ASTR 1020 Homework Solutions
... elongation than vice versa because the orbital distance is greater, as can be seen in Figure 4-6. This can be verified with the dates, too, e.g., February 24 to April 8 is 43 days, while April 8 to June 20 is 73 days. 39. Since the comet orbits the Sun, you may use Kepler's 3rd law, P2 = a3, where P ...
... elongation than vice versa because the orbital distance is greater, as can be seen in Figure 4-6. This can be verified with the dates, too, e.g., February 24 to April 8 is 43 days, while April 8 to June 20 is 73 days. 39. Since the comet orbits the Sun, you may use Kepler's 3rd law, P2 = a3, where P ...
key - Scioly.org
... B0IVe. Which of the following inferences about the two stars is incorrect? [2] (a) Cygnus OB2-12 is younger than Gamma Cassiopeiea (b) Cygnus OB2-12 is a variable star, whereas Gamma Cassiopeiea is not (c) Gamma Cassiopeiea has a circumstellar disk, while Cygnus OB2-12 does not (d) Gamma Cassiopeiea ...
... B0IVe. Which of the following inferences about the two stars is incorrect? [2] (a) Cygnus OB2-12 is younger than Gamma Cassiopeiea (b) Cygnus OB2-12 is a variable star, whereas Gamma Cassiopeiea is not (c) Gamma Cassiopeiea has a circumstellar disk, while Cygnus OB2-12 does not (d) Gamma Cassiopeiea ...
Document
... • We measure the orbits of fast-moving stars near the Galactic center. • these measurements must be made in the infrared • in particular, this star passed within 1 light-day of Sgr A* • using Kepler’s Law, we infer a mass of 2.6 million M for Sgr A* ...
... • We measure the orbits of fast-moving stars near the Galactic center. • these measurements must be made in the infrared • in particular, this star passed within 1 light-day of Sgr A* • using Kepler’s Law, we infer a mass of 2.6 million M for Sgr A* ...
11.1 Introduction
... enormous complexes of dust and gas, sufficiently dense to be self-shielding from the diffuse interstellar ultraviolet radiation field. Typical parameters are temperatures T ∼ 15 K, volume densities n = 100–300 cm−3 , and masses M = 105 –106 M . The low temperatures and high densities (and the prese ...
... enormous complexes of dust and gas, sufficiently dense to be self-shielding from the diffuse interstellar ultraviolet radiation field. Typical parameters are temperatures T ∼ 15 K, volume densities n = 100–300 cm−3 , and masses M = 105 –106 M . The low temperatures and high densities (and the prese ...
Homework #7 (Ch. 19)
... What do star clusters and associations have to do with star formation? 10. Chaisson Review and Discussion 19.18 Compare and contrast the observed properties of open star clusters and globular star clusters. 11. Chaisson Review and Discussion 19.19 How can we tell whether a star cluster is young or o ...
... What do star clusters and associations have to do with star formation? 10. Chaisson Review and Discussion 19.18 Compare and contrast the observed properties of open star clusters and globular star clusters. 11. Chaisson Review and Discussion 19.19 How can we tell whether a star cluster is young or o ...
Observational properties of stars
... light. And there was hydrogen in the spectrum, which indicated this to be a type II SN, actually a type IIP. The spectrum of SN1987A also showed relatively high amounts of helium, which indicate that it lost quite a bit of its hydrogen atmosphere before the supernova event. The temperature of the SN ...
... light. And there was hydrogen in the spectrum, which indicated this to be a type II SN, actually a type IIP. The spectrum of SN1987A also showed relatively high amounts of helium, which indicate that it lost quite a bit of its hydrogen atmosphere before the supernova event. The temperature of the SN ...
Stellar Populations of Galaxies- 2 Lectures H
... • Historically specific stellar absorption features over narrow wavelength intervals were used when analyzing galaxy spectra to obtain the ages and metallicities of the stellar populations • For galaxies with old stellar populations, the Lick/IDS system of ~25 narrow-band indices is often used (Wor ...
... • Historically specific stellar absorption features over narrow wavelength intervals were used when analyzing galaxy spectra to obtain the ages and metallicities of the stellar populations • For galaxies with old stellar populations, the Lick/IDS system of ~25 narrow-band indices is often used (Wor ...
1. INTRODUCTION 2. THE MODEL
... C. Hayashi prescribed a ““ minimum-mass solar nebula,ÏÏ which contained just enough material to make the planets. This prescription, which has been widely used in constructing scenarios for planet formation, proposed that ice will condense when the temperature falls below 170 K (the ““ snow line ÏÏ) ...
... C. Hayashi prescribed a ““ minimum-mass solar nebula,ÏÏ which contained just enough material to make the planets. This prescription, which has been widely used in constructing scenarios for planet formation, proposed that ice will condense when the temperature falls below 170 K (the ““ snow line ÏÏ) ...
black hole
... discussion. The gas that is expelled from these giant stars gives visible evidence that sunlike stars have gone through these stages of nucleosynthesis and do indeed die in this way. ...
... discussion. The gas that is expelled from these giant stars gives visible evidence that sunlike stars have gone through these stages of nucleosynthesis and do indeed die in this way. ...
Using AO to Measure the Star Formation Histories of Massive Galaxies
... To calculate the effects of crowding on magnitudes and colors, we need only consider the Poisson statistics of the luminosity functions (e.g. Tonry & Schneider 1988) hi ...
... To calculate the effects of crowding on magnitudes and colors, we need only consider the Poisson statistics of the luminosity functions (e.g. Tonry & Schneider 1988) hi ...
Strongly Interacting Supernovae - The National Centre for Radio
... Column density is a factor 50 smaller (1.3E21) than needed to produce the X-ray luminosity (4E22). ...
... Column density is a factor 50 smaller (1.3E21) than needed to produce the X-ray luminosity (4E22). ...
STELLAR FORMATION AND EVOLUTION
... To be able to understand the life cycle of a star, you need a good understanding of the Hertzsprung-Russell Diagram. In 1905, two astronomers, Einar Hertzsprung and Henry Norris Russell, independently plotted the temperature of a star versus the brightness of the star. They did this with a large num ...
... To be able to understand the life cycle of a star, you need a good understanding of the Hertzsprung-Russell Diagram. In 1905, two astronomers, Einar Hertzsprung and Henry Norris Russell, independently plotted the temperature of a star versus the brightness of the star. They did this with a large num ...
Neutron Density and Neutron Source Determination in Barium
... and decided to find out what this was about. First I asked some of my colleagues about Fontenelle, but none of them seemed to know him. "At which observatory does he work?" was one of the kind, but not very helpful replies. Calling the Bavarian State Library in Munich, Ilearned that no less than thr ...
... and decided to find out what this was about. First I asked some of my colleagues about Fontenelle, but none of them seemed to know him. "At which observatory does he work?" was one of the kind, but not very helpful replies. Calling the Bavarian State Library in Munich, Ilearned that no less than thr ...
DTU 8e Chap 17 Quasars and Other Active Galaxies
... An active galaxy is an extremely luminous galaxy that has one or more unusual features: an unusually bright, starlike nucleus; strong emission lines in its spectrum; rapid variations in luminosity; and jets or beams of radiation that emanate from its core. Active galaxies include quasars, Seyfert ga ...
... An active galaxy is an extremely luminous galaxy that has one or more unusual features: an unusually bright, starlike nucleus; strong emission lines in its spectrum; rapid variations in luminosity; and jets or beams of radiation that emanate from its core. Active galaxies include quasars, Seyfert ga ...
Word Document - Montana State University Extended
... Scientists generally agree that the Earth formed about 4.5 billion years ago yet complex life has existed on the Earth for about the last 500 million years. It is still unclear exactly what chain of events lead up to the emergence of complex life on this planet. One of the factors that scientists be ...
... Scientists generally agree that the Earth formed about 4.5 billion years ago yet complex life has existed on the Earth for about the last 500 million years. It is still unclear exactly what chain of events lead up to the emergence of complex life on this planet. One of the factors that scientists be ...
Milky Way I
... • The Milky Way is a spiral galaxy • The Galaxy is shaped like a disk • The Sun is located at the inner edge of a spiral arm about 2/3 of the way out from the center to the edge • The main components of the Galaxy are the disk, the bulge, and the halo • We can measure the mass of the Galaxy from the ...
... • The Milky Way is a spiral galaxy • The Galaxy is shaped like a disk • The Sun is located at the inner edge of a spiral arm about 2/3 of the way out from the center to the edge • The main components of the Galaxy are the disk, the bulge, and the halo • We can measure the mass of the Galaxy from the ...
Stellar Evolution : The Life and Death of Our Luminous Neighbors
... event horizon - The location around a black hole where the escape velocity equals the speed of light; the surface of a black hole fusion - combination of lower mass nuclides into higher mass nuclides helium flash - The nearly explosive beginning of helium burning in the dense core of a red giant sta ...
... event horizon - The location around a black hole where the escape velocity equals the speed of light; the surface of a black hole fusion - combination of lower mass nuclides into higher mass nuclides helium flash - The nearly explosive beginning of helium burning in the dense core of a red giant sta ...
The Stellar Population And Origin Of The Mysterious K.V. Getman
... located at high-galactic latitude. The existence of any star forming dark cloud at Galactic location (l,b)=(316,21) is unusual, and the cometary structure of CG12 in such an isolated environment is even more mysterious. There are no reported luminous OB-type stars at even higher latitudes to produce ...
... located at high-galactic latitude. The existence of any star forming dark cloud at Galactic location (l,b)=(316,21) is unusual, and the cometary structure of CG12 in such an isolated environment is even more mysterious. There are no reported luminous OB-type stars at even higher latitudes to produce ...
white dwarf
... Polars: Synchronisation • All of the variability in Polars occurs at a single period: the orbital period – radial velocity curves of the secondary – X-ray light curves from the primary – polarisation variations the white dwarf/red dwarf are locked into the same orientation: synchronised rotation ...
... Polars: Synchronisation • All of the variability in Polars occurs at a single period: the orbital period – radial velocity curves of the secondary – X-ray light curves from the primary – polarisation variations the white dwarf/red dwarf are locked into the same orientation: synchronised rotation ...
New Astrophysical Opportunities Exploiting Spatio-Temporal Optical Correlations
... that at least 60 Cepheids are visually brighter than 8m . Rapidly rotating stars and hot stars As a group, classical Be stars are particularly wellknown for their close to break-up rotational velocities as deduced from photospheric absorption lines. In addition the stars show Balmer line emission f ...
... that at least 60 Cepheids are visually brighter than 8m . Rapidly rotating stars and hot stars As a group, classical Be stars are particularly wellknown for their close to break-up rotational velocities as deduced from photospheric absorption lines. In addition the stars show Balmer line emission f ...
A Legacy Study of Stellar Life Cycles in the Galactic Center
... • Microquasars and some pulsars might have required luminosity and hard spectrum in high state • Fluorescent line seen in Sgr B2, Sgr C, and central parsecs of Galaxy, so would need multiple microquasars, such as GRS 1915+10, but none of them would currently be bright. • Need sources that are bright ...
... • Microquasars and some pulsars might have required luminosity and hard spectrum in high state • Fluorescent line seen in Sgr B2, Sgr C, and central parsecs of Galaxy, so would need multiple microquasars, such as GRS 1915+10, but none of them would currently be bright. • Need sources that are bright ...
A Universe of Galaxies - Pennsylvania State University
... do not produce much radio emission). They were named quasistellar radio sources (quasars, or QSOs): ...
... do not produce much radio emission). They were named quasistellar radio sources (quasars, or QSOs): ...
Cygnus X-1
Cygnus X-1 (abbreviated Cyg X-1) is a well-known galactic X-ray source, thought to be a black hole, in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 6977229999999999999♠2.3×10−23 Wm−2 Hz−1 (7003230000000000000♠2.3×103 Jansky). Cygnus X-1 was the first X-ray source widely accepted to be a black hole and it remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any known kind of normal star, or other likely object besides a black hole. If so, the radius of its event horizon is about 7004440000000000000♠44 km.Cygnus X-1 belongs to a high-mass X-ray binary system about 7019574266339685654♠6070 ly from the Sun that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicular to the disk, are carrying part of the energy of the infalling material away into interstellar space.This system may belong to a stellar association called Cygnus OB3, which would mean that Cygnus X-1 is about five million years old and formed from a progenitor star that had more than 7001400000000000000♠40 solar masses. The majority of the star's mass was shed, most likely as a stellar wind. If this star had then exploded as a supernova, the resulting force would most likely have ejected the remnant from the system. Hence the star may have instead collapsed directly into a black hole.Cygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.