Word doc - UC-HiPACC - University of California, Santa Cruz
... Today, the highest-mass stars top out at about 100 solar masses (Eta Carinae, one of the most massive stars in our Milky Way galaxy, is about 90). But recent cosmological simulations suggest the possibility that in the early universe truly gargantuan stars could exist. So Chen began exploring this w ...
... Today, the highest-mass stars top out at about 100 solar masses (Eta Carinae, one of the most massive stars in our Milky Way galaxy, is about 90). But recent cosmological simulations suggest the possibility that in the early universe truly gargantuan stars could exist. So Chen began exploring this w ...
Sirius Astronomer - Orange County Astronomers
... Galaxy merging – Two young galaxies that collided 11 billion years ago (but so distant that we are just seeing them now) are seen to be rapidly forming a massive galaxy about 10 times the size of our Milky Way. The new mega galaxy is the brightest most gas-rich galaxy merger ever seen in submillimet ...
... Galaxy merging – Two young galaxies that collided 11 billion years ago (but so distant that we are just seeing them now) are seen to be rapidly forming a massive galaxy about 10 times the size of our Milky Way. The new mega galaxy is the brightest most gas-rich galaxy merger ever seen in submillimet ...
Balmer lines
... Rutherford fired alpha particles at a very thin sheet of gold, and found that gold atoms must consist of a very small nucleus containing most of the mass. ...
... Rutherford fired alpha particles at a very thin sheet of gold, and found that gold atoms must consist of a very small nucleus containing most of the mass. ...
Physics - Content by Unit
... time less than an orbital period, most of the mass points would collapse to a bar-shaped, dense concentration close to the center of the galaxy with only a few mass points at larger radii. This looked nothing like the elegant spiral or elliptical shapes we are used to seeing. However, if they added ...
... time less than an orbital period, most of the mass points would collapse to a bar-shaped, dense concentration close to the center of the galaxy with only a few mass points at larger radii. This looked nothing like the elegant spiral or elliptical shapes we are used to seeing. However, if they added ...
The Milky Way as a Galaxy, Galaxy Classification
... • B/D ratio ---> spheroid/disk mass fractions • pitch angle ---> rotation curve of disk, mass concentration • resolution ---> star formation rate ...
... • B/D ratio ---> spheroid/disk mass fractions • pitch angle ---> rotation curve of disk, mass concentration • resolution ---> star formation rate ...
astronomy timeline
... Arno Penzias and Robert Wilson discoverd cosmic background radiation. Penzias and Wilson used a radio telescope to detect the highly redshifted radiation from the early stages in the expansion of the universe. p. 521-522, F 17.7, 17.8 ...
... Arno Penzias and Robert Wilson discoverd cosmic background radiation. Penzias and Wilson used a radio telescope to detect the highly redshifted radiation from the early stages in the expansion of the universe. p. 521-522, F 17.7, 17.8 ...
_____ 1. Which of the following statements is NOT true about stars
... a. A star begins its life as a ball of gas and dust. b. As stars get older, they lose some of their material. c. Stars last forever. d. New stars form from the material of old stars. 2. During a star’s life cycle, hydrogen changes to helium in a process called __________________ __________________. ...
... a. A star begins its life as a ball of gas and dust. b. As stars get older, they lose some of their material. c. Stars last forever. d. New stars form from the material of old stars. 2. During a star’s life cycle, hydrogen changes to helium in a process called __________________ __________________. ...
Lecture 5: Stars
... We only know the absolute luminosity if we know the distance, but we only know the parallax distances out to about 100 pc (further to some bright stars). The problem is that if we see a star with a surface temperature of 3000K – is it a nearby red dwarf, or a distant red giant? Without more informat ...
... We only know the absolute luminosity if we know the distance, but we only know the parallax distances out to about 100 pc (further to some bright stars). The problem is that if we see a star with a surface temperature of 3000K – is it a nearby red dwarf, or a distant red giant? Without more informat ...
Chapter 31 Galaxies & the Universe
... The Shape of the Milky Way Astronomers have determined the shape of the Milky Way by using radio waves because they penetrate the interstellar gas and dust without being scattered or absorbed. ...
... The Shape of the Milky Way Astronomers have determined the shape of the Milky Way by using radio waves because they penetrate the interstellar gas and dust without being scattered or absorbed. ...
The Death of a Low Mass Star
... Evolution of a sun-like star post heliumflash – The star moves onto the horizontal branch of the Hertzprung-Russell diagram – Helium burning produces carbon and oxygen “ash” – Eventually, the helium concentration falls too low to sustain burning in the core ...
... Evolution of a sun-like star post heliumflash – The star moves onto the horizontal branch of the Hertzprung-Russell diagram – Helium burning produces carbon and oxygen “ash” – Eventually, the helium concentration falls too low to sustain burning in the core ...
The Life of a Star
... As it shrinks, it grows hotter and denser, and a new series of nuclear reactions, temporarily halting the collapse The core becomes essentially just iron, (because of iron's nuclear structure, it does not permit its atoms to fuse into heavier elements) and fusion ceases. In less than a second, ...
... As it shrinks, it grows hotter and denser, and a new series of nuclear reactions, temporarily halting the collapse The core becomes essentially just iron, (because of iron's nuclear structure, it does not permit its atoms to fuse into heavier elements) and fusion ceases. In less than a second, ...
Unit 1 - UW Madison Astronomy Department
... What causes the core of a s tar to contract during the main sequence phase of the star’s life? a. Helium has a larger atomic weight than hydrogen and exerts a stronger gravitational pull on the core. b. Convection in the outer layers carries energy out of the core more efficiently as the star ages c ...
... What causes the core of a s tar to contract during the main sequence phase of the star’s life? a. Helium has a larger atomic weight than hydrogen and exerts a stronger gravitational pull on the core. b. Convection in the outer layers carries energy out of the core more efficiently as the star ages c ...
This document was created for people who do not have access to
... of our Milky Way galaxy. As we leave the Milky Way, we find ourselves in a universe filled with billions of galaxies. Because the light from distant galaxies takes vast amounts of time to reach our telescopes here on Earth, we see these galaxies as they looked in the past, when the universe was very ...
... of our Milky Way galaxy. As we leave the Milky Way, we find ourselves in a universe filled with billions of galaxies. Because the light from distant galaxies takes vast amounts of time to reach our telescopes here on Earth, we see these galaxies as they looked in the past, when the universe was very ...
1. Stellar Evolution – Notes Astronomers classify stars according to
... bottom and gets brighter towards the top. This places the cooler, dimmer stars towards the lower right and the hotter, more luminous stars at the upper left. Our own star, the Sun, is nearly in the middle of both the temperature and luminosity scales relative to other stars. This puts it around the ...
... bottom and gets brighter towards the top. This places the cooler, dimmer stars towards the lower right and the hotter, more luminous stars at the upper left. Our own star, the Sun, is nearly in the middle of both the temperature and luminosity scales relative to other stars. This puts it around the ...
Microsoft Power Point version
... For Example, Deneb has a luminosity of 170,000 times the luminosity of the sun. Its spectral type is A2, which means its temp is about 10,000 Kelvin (remember the sun;s temp is 5800 kelvin). ...
... For Example, Deneb has a luminosity of 170,000 times the luminosity of the sun. Its spectral type is A2, which means its temp is about 10,000 Kelvin (remember the sun;s temp is 5800 kelvin). ...
Galaxy Evolution
... galaxies have a higher fraction of spirals than nearby clusters • Distant clusters contain more galaxies within a given volume • Distant galaxies show more signs of disturbance by neighboring galaxies (odd shapes, bent arms, twisted disks) ...
... galaxies have a higher fraction of spirals than nearby clusters • Distant clusters contain more galaxies within a given volume • Distant galaxies show more signs of disturbance by neighboring galaxies (odd shapes, bent arms, twisted disks) ...
Properties of Stars in general
... the intensity of different lines varies with spectral type (and hence with temperature). ...
... the intensity of different lines varies with spectral type (and hence with temperature). ...
Signatures of the first stars in the 21cm Emission and Absorption
... • Each metal-free star can produce about 105 ionizing photons per baryon it contains, creating an HII region of ~ 107 Msun of gas, of physical radius ~ 1 kpc at z=30. Probably only one metal-free star forms per halo. • Star formation occurring after the HII region recombines and merges is probably f ...
... • Each metal-free star can produce about 105 ionizing photons per baryon it contains, creating an HII region of ~ 107 Msun of gas, of physical radius ~ 1 kpc at z=30. Probably only one metal-free star forms per halo. • Star formation occurring after the HII region recombines and merges is probably f ...
Galaxy Notes
... from the central bulge. The Milky Way is a spiral galaxy. Like pinwheels, all spiral galaxies rotate -- but slowly. The Milky Way, for example, makes a complete revolution once every 250 million years or so. New stars are constantly forming out of gas and dust in spiral galaxies. Smaller groups of s ...
... from the central bulge. The Milky Way is a spiral galaxy. Like pinwheels, all spiral galaxies rotate -- but slowly. The Milky Way, for example, makes a complete revolution once every 250 million years or so. New stars are constantly forming out of gas and dust in spiral galaxies. Smaller groups of s ...
Patterns in the Sky - Plano Independent School District
... winter months. It has 2 of the sky’s 15 brightest stars. The deep red star Betelgeuse. This star shrinks and swells over a cycle of six months. The second star is Rigel which is 900 light years away from Earth. Orion’s belt is formed by 3 stars and hanging from the belt is a sword. About halfway dow ...
... winter months. It has 2 of the sky’s 15 brightest stars. The deep red star Betelgeuse. This star shrinks and swells over a cycle of six months. The second star is Rigel which is 900 light years away from Earth. Orion’s belt is formed by 3 stars and hanging from the belt is a sword. About halfway dow ...
Galaxy interaction and transformation
... simulations are used to understand the properties of merger remnants. Some of the most important results obtained are 1. Major mergers of galaxies generally lead to elliptical-like remnants, with some irregular structures in the outer regions. Depending on the orbital geometry of the merger, the rem ...
... simulations are used to understand the properties of merger remnants. Some of the most important results obtained are 1. Major mergers of galaxies generally lead to elliptical-like remnants, with some irregular structures in the outer regions. Depending on the orbital geometry of the merger, the rem ...
Supernovae – the biggest bangs since the Big Bang
... If you know the apparent brightness of a star and you know the intrinsic brightness of the star, you can determine how far away the star is. During the 1990's two groups of astronomers endeavored to discover Type Ia supernovae as far away as possible. They found some objects so far away that their ...
... If you know the apparent brightness of a star and you know the intrinsic brightness of the star, you can determine how far away the star is. During the 1990's two groups of astronomers endeavored to discover Type Ia supernovae as far away as possible. They found some objects so far away that their ...
Stability and formation of the fractal
... The triggering of star formation could be due to un-balanced time-scales Pertubation is a non-linear increase of velocity dispersion, due for instance to galaxy encounters These trigger collisions => either coalescence, or shredding and increase of ΔV If there is a time-delay between the formation t ...
... The triggering of star formation could be due to un-balanced time-scales Pertubation is a non-linear increase of velocity dispersion, due for instance to galaxy encounters These trigger collisions => either coalescence, or shredding and increase of ΔV If there is a time-delay between the formation t ...
Lecture 31
... sources) and found its distance from its redshift to be 2 billion light years--not a star, and L = 1040 watts--1,000 L (MW)!! .8 to 14(?) Billion years--distance range. L = 1038-1042 watts. Energy comes from a region solar system-sized. Radio Jets. A thermal (synchotron) and non-thermal (black-body) ...
... sources) and found its distance from its redshift to be 2 billion light years--not a star, and L = 1040 watts--1,000 L (MW)!! .8 to 14(?) Billion years--distance range. L = 1038-1042 watts. Energy comes from a region solar system-sized. Radio Jets. A thermal (synchotron) and non-thermal (black-body) ...
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.