Rosette Nebula - Westchester Amateur Astronomers
... sky. That leaves Mars and Saturn to keep our attention before dawn this month. We get closest to Jupiter for the year on the 8th, so for the whole month waiting until Jupiter gets high above the horizon is well worth the wait with any size telescope. If you can pick out some of Jupiter’s spots, thei ...
... sky. That leaves Mars and Saturn to keep our attention before dawn this month. We get closest to Jupiter for the year on the 8th, so for the whole month waiting until Jupiter gets high above the horizon is well worth the wait with any size telescope. If you can pick out some of Jupiter’s spots, thei ...
Lecture101602
... K = 0 is absolute zero, the coldest temperature possible K = 273 is the freezing point of water (32 oF) K = 373 is the boiling point of water (212 oF) ...
... K = 0 is absolute zero, the coldest temperature possible K = 273 is the freezing point of water (32 oF) K = 373 is the boiling point of water (212 oF) ...
n - Ira-Inaf
... as atoms & molecules (cold) ions +electrons (hot) average number density = 1 cm3 quantum processes then line emission/absorption ~80% of the interstellar space filled with cold, high d ...
... as atoms & molecules (cold) ions +electrons (hot) average number density = 1 cm3 quantum processes then line emission/absorption ~80% of the interstellar space filled with cold, high d ...
STAR TYPES
... As stars begin to die, they become giants and supergiants (above the main sequence). These stars have depleted their hydrogen supply and are very old. The core contracts as the outer layers expand. These stars will eventually explode (becoming a planetary nebula or supernova, depending on their mass ...
... As stars begin to die, they become giants and supergiants (above the main sequence). These stars have depleted their hydrogen supply and are very old. The core contracts as the outer layers expand. These stars will eventually explode (becoming a planetary nebula or supernova, depending on their mass ...
Presentation - University of Idaho
... A main-sequence star cannot maintain equilibrium if more than 10% of its total mass has been converted into Helium ...
... A main-sequence star cannot maintain equilibrium if more than 10% of its total mass has been converted into Helium ...
UNIVERSITY OF BRISTOL
... Consider a uniformly mixed `slab' of stars and dust of physical thickness X and total optical depth . If is the emissivity per unit volume of the stars, write down the observed intensity (outside the slab) from a volume element of thickness dx a distance x into the cloud. Hence, by integration, s ...
... Consider a uniformly mixed `slab' of stars and dust of physical thickness X and total optical depth . If is the emissivity per unit volume of the stars, write down the observed intensity (outside the slab) from a volume element of thickness dx a distance x into the cloud. Hence, by integration, s ...
Weighing a Galaxy—11 Nov Ast 207 F2005 Nov-09 • Schedule
... 1. What are the fossils (something that can be examined) from the universe at 3 min? 2. The amount of helium in the sun depends on the properties of deuterium. If deuterium is less tightly bound, would there be more or less helium on the surface of the sun? ...
... 1. What are the fossils (something that can be examined) from the universe at 3 min? 2. The amount of helium in the sun depends on the properties of deuterium. If deuterium is less tightly bound, would there be more or less helium on the surface of the sun? ...
Exercise 5
... 2. Using an appropriate diagram in your textbook, label the various areas of your diagram that classify the various stars. Introduction to spectroscopy You’ve now seen that stars seem to group into various parts of the Hertzsprung-Russell diagram. The next step is to ask “Why do they do that?”, whic ...
... 2. Using an appropriate diagram in your textbook, label the various areas of your diagram that classify the various stars. Introduction to spectroscopy You’ve now seen that stars seem to group into various parts of the Hertzsprung-Russell diagram. The next step is to ask “Why do they do that?”, whic ...
phys-1600 - Dave Heppenstall
... • In Io's case, there are immense volcanoes which are constantly being churned inside out and renewing its surface. This is due to the close proximity to Jupiter and the enormous gravitational force. • Io has no atmosphere. If Io moves in closer to Jupiter, it could be torn apart. Io is also in an e ...
... • In Io's case, there are immense volcanoes which are constantly being churned inside out and renewing its surface. This is due to the close proximity to Jupiter and the enormous gravitational force. • Io has no atmosphere. If Io moves in closer to Jupiter, it could be torn apart. Io is also in an e ...
Slide 1
... formed at the same time and composition, from the evolution of stars in the cluster with different masses isochrones • High mass stars evolve off the MS (“turn off”) before low mass stars ...
... formed at the same time and composition, from the evolution of stars in the cluster with different masses isochrones • High mass stars evolve off the MS (“turn off”) before low mass stars ...
Kinematics of Arp 270: gas flows, nuclear activity
... which is important in determining how the stars form, so that if we have sets of placental clouds with different density regimes we might well expect distinct star formation regimes within them. We have initiated a programme of kinematic observations of interacting galaxy pairs analysing the Hα emis ...
... which is important in determining how the stars form, so that if we have sets of placental clouds with different density regimes we might well expect distinct star formation regimes within them. We have initiated a programme of kinematic observations of interacting galaxy pairs analysing the Hα emis ...
elementary measuring stars
... The proper motion of a star refers to its annual displacement in the sky relative to a fixed coordinate grid. Proper motion angles are much larger than parallax angles. ...
... The proper motion of a star refers to its annual displacement in the sky relative to a fixed coordinate grid. Proper motion angles are much larger than parallax angles. ...
White Dwarfs
... Eventually at ρ greater than about 10 7 g cm −3 electrons in the central part of the white dwarf start to move close to the speed of light. As the mass continues to grow, a larger fraction of the star is supported by relativistic electron degeneracy pressure. Consider the limit: GM ρ ...
... Eventually at ρ greater than about 10 7 g cm −3 electrons in the central part of the white dwarf start to move close to the speed of light. As the mass continues to grow, a larger fraction of the star is supported by relativistic electron degeneracy pressure. Consider the limit: GM ρ ...
Stars in Their Youth
... is that they are converting hydrogen into helium in their cores. In the Chap. 1 we outlined the extraordinary conjecture by Eddington. But it took nearly twenty years to work out the details. The first breakthrough in solving the problem of how stars liberate energy came in 1938 when C. F. von Weizs ...
... is that they are converting hydrogen into helium in their cores. In the Chap. 1 we outlined the extraordinary conjecture by Eddington. But it took nearly twenty years to work out the details. The first breakthrough in solving the problem of how stars liberate energy came in 1938 when C. F. von Weizs ...
Chapter 14. Stellar Structure and Evolution
... Inevitably a star will exhaust the H in its core, having converted it to He. The Sun is about half way through that process. In the core of the Sun, we believe the present composition is about 50% He. As the He is created, the core of the star must move to slightly higher temperatures and pressures ...
... Inevitably a star will exhaust the H in its core, having converted it to He. The Sun is about half way through that process. In the core of the Sun, we believe the present composition is about 50% He. As the He is created, the core of the star must move to slightly higher temperatures and pressures ...
A Reservoir of Ionized Gas in the Galactic Halo to Sustain Star
... iHVCs were found within 8–15 kpc from the sun (17, 18). One of them was found toward the inner Galaxy and has super-solar metallicity, probing gas that has been ejected from and is raining back onto the Milky Way disk (17). Another was observed at l ∼ 103◦ with a galactocentric distance of < 17.7 kp ...
... iHVCs were found within 8–15 kpc from the sun (17, 18). One of them was found toward the inner Galaxy and has super-solar metallicity, probing gas that has been ejected from and is raining back onto the Milky Way disk (17). Another was observed at l ∼ 103◦ with a galactocentric distance of < 17.7 kp ...
Article PDF - IOPscience
... components in this galaxy from the spectroscopy alone. The methodologically independent discovery of two distinct stellar components in CVn I from the LBC photometry and the much smaller extent of the young population surprisingly recalls their findings. A direct comparison of their spectroscopic sa ...
... components in this galaxy from the spectroscopy alone. The methodologically independent discovery of two distinct stellar components in CVn I from the LBC photometry and the much smaller extent of the young population surprisingly recalls their findings. A direct comparison of their spectroscopic sa ...
Star A
... In a double-line spectroscopic binary, two distinct sets of spectral lines—one for each component star—shift back and forth as the stars move. Because we see particular lines alternately approaching and receding, we know that the objects emitting the lines are in orbit. Media Clip In the more commo ...
... In a double-line spectroscopic binary, two distinct sets of spectral lines—one for each component star—shift back and forth as the stars move. Because we see particular lines alternately approaching and receding, we know that the objects emitting the lines are in orbit. Media Clip In the more commo ...
what are stars made of?
... A graph called a Hertzsprung–Russell diagram helps astronomers to place stars into particular groups. This is done by plotting a star’s brightness against its temperature, as well as noting its colour. ...
... A graph called a Hertzsprung–Russell diagram helps astronomers to place stars into particular groups. This is done by plotting a star’s brightness against its temperature, as well as noting its colour. ...
Star Clusters and their stars
... They typically have 105 – 106 stars. They are spherically distributed around the center of our Galaxy. They tend to concentrate towards the center of the Galaxy, with many in the constellations Sagittarius, Scorpio and Ophiunchus It was by studying the distribution of globular clusters that astronom ...
... They typically have 105 – 106 stars. They are spherically distributed around the center of our Galaxy. They tend to concentrate towards the center of the Galaxy, with many in the constellations Sagittarius, Scorpio and Ophiunchus It was by studying the distribution of globular clusters that astronom ...
Star_Clusters
... They typically have 105 – 106 stars. They are spherically distributed around the center of our Galaxy. They tend to concentrate towards the center of the Galaxy, with many in the constellations Sagittarius, Scorpio and Ophiunchus It was by studying the distribution of globular clusters that astronom ...
... They typically have 105 – 106 stars. They are spherically distributed around the center of our Galaxy. They tend to concentrate towards the center of the Galaxy, with many in the constellations Sagittarius, Scorpio and Ophiunchus It was by studying the distribution of globular clusters that astronom ...
The Universe - the Scientia Review
... classified as elliptical. Because of their brightness, we usually can’t see any features in these galaxies. Some elliptical galaxies have only a hundred million stars, while others contain as many as one trillion stars, most of This picture of the M87 galaxy clearly which are older and shows the bri ...
... classified as elliptical. Because of their brightness, we usually can’t see any features in these galaxies. Some elliptical galaxies have only a hundred million stars, while others contain as many as one trillion stars, most of This picture of the M87 galaxy clearly which are older and shows the bri ...
Measuring colour in astronomy
... Many of the galaxies imaged by SDSS are too far away to make out individual features, so one has to measure the spectrum and colour of a whole galaxy. Since the light from a galaxy is just the sum of all the light from the individual stars of which it is made, its spectrum – and hence its colour – i ...
... Many of the galaxies imaged by SDSS are too far away to make out individual features, so one has to measure the spectrum and colour of a whole galaxy. Since the light from a galaxy is just the sum of all the light from the individual stars of which it is made, its spectrum – and hence its colour – i ...
The Stellar Population And Origin Of The Mysterious K.V. Getman
... The mysterious high galactic latitude cometary globule (CG) CG12 has been observed with the ACIS detector on board the Chandra X-ray Observatory. We detect 128 X-ray sources, of which a half are likely young stars formed within the globule's head. This new population of >=50 T-Tauri stars and one ne ...
... The mysterious high galactic latitude cometary globule (CG) CG12 has been observed with the ACIS detector on board the Chandra X-ray Observatory. We detect 128 X-ray sources, of which a half are likely young stars formed within the globule's head. This new population of >=50 T-Tauri stars and one ne ...
Chapter 11: Stars
... temperature can only be inferred from models. • Surface T is easier to measure than its luminosity because it does not depend on distance. ...
... temperature can only be inferred from models. • Surface T is easier to measure than its luminosity because it does not depend on distance. ...
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.