proper motion
... will last only 30 million years. A star with 0.25 solar masses can last 320 billion years. ...
... will last only 30 million years. A star with 0.25 solar masses can last 320 billion years. ...
Evolution of our Sun
... About how long does our star live as a main sequence star? Explain why a massive star only lives a short time? What elements are created in a sun-like star? What elements are created in a massive star? Evolution of the Sun – Part 2 Name and briefly describe the stages that our sun will go through as ...
... About how long does our star live as a main sequence star? Explain why a massive star only lives a short time? What elements are created in a sun-like star? What elements are created in a massive star? Evolution of the Sun – Part 2 Name and briefly describe the stages that our sun will go through as ...
Slide 1
... appears when viewed from Earth; it depends on the absolute brightness but also on the distance of the star: ...
... appears when viewed from Earth; it depends on the absolute brightness but also on the distance of the star: ...
Shining Light on the Stars: The Hertzsprung-Russell
... distance of just over 4.2 light years, or 24 trillion miles, this star is our closest stellar neighbor. The surface of Proxima Centauri appears more mottled than our Sun because red dwarf stars have larger and more star spots. If you look off to the right you can see two other stars nearby. Proxima ...
... distance of just over 4.2 light years, or 24 trillion miles, this star is our closest stellar neighbor. The surface of Proxima Centauri appears more mottled than our Sun because red dwarf stars have larger and more star spots. If you look off to the right you can see two other stars nearby. Proxima ...
ASTR-1020: Astronomy II Course Lecture Notes Section III
... 1. Three properties of stars are responsible for the appearance of a stellar spectrum: a) Temperature: Shifts λmax =⇒ hot stars are bluish, cool stars are reddish. Affects the ionization and excitation of atoms in the stellar atmosphere =⇒ hot stars have high-ionization lines, cool stars have neutra ...
... 1. Three properties of stars are responsible for the appearance of a stellar spectrum: a) Temperature: Shifts λmax =⇒ hot stars are bluish, cool stars are reddish. Affects the ionization and excitation of atoms in the stellar atmosphere =⇒ hot stars have high-ionization lines, cool stars have neutra ...
astro-ph/9505110 PDF
... solar in H II region. However, Pettini & Lipman (1995) have criticized that analysis: they argue that the O I line is highly saturated, and that the b-value derived from H I 21cm emission is not likely to be appropriate for the absorption line of sight. They modeled the Kunth et al. O I line for var ...
... solar in H II region. However, Pettini & Lipman (1995) have criticized that analysis: they argue that the O I line is highly saturated, and that the b-value derived from H I 21cm emission is not likely to be appropriate for the absorption line of sight. They modeled the Kunth et al. O I line for var ...
Linking Gas Fractions to Bimodalities in Galaxy Properties
... galaxies to examine the relationship of gas fractions to observed bimodalities in galaxy properties as a function of color and stellar mass. The recently identified transition in galaxy properties at stellar masses ∼ 2–3 × 1010 M⊙ corresponds to a shift in gas richness, dividing low-mass late-type g ...
... galaxies to examine the relationship of gas fractions to observed bimodalities in galaxy properties as a function of color and stellar mass. The recently identified transition in galaxy properties at stellar masses ∼ 2–3 × 1010 M⊙ corresponds to a shift in gas richness, dividing low-mass late-type g ...
Cosmological Aspects of Nucleosynthesis
... Why does <4/3 has a finite range? The decrease of below 4/3 is a consequence of the new particles which do not immediately add their contribution to the total pressure.. At high densities: >4/3, because the electron becomes more degenerate At high temperatures: >4/3 because the particles becom ...
... Why does <4/3 has a finite range? The decrease of below 4/3 is a consequence of the new particles which do not immediately add their contribution to the total pressure.. At high densities: >4/3, because the electron becomes more degenerate At high temperatures: >4/3 because the particles becom ...
Abundance of Elements
... I. Derive the stellar parameters of M dwarfs using the synthetic spectra in the long wavelength region of the optical spectra (over 8000 Å), which is relatively less contaminated by molecular lines as well as telluric lines. Test the synthetic spectrum for K2 III type star : HD 110014 ...
... I. Derive the stellar parameters of M dwarfs using the synthetic spectra in the long wavelength region of the optical spectra (over 8000 Å), which is relatively less contaminated by molecular lines as well as telluric lines. Test the synthetic spectrum for K2 III type star : HD 110014 ...
–1– 2. Milky Way We know a great deal, perhaps more than any
... Kapteyn was aware of extinction problems. He searched for these, but did not find any significant effect. However, the mistake he made was at that time he was only aware of scattering by dust particles, but he did not consider absorption, which turns out to have a much more important effect. • Shapl ...
... Kapteyn was aware of extinction problems. He searched for these, but did not find any significant effect. However, the mistake he made was at that time he was only aware of scattering by dust particles, but he did not consider absorption, which turns out to have a much more important effect. • Shapl ...
UGA Physics Colloquium - Academics
... 3-D radiation-hydrodynamic numerical simulations of the formation of HII regions in accretion flows are now possible The dense, rotating, accretion flows required to form massive stars quickly become gravitationally unstable High-resolution simulations (Peters et al. 2010a) show that when accr ...
... 3-D radiation-hydrodynamic numerical simulations of the formation of HII regions in accretion flows are now possible The dense, rotating, accretion flows required to form massive stars quickly become gravitationally unstable High-resolution simulations (Peters et al. 2010a) show that when accr ...
across
... Back in the 1850s, scientists thought the Sun's energy came from gravity- the Sun was converting gravitational energy to heat. Egrav=GMm/R. So as R get smaller, energy can be released. Lord Kelvin estimated the Sun could last 30 million years based on this. ...
... Back in the 1850s, scientists thought the Sun's energy came from gravity- the Sun was converting gravitational energy to heat. Egrav=GMm/R. So as R get smaller, energy can be released. Lord Kelvin estimated the Sun could last 30 million years based on this. ...
Why Study Cosmic Near Infrared Background? (1-4um)
... They claim that the excess near infrared background cannot originate from high-z galaxies, because such galaxies are not seen in high-z galaxy surveys. ...
... They claim that the excess near infrared background cannot originate from high-z galaxies, because such galaxies are not seen in high-z galaxy surveys. ...
NRO M33 All Disk Survey of Giant Molecular Clouds (NRO MAGiC
... regions of M33, such as the supergiant Hii region NGC 604, have also been mapped in 12 CO (J = 1–0) lines using the OVRO array (Wilson & Scoville 1989, 1990) and NMA (Miura et al. 2010), and 12 CO (J = 1–0)/12 CO (J = 3–2) multitransition maps of NGC 604 have been presented using the NRO 45-m and AS ...
... regions of M33, such as the supergiant Hii region NGC 604, have also been mapped in 12 CO (J = 1–0) lines using the OVRO array (Wilson & Scoville 1989, 1990) and NMA (Miura et al. 2010), and 12 CO (J = 1–0)/12 CO (J = 3–2) multitransition maps of NGC 604 have been presented using the NRO 45-m and AS ...
Distance Ladder
... •Typically 300 km/s or so How to to determine distances: is moving away from us at •Measure v using Doppler shift 2100 km/s? A) 1 Mly D) 484 Mly •Deduce the distance from: B) 10 Mly E) 4,840 Mly v = H0d C) 100 Mly F) 48,400 Mly ...
... •Typically 300 km/s or so How to to determine distances: is moving away from us at •Measure v using Doppler shift 2100 km/s? A) 1 Mly D) 484 Mly •Deduce the distance from: B) 10 Mly E) 4,840 Mly v = H0d C) 100 Mly F) 48,400 Mly ...
Binary Star Systems - d_smith.lhseducators.com
... type of spectroscopic binary, where the orbit of the two stars is edge-on to our line of sight. • We periodically see one star pass in front of or eclipse the other star. When this happens the total amount of light that we receive from the pair dims for a few hours. ...
... type of spectroscopic binary, where the orbit of the two stars is edge-on to our line of sight. • We periodically see one star pass in front of or eclipse the other star. When this happens the total amount of light that we receive from the pair dims for a few hours. ...
Phobos
... it from Ptolemy in his work called the ‘Algamest’ (C.151 BCE.) He in turn took it from the poetic work of Aratos called ‘The Phaenomena’ (275 BCE.) The information for his work was taken from the list of Eudoxus of Knidos (403 to 350 BC). Where it originated from is anyone’s guess, but it is certain ...
... it from Ptolemy in his work called the ‘Algamest’ (C.151 BCE.) He in turn took it from the poetic work of Aratos called ‘The Phaenomena’ (275 BCE.) The information for his work was taken from the list of Eudoxus of Knidos (403 to 350 BC). Where it originated from is anyone’s guess, but it is certain ...
B2 Star Formation and Nuclear Fusion
... In the temperature-density diagram, the star begins an adiabaticlike phase of evolution with slope 2/3 as it contracts and heats up. Fragmentation stops, liberation of gravitational potential energy drives up the temperature, and the protostar begins its life. The optically-thick phase of evolution ...
... In the temperature-density diagram, the star begins an adiabaticlike phase of evolution with slope 2/3 as it contracts and heats up. Fragmentation stops, liberation of gravitational potential energy drives up the temperature, and the protostar begins its life. The optically-thick phase of evolution ...
HR Diagram, Star Clusters, and Stellar Evolution
... • On the MS, a star is in a hydrostatic equilibrium, and its core is sufficiently hot to fuse H into He • Now the star has two chemically distinct zones, a core of inert He surrounded by an H envelope - the core of a MS star is not sufficiently hot for He burning • When the core becomes pure He, ...
... • On the MS, a star is in a hydrostatic equilibrium, and its core is sufficiently hot to fuse H into He • Now the star has two chemically distinct zones, a core of inert He surrounded by an H envelope - the core of a MS star is not sufficiently hot for He burning • When the core becomes pure He, ...
The Milky Way - Houston Community College System
... A. Luminosity, Radius, and Temperature B. The H-R Diagram C. Giants, Supergiants, and Dwarfs D. Interferometric Observations of Star Diameters E. Luminosity Classification ...
... A. Luminosity, Radius, and Temperature B. The H-R Diagram C. Giants, Supergiants, and Dwarfs D. Interferometric Observations of Star Diameters E. Luminosity Classification ...
The Milky Way - University of North Texas
... a. Giant molecular clouds do not contain enough material. b. General relativity does not allow such massive objects to exist. c. The rotation rate is so high that such an object splits into a pair of stars. d. Objects above this mass fuse hydrogen too rapidly and cannot stay together. e. Objects abo ...
... a. Giant molecular clouds do not contain enough material. b. General relativity does not allow such massive objects to exist. c. The rotation rate is so high that such an object splits into a pair of stars. d. Objects above this mass fuse hydrogen too rapidly and cannot stay together. e. Objects abo ...
Presentation
... Prialnik, Dina (2000). An Introduction to the Theory of Stellar Structure and Evolution. Cambridge University Press. Stahler, S. W. & Palla, F. (2004). The Formation of Stars. Weinheim: Wiley-VCH. ...
... Prialnik, Dina (2000). An Introduction to the Theory of Stellar Structure and Evolution. Cambridge University Press. Stahler, S. W. & Palla, F. (2004). The Formation of Stars. Weinheim: Wiley-VCH. ...
18. Formation of Stars.
... formation & evolution. ◦ Gravity is constantly trying to pull matter toward the center of mass of a gas cloud or a star. ◦ Since stars do not have an infinite supply of energy, they must readjust their structure in response to the energy supply. Initially, gravitational collapse is the only source ...
... formation & evolution. ◦ Gravity is constantly trying to pull matter toward the center of mass of a gas cloud or a star. ◦ Since stars do not have an infinite supply of energy, they must readjust their structure in response to the energy supply. Initially, gravitational collapse is the only source ...
Basic properties of stars
... 61 Cyg is also a binary star with a period of 659 yrs. Over the course of hundreds of thousands of years, the proper motions of the stars will cause the constellations to change shape. ...
... 61 Cyg is also a binary star with a period of 659 yrs. Over the course of hundreds of thousands of years, the proper motions of the stars will cause the constellations to change shape. ...
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.