AST 301 Introduction to Astronomy - University of Texas Astronomy
... because the protons must be moving fast to get close enough together so they can be attracted by the strong force before their electrical repulsion pushes them apart. If the center of a star is too hot, fusion will run faster than energy is being radiated from the surface. But the high temperature w ...
... because the protons must be moving fast to get close enough together so they can be attracted by the strong force before their electrical repulsion pushes them apart. If the center of a star is too hot, fusion will run faster than energy is being radiated from the surface. But the high temperature w ...
Microsoft Word
... age spread of ~0.5-5 Myr with an average age of ~ 2-3 Myr, suggesting noncoeval star formation in NGC 1624. The NIR excess fraction on the basis of JHK data is found to be ~20% which indicates an average age ~2-3 Myr for YSOs. From the radio continuum flux, spectral type of the ionizing source of th ...
... age spread of ~0.5-5 Myr with an average age of ~ 2-3 Myr, suggesting noncoeval star formation in NGC 1624. The NIR excess fraction on the basis of JHK data is found to be ~20% which indicates an average age ~2-3 Myr for YSOs. From the radio continuum flux, spectral type of the ionizing source of th ...
PPT 15MB - HubbleSOURCE
... image, however, about 0.4 degrees across in panel “b”) The Paschen series of hydrogen spectral lines in the infrared is named after the German physicist Louis Paschen, who discovered them in 1908 (the alpha line, at 1.87 microns, is the strongest of the series). The Earth’s atmosphere absorbs this ...
... image, however, about 0.4 degrees across in panel “b”) The Paschen series of hydrogen spectral lines in the infrared is named after the German physicist Louis Paschen, who discovered them in 1908 (the alpha line, at 1.87 microns, is the strongest of the series). The Earth’s atmosphere absorbs this ...
Astronomy 1001/1005 Final Exam (250 points)
... You will NOT get your bubble sheet back One page of notes is allowed Use a #2 pencil on the bubble sheet. Make your bubbles dark and neat. There are 50 multiple choice problems and your choice of 5 short answer questions with point values given for each. ...
... You will NOT get your bubble sheet back One page of notes is allowed Use a #2 pencil on the bubble sheet. Make your bubbles dark and neat. There are 50 multiple choice problems and your choice of 5 short answer questions with point values given for each. ...
The Death of Massive Stars
... most with periods between 0.1 and 4 seconds. • The Crab pulsar spins so rapidly because it formed so recently. Over time it will lose rotational energy, slow down, and emit less energy. • The Crab pulsar is slowing down because of the “drag” of the electrons propelled out into the nebula surrounding ...
... most with periods between 0.1 and 4 seconds. • The Crab pulsar spins so rapidly because it formed so recently. Over time it will lose rotational energy, slow down, and emit less energy. • The Crab pulsar is slowing down because of the “drag” of the electrons propelled out into the nebula surrounding ...
A neutron star with a carbon atmosphere in the Cassiopeia A
... well as our carbon model fit. We fitted the Hwang and Pavlov data simultaneously with several models: a blackbody, a H atmosphere,13 and atmospheres composed of pure He, C, N, or O; these are illustrated in Fig. 2. To identify promising models, the mass and radius of the atmosphere models were fixed ...
... well as our carbon model fit. We fitted the Hwang and Pavlov data simultaneously with several models: a blackbody, a H atmosphere,13 and atmospheres composed of pure He, C, N, or O; these are illustrated in Fig. 2. To identify promising models, the mass and radius of the atmosphere models were fixed ...
Photometric Mass-to-Light Ratio In addition to a population`s total
... Another useful quantity to know is the rate of mass loss from stars as a function of time. As before, the key to calculating this is to realize that almost all the mass lost from stars comes during the post main-sequence phase of evolution. Thus, the rate at which a population of stars loses mass is ...
... Another useful quantity to know is the rate of mass loss from stars as a function of time. As before, the key to calculating this is to realize that almost all the mass lost from stars comes during the post main-sequence phase of evolution. Thus, the rate at which a population of stars loses mass is ...
Lecture Nine (Powerpoint format) - Flash
... In these cases, the binary period, orbital separation, and masses can all be determined directly. ...
... In these cases, the binary period, orbital separation, and masses can all be determined directly. ...
DTU_9e_ch13
... The core of a high-mass main-sequence star containing between 8 and 25 solar masses becomes a neutron star. The cores of slightly more massive stars may become quark stars. A neutron star is a very dense stellar corpse consisting of closely packed neutrons in a sphere roughly 20 km in diameter. The ...
... The core of a high-mass main-sequence star containing between 8 and 25 solar masses becomes a neutron star. The cores of slightly more massive stars may become quark stars. A neutron star is a very dense stellar corpse consisting of closely packed neutrons in a sphere roughly 20 km in diameter. The ...
AAS_WFXT_Solar_System_11Jan2010
... study. Most objects have been detected with only a few photons. • There is an important list of solar system objects that have yet to be detected in the x-ray : Mercury, the ice giants Uranus/Neptune, the Main Belt comets,KBOs, and the heliopause. • Large Scale WFXT Imaging will allow for direct, co ...
... study. Most objects have been detected with only a few photons. • There is an important list of solar system objects that have yet to be detected in the x-ray : Mercury, the ice giants Uranus/Neptune, the Main Belt comets,KBOs, and the heliopause. • Large Scale WFXT Imaging will allow for direct, co ...
Cygnus X3 - IceCube Neutrino Observatory
... analysis even for long flares, opening up the possibility of looking from GRB timescales to steady sources. For flat emission, only 10% more signal is needed for discovery than a PS search even when we add two degrees of freedom to the likelihood. ...
... analysis even for long flares, opening up the possibility of looking from GRB timescales to steady sources. For flat emission, only 10% more signal is needed for discovery than a PS search even when we add two degrees of freedom to the likelihood. ...
Frantic Finish - Max-Planck
... imum as conventional Type II supernovae. The problem is: “These objects are all extremely far away. We can often register only the light curves, and the spectra are not conclusive in detail,” says Hans-Thomas Janka. What causes these supernovae? The researchers can only speculate. After an initial e ...
... imum as conventional Type II supernovae. The problem is: “These objects are all extremely far away. We can often register only the light curves, and the spectra are not conclusive in detail,” says Hans-Thomas Janka. What causes these supernovae? The researchers can only speculate. After an initial e ...
The Life Cycle of Stars Stars are a fascinating part of our universe
... (97%) and Helium (3%) gas. Gravity causes the dust and gas to clump together. The number of atoms in the clump increases and the mass of the clump increases. This initial mass determines the mass of the star. As the gravitational attraction in the nebula grows the clump contracts and flattens into a ...
... (97%) and Helium (3%) gas. Gravity causes the dust and gas to clump together. The number of atoms in the clump increases and the mass of the clump increases. This initial mass determines the mass of the star. As the gravitational attraction in the nebula grows the clump contracts and flattens into a ...
The Milky Way - Chandra X
... Today we know that the Milky Way is our home galaxy - a vast rotating spiral of gas, dust, and hundreds of billions of stars. The Sun and its planetary system formed in the outer reaches of the Milky Way about 4.5 billion years ago. In the center of the galaxy is the bar-shaped galactic bulge which ...
... Today we know that the Milky Way is our home galaxy - a vast rotating spiral of gas, dust, and hundreds of billions of stars. The Sun and its planetary system formed in the outer reaches of the Milky Way about 4.5 billion years ago. In the center of the galaxy is the bar-shaped galactic bulge which ...
Death of Stars notes
... • A core with remaining mass of 1.4 to 3 M, composed of tightly packed neutrons. • These tiny stars are much smaller than planet Earth -- in fact, they are about the diameter of a large city (~20 km). • One cubic centimeter (like a sugar cube) of a neutron star, would have a mass of about 1011 kg! ...
... • A core with remaining mass of 1.4 to 3 M, composed of tightly packed neutrons. • These tiny stars are much smaller than planet Earth -- in fact, they are about the diameter of a large city (~20 km). • One cubic centimeter (like a sugar cube) of a neutron star, would have a mass of about 1011 kg! ...
Circumstellar interaction in supernovae
... Interaction of the ejected material from the supernovae with their surrounding medium and study them in multiwavebands. ...
... Interaction of the ejected material from the supernovae with their surrounding medium and study them in multiwavebands. ...
Which Stars Form Black Holes and Neutron Stars?
... of these has their own strengths and complications. In principle, if one has identified a supernova associated with a known compact object, it should be possible to infer the mass of the star that exploded from the masses and abundances of metals in the remnant. The Crab nebula is best modeled as de ...
... of these has their own strengths and complications. In principle, if one has identified a supernova associated with a known compact object, it should be possible to infer the mass of the star that exploded from the masses and abundances of metals in the remnant. The Crab nebula is best modeled as de ...
Star Formation Triggers More Star Formation
... decreases. D. Temperature decreases and density increases. ...
... decreases. D. Temperature decreases and density increases. ...
First firm spectral classification of an early-B PMS star
... Evidence of accretion must come from the detection of circumstellar disks and bipolar jets, as observed around forming low-mass stars (e.g., Appenzeller & Mundt 1989). Disks and outflows around massive YSO candidates are being reported (Chini et al. 2004; Kraus et al. 2010; Chapter 3) but the physic ...
... Evidence of accretion must come from the detection of circumstellar disks and bipolar jets, as observed around forming low-mass stars (e.g., Appenzeller & Mundt 1989). Disks and outflows around massive YSO candidates are being reported (Chini et al. 2004; Kraus et al. 2010; Chapter 3) but the physic ...
ANTARES - National Optical Astronomy Observatory
... if there is more than one possible association at the location of the alert, produces replicas that associate the alert with all of the potential AstroObjects at that position. Often, these associations are unrelated, as in the case of a foreground star and a distant galaxy where the alignment is co ...
... if there is more than one possible association at the location of the alert, produces replicas that associate the alert with all of the potential AstroObjects at that position. Often, these associations are unrelated, as in the case of a foreground star and a distant galaxy where the alignment is co ...
Physics@Brock - Brock University
... 42. In order to detect a black hole the astronomers look for (a) a spot into which stars and their planets fall. (b) a very intense source of infrared radiation. (c) a binary system where a companion star is not visible but it has a mass greater than 3 solar mass and is an intense X-ray source. (d) ...
... 42. In order to detect a black hole the astronomers look for (a) a spot into which stars and their planets fall. (b) a very intense source of infrared radiation. (c) a binary system where a companion star is not visible but it has a mass greater than 3 solar mass and is an intense X-ray source. (d) ...
Population synthesis view of gravitational waves - Astro-PF
... Simulation to rates: normalisation Galactic supernova rate, Galactic blue luminosity + blue luminosity density in the local Universe: ...
... Simulation to rates: normalisation Galactic supernova rate, Galactic blue luminosity + blue luminosity density in the local Universe: ...
White dwarfs that crossed the Chandrasekhar limit
... a strange wobbling orbit of Sirius and predicted that this was due to an invisible companion, circling along with it around their common centre of mass. Based on these observations, he calculated the period to be around 50 years and mass almost as much as the Sun (0.98 M). This invisible companion ...
... a strange wobbling orbit of Sirius and predicted that this was due to an invisible companion, circling along with it around their common centre of mass. Based on these observations, he calculated the period to be around 50 years and mass almost as much as the Sun (0.98 M). This invisible companion ...
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.