Orbital Period Modulation in Chromospherically
... However we should bear in mind that the orbital period modulation should not be strictly periodic. The examples of the application are given in Table 1. The model proposed by Applegate takes the orbital period modulations in the active close binaries as a signature of stellar magnetic activity. The ...
... However we should bear in mind that the orbital period modulation should not be strictly periodic. The examples of the application are given in Table 1. The model proposed by Applegate takes the orbital period modulations in the active close binaries as a signature of stellar magnetic activity. The ...
GRB 021004: A Possible Shell Nebula around a Wolf
... One is thus led to consider scenarios where the absorbers are closer to the GRB progenitor system (i.e., associated). Hot, massive stars generally have expanding material characterized by velocities of up to 3,000 km s−1 , which originates through the scattering of stellar radiation in the stellar w ...
... One is thus led to consider scenarios where the absorbers are closer to the GRB progenitor system (i.e., associated). Hot, massive stars generally have expanding material characterized by velocities of up to 3,000 km s−1 , which originates through the scattering of stellar radiation in the stellar w ...
Effects of color superconductivity on the nucleation of
... higher densities and makes the conversion to quark stars less likely. For the QMC model, the metastability region is very narrow. The EoS is very sofy and therefore the onset of hyperons occurs at quite high densities, which gives rise to large critical masses. The converstion to a quark star will o ...
... higher densities and makes the conversion to quark stars less likely. For the QMC model, the metastability region is very narrow. The EoS is very sofy and therefore the onset of hyperons occurs at quite high densities, which gives rise to large critical masses. The converstion to a quark star will o ...
transparencies - Rencontres de Moriond
... Principle of the measurements with GRAVITY Reference source for infrared ...
... Principle of the measurements with GRAVITY Reference source for infrared ...
WASP-35b, WASP-48b, AND HAT-P-30b/WASP
... Most of the known transiting exoplanets orbit very close to their host star, which produces strong tidal forces between them. The tidal interactions may result in orbital circularization, synchronization, and decay (Pont 2009). An apparent relationship between period and eccentricity of non-transiti ...
... Most of the known transiting exoplanets orbit very close to their host star, which produces strong tidal forces between them. The tidal interactions may result in orbital circularization, synchronization, and decay (Pont 2009). An apparent relationship between period and eccentricity of non-transiti ...
L143 HALTING PLANET MIGRATION BY PHOTOEVAPORATION
... accretion and photoevaporation, operating in concert within the disk. In this Letter, we consider photoevaporation by the central source and viscous accretion. ...
... accretion and photoevaporation, operating in concert within the disk. In this Letter, we consider photoevaporation by the central source and viscous accretion. ...
Neutron Stars PowerPoint
... • Deduced from cyclical Doppler shift every 1.7 days • Pulsing period of ~ 1.24 seconds ...
... • Deduced from cyclical Doppler shift every 1.7 days • Pulsing period of ~ 1.24 seconds ...
Determining the Nature of a Double Star: The Law of Conservation
... 2.5 km s-1. From the stellar masses for the components (3.8 and 1.0 M), the projected separation (957 AU) and the expected semi-major axis (1,206 AU), I calculated a maximum orbital velocity of 2.34 km s-1 using equation (6). Using equation (15b), I calculated an escape velocity of 2.98 km s-1. It ...
... 2.5 km s-1. From the stellar masses for the components (3.8 and 1.0 M), the projected separation (957 AU) and the expected semi-major axis (1,206 AU), I calculated a maximum orbital velocity of 2.34 km s-1 using equation (6). Using equation (15b), I calculated an escape velocity of 2.98 km s-1. It ...
PowerPoint
... the right answer is, and more importantly, why it is right. – You will need to understand and be able to use any equations that have been introduced in class. Calculations using these equations will be kept simple--it is possible to do the exam without a calculator, but you can bring one if you wish ...
... the right answer is, and more importantly, why it is right. – You will need to understand and be able to use any equations that have been introduced in class. Calculations using these equations will be kept simple--it is possible to do the exam without a calculator, but you can bring one if you wish ...
Discovery of an unusual bright eclipsing binary with the longest
... Fig. 5. Spectral energy distributions of the “hot component” (open circles) and a standard B6V star (thick line). Fig. 3. MASTER OT J095310.04+335352.8 spectrum obtained after eclipse on 2015-03-19. One can see the red part of an after eclipse spectrum. We note that Hα and NaI doublet are in absorpt ...
... Fig. 5. Spectral energy distributions of the “hot component” (open circles) and a standard B6V star (thick line). Fig. 3. MASTER OT J095310.04+335352.8 spectrum obtained after eclipse on 2015-03-19. One can see the red part of an after eclipse spectrum. We note that Hα and NaI doublet are in absorpt ...
Soft X-Ray Polarimetry
... of soft X-rays. Because of the lack of observations, there has been very little theoretical work to predict polarization fractions or position angles but there has been some recent progress with the prospect of a small explorer, the Gravitation and Extreme Magnetism SMEX (GEMS) 34 . GEMS will carry ...
... of soft X-rays. Because of the lack of observations, there has been very little theoretical work to predict polarization fractions or position angles but there has been some recent progress with the prospect of a small explorer, the Gravitation and Extreme Magnetism SMEX (GEMS) 34 . GEMS will carry ...
Neutron Stars PowerPoint
... • Deduced from cyclical Doppler shift every 1.7 days • Pulsing period of ~ 1.24 seconds ...
... • Deduced from cyclical Doppler shift every 1.7 days • Pulsing period of ~ 1.24 seconds ...
Credit: X-ray: NASA/CXC/UMass/D. Wang et al.; Optical: Caltech/SSC/S.Stolovy
... flares, few×1034 erg s-1 ...
... flares, few×1034 erg s-1 ...
CHANDRA on ,
... We present an analysis of a pointed 141 ks Chandra high-resolution transmission gratings observation of the Be X-ray emitting star HD110432, a prominent member of the γ Cas analogs. This observation represents the first high-resolution spectrum taken for this source as well as the longest uninterrup ...
... We present an analysis of a pointed 141 ks Chandra high-resolution transmission gratings observation of the Be X-ray emitting star HD110432, a prominent member of the γ Cas analogs. This observation represents the first high-resolution spectrum taken for this source as well as the longest uninterrup ...
presentation source
... with periods ranging from a few years to a few hours. Recall that this light variation places an upper limit on the size of the quasar’s energy source. If they are as distant as Hubble’s Law indicates then some mechanism must be producing energies greater than 100s of galaxies in a region about the ...
... with periods ranging from a few years to a few hours. Recall that this light variation places an upper limit on the size of the quasar’s energy source. If they are as distant as Hubble’s Law indicates then some mechanism must be producing energies greater than 100s of galaxies in a region about the ...
Rotating Disk-Jet System of the NGC 1333 IRAS 4A2 Protostar
... Astrophysical jets play important roles in many interesting astronomical phenomena, such as star formation and active galactic nuclei. The jets are thought to be driven by rotating disks through magneto-centrifugal processes. However, quantitative understanding of the jet-driving mechanism has been ...
... Astrophysical jets play important roles in many interesting astronomical phenomena, such as star formation and active galactic nuclei. The jets are thought to be driven by rotating disks through magneto-centrifugal processes. However, quantitative understanding of the jet-driving mechanism has been ...
ph600-12 - University of Kent
... We present an evolutionary picture of a forming star. We assume a singular isothermal sphere as the initial state of the core that undergoes collapse, as described by Shu. We include the evolution of a first hydrostatic core at early times and allow a disk to grow, as predicted by Adams & Shu. We us ...
... We present an evolutionary picture of a forming star. We assume a singular isothermal sphere as the initial state of the core that undergoes collapse, as described by Shu. We include the evolution of a first hydrostatic core at early times and allow a disk to grow, as predicted by Adams & Shu. We us ...
Science Argumentative Writing Prompt Problem: Scientists have
... nebula into a thin disk of gas and dust. A proto-star (proto = early) forms at the core, surrounded by a rotating proto-planetary disk. Through a process called accretion (i.e., sticky collision) dust particles in the disk steadily accumulate mass to form ever-larger bodies. Local concentrations of ...
... nebula into a thin disk of gas and dust. A proto-star (proto = early) forms at the core, surrounded by a rotating proto-planetary disk. Through a process called accretion (i.e., sticky collision) dust particles in the disk steadily accumulate mass to form ever-larger bodies. Local concentrations of ...
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.