current): My current research explores the hydrodynamic history of elliptical galaxies, simulating various prescriptions for interstellar gas cooling and AGN energy feedback against real X-ray observations of ellipticals. The goal is to isolate those prescriptio ...
... Ph.D. Thesis Topic – Ohio University (current): My current research explores the hydrodynamic history of elliptical galaxies, simulating various prescriptions for interstellar gas cooling and AGN energy feedback against real X-ray observations of ellipticals. The goal is to isolate those prescriptio ...
The star Betelgeuse is about 500 light years away from us. If this star
... a) Procyon is moving at the same speed as Acrux b) Procyon is moving more slowly than Acrux c) Procyon and Acrux are BOTH moving away from the Sun d) both b & c e) none of the above Which of the following is NOT an implication of Hubble's law? a) the Universe is expanding b) we are at the center of ...
... a) Procyon is moving at the same speed as Acrux b) Procyon is moving more slowly than Acrux c) Procyon and Acrux are BOTH moving away from the Sun d) both b & c e) none of the above Which of the following is NOT an implication of Hubble's law? a) the Universe is expanding b) we are at the center of ...
ppt - Astronomy at Swarthmore College
... Some of the other hot stars observed with Chandra show broad, blueshifted, and asymmetric line profiles, similar to those seen in ζ Pup But…some hot stars have x-ray spectra with quite narrow lines, that are especially strong and high energy - not consistent with line-force instability wind shocks ...
... Some of the other hot stars observed with Chandra show broad, blueshifted, and asymmetric line profiles, similar to those seen in ζ Pup But…some hot stars have x-ray spectra with quite narrow lines, that are especially strong and high energy - not consistent with line-force instability wind shocks ...
Lec2015_22
... • Observational evidence to date has found little evidence for significant variations in the form of the IMF (as a function of anything!) • Population III, by definition, would have been formed from gas with essentially no heavy elements. Major change to the opacity and cooling processes operative d ...
... • Observational evidence to date has found little evidence for significant variations in the form of the IMF (as a function of anything!) • Population III, by definition, would have been formed from gas with essentially no heavy elements. Major change to the opacity and cooling processes operative d ...
Lecture7
... eventually end up as white dwarfs. However, before the degeneracy sets in finally in the core, elements heavier than C and O would be synthesized. So, their core will consist of elements heavier than C and O, e.g., Mg, Si, but not Fe. However, some calculations show that some of these stars on the h ...
... eventually end up as white dwarfs. However, before the degeneracy sets in finally in the core, elements heavier than C and O would be synthesized. So, their core will consist of elements heavier than C and O, e.g., Mg, Si, but not Fe. However, some calculations show that some of these stars on the h ...
The Ionized Nebula surrounding the Red Supergiant W26 in
... previous RSG phase (e.g., Smartt et al. 2002) and the detection of similar structures around a RSG might help resolve this. While Sher 25 does have two polar outflows, one side is notably brighter than the other, which might suggest that a second outflow exists around W26 but is not detected. Altern ...
... previous RSG phase (e.g., Smartt et al. 2002) and the detection of similar structures around a RSG might help resolve this. While Sher 25 does have two polar outflows, one side is notably brighter than the other, which might suggest that a second outflow exists around W26 but is not detected. Altern ...
Galaxies - gilbertmath.com
... _________ light years across. To put this in perspective, imagine our solar system as the size of a bean. At this scale, the Milky Way galaxy would be the size of Lake Superior. ...
... _________ light years across. To put this in perspective, imagine our solar system as the size of a bean. At this scale, the Milky Way galaxy would be the size of Lake Superior. ...
PHYS3380_110415_bw - The University of Texas at Dallas
... ･After the hydrogen is used up in the core, the helium core contracts, and heats the hydrogen rich layer just outside of the core. The hydrogen ignites in the shell around the core and the Sun moves to the right in the HR diagram. ･When the outer layers of the Sun become convective, the luminosity o ...
... ･After the hydrogen is used up in the core, the helium core contracts, and heats the hydrogen rich layer just outside of the core. The hydrogen ignites in the shell around the core and the Sun moves to the right in the HR diagram. ･When the outer layers of the Sun become convective, the luminosity o ...
ASTRONOMY 301 EXAMPLES OF TEST
... (A) are dark. (B) are hotter than the rest of the surface of the Sun and make aurorae (e. g., northern lights) on Earth when they emit energetic particles. (C) are only slightly fainter than the rest of the Sun’s surface, because they are slightly cooler than the rest of the surface. (D) vary period ...
... (A) are dark. (B) are hotter than the rest of the surface of the Sun and make aurorae (e. g., northern lights) on Earth when they emit energetic particles. (C) are only slightly fainter than the rest of the Sun’s surface, because they are slightly cooler than the rest of the surface. (D) vary period ...
Lab 6
... class of variable stars called the Cepheids. These stars vary in brightness in a cyclical pattern, and are bright enough to be seen within another galaxy. Leavitt determined that absolute magnitude (M) of a Cepheid variable was mathematically related to the period (P, measured in days) of its bright ...
... class of variable stars called the Cepheids. These stars vary in brightness in a cyclical pattern, and are bright enough to be seen within another galaxy. Leavitt determined that absolute magnitude (M) of a Cepheid variable was mathematically related to the period (P, measured in days) of its bright ...
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.