L43 THE STARFISH TWINS: TWO YOUNG
... He 2-47 and a = 18 05 25.725, d = 2287229040. 21 for M1-37. The two rings in He 2-47 appear to be point-symmetric about a common geometric center, which is offset from the central star by 00. 21 (cross, Fig. 1b). Similarly, the bright curved edges of lobes N1 and S4 in M1-37 (labeled a and a9 in Fig ...
... He 2-47 and a = 18 05 25.725, d = 2287229040. 21 for M1-37. The two rings in He 2-47 appear to be point-symmetric about a common geometric center, which is offset from the central star by 00. 21 (cross, Fig. 1b). Similarly, the bright curved edges of lobes N1 and S4 in M1-37 (labeled a and a9 in Fig ...
Constraining tidal dissipation in F-type main
... ages of the systems, which implies that the synchronous final state has possibly already been reached. Other systems, e.g., HD15082/WASP-33, have a star so massive that a Qs too large to be measurable is expected, or show a remarkable misalignment between the stellar spin and the orbital angular mo ...
... ages of the systems, which implies that the synchronous final state has possibly already been reached. Other systems, e.g., HD15082/WASP-33, have a star so massive that a Qs too large to be measurable is expected, or show a remarkable misalignment between the stellar spin and the orbital angular mo ...
PDF file
... Galaxy were born in OB associations. The most recent work further suggests that a significant fraction of the stellar population may have their origin in the more spread out regions of OB associations, instead of all being born in dense clusters. Ground-based and space-based (Spitzer Space Telescope ...
... Galaxy were born in OB associations. The most recent work further suggests that a significant fraction of the stellar population may have their origin in the more spread out regions of OB associations, instead of all being born in dense clusters. Ground-based and space-based (Spitzer Space Telescope ...
Massive Star Formation in the Galactic Center
... in the “Central Molecular Zone” (CMZ), noting that the molecular clouds in the region are extraordinarily dense (n > 104 cm−3 ) and warm (T ∼ 70 K) with respect to those found in the disk of the Galaxy. Stark et al. (1989) argue that the density and internal velocities of clouds in the GC are a dire ...
... in the “Central Molecular Zone” (CMZ), noting that the molecular clouds in the region are extraordinarily dense (n > 104 cm−3 ) and warm (T ∼ 70 K) with respect to those found in the disk of the Galaxy. Stark et al. (1989) argue that the density and internal velocities of clouds in the GC are a dire ...
Museum Educator`s Guide
... Introducing the Activity Challenge visitors to put in order photographs of people in various stages of life. Encourage them to notice details of the images and justify their reasoning by identifying features and patterns in each “stage” (e.g. graying hair, smaller size during infancy). If you wish, ...
... Introducing the Activity Challenge visitors to put in order photographs of people in various stages of life. Encourage them to notice details of the images and justify their reasoning by identifying features and patterns in each “stage” (e.g. graying hair, smaller size during infancy). If you wish, ...
1. introduction 2. disk surface stability: outer disk - CRyA-UNAM
... region of the disk where temperature and height are coupled. But for steady disks, larger M0 implies larger viscous dissipation Ñux and disk optical depth, and the assumption of vertical isothermality breaks down, at least for the inner and optically thick regions of the disk. In this case, equation ...
... region of the disk where temperature and height are coupled. But for steady disks, larger M0 implies larger viscous dissipation Ñux and disk optical depth, and the assumption of vertical isothermality breaks down, at least for the inner and optically thick regions of the disk. In this case, equation ...
The peculiar dipping events in the disc-bearing young
... deepest event observed in the EPIC 204278916 light curve corresponds to τ ≈ 65 per cent, thus implying that at least some of the clumps are a sizable fraction of the parent star. This is however a strong lower limit since a completely opaque spherical clump would produce a symmetrical dip, which we ...
... deepest event observed in the EPIC 204278916 light curve corresponds to τ ≈ 65 per cent, thus implying that at least some of the clumps are a sizable fraction of the parent star. This is however a strong lower limit since a completely opaque spherical clump would produce a symmetrical dip, which we ...
ALMA OBSERVATIONS OF THE DEBRIS DISK AROUND THE YOUNG SOLAR... Ricci ,
... presents the ALMA map of the λ1.25 mm continuum emission from HD 107146 obtained with natural weighting using a Briggs robust parameter of 2. This weighting scheme gives a synthesized beam of 1. 15 × 0. 84, corresponding to a spatial resolution of about 32 × 23 AU at the distance of HD 107146. F ...
... presents the ALMA map of the λ1.25 mm continuum emission from HD 107146 obtained with natural weighting using a Briggs robust parameter of 2. This weighting scheme gives a synthesized beam of 1. 15 × 0. 84, corresponding to a spatial resolution of about 32 × 23 AU at the distance of HD 107146. F ...
The Kerr-Metric: describing Rotating Black Holes
... for very dense and massive objects to have an escape velocity larger than the speed of light. Not even light could escape from such an object: it would appear black. In 1915 Einstein published his famous theory of general relativity. This new theory predicted the possibility of such dark objects (ca ...
... for very dense and massive objects to have an escape velocity larger than the speed of light. Not even light could escape from such an object: it would appear black. In 1915 Einstein published his famous theory of general relativity. This new theory predicted the possibility of such dark objects (ca ...
Luminosity, Flux and Magnitudes Outline
... by the microscopic motions of particles. There is a continuum of energy levels associated with this motion. If the object is in thermal equilibrium then it can be characterized by a single quantity, it’s temperature. An object in thermal equilibrium emits energy at all wavelengths. ...
... by the microscopic motions of particles. There is a continuum of energy levels associated with this motion. If the object is in thermal equilibrium then it can be characterized by a single quantity, it’s temperature. An object in thermal equilibrium emits energy at all wavelengths. ...
Document
... Summary of Solar Flares • Magnetic loops become entangled by motions of the footprints, storing magnetic energy • This energy is released through rapid magnetic reconnection that accelerates particles. • Flares emit in all wavelength regimes. • The general theory is well-established, but the detail ...
... Summary of Solar Flares • Magnetic loops become entangled by motions of the footprints, storing magnetic energy • This energy is released through rapid magnetic reconnection that accelerates particles. • Flares emit in all wavelength regimes. • The general theory is well-established, but the detail ...
H.E.S.S. observations of the binary system PSR B1259
... suggests a mass of the star M∗ ≈ 30 M and an orbital inclination angle iorb ≈ 25◦ for the smallest neutron star mass of 1.4 M . The optical observations also suggest that the system is located at the same distance as the star association Cen OB1 at d = (2.3 ± 0.4) kpc (Negueruela et al. 2011). The ...
... suggests a mass of the star M∗ ≈ 30 M and an orbital inclination angle iorb ≈ 25◦ for the smallest neutron star mass of 1.4 M . The optical observations also suggest that the system is located at the same distance as the star association Cen OB1 at d = (2.3 ± 0.4) kpc (Negueruela et al. 2011). The ...
Models of the Structure and Evolution of Protoplanetary Disks
... status of the field. We focus on the regions of the disk beyond the dust sublimation radius, since the very inner regions are discussed in the chapter by Najita et al.. To limit our scope further, we restrict our review to models primarily aimed at a comparison with observations. We ...
... status of the field. We focus on the regions of the disk beyond the dust sublimation radius, since the very inner regions are discussed in the chapter by Najita et al.. To limit our scope further, we restrict our review to models primarily aimed at a comparison with observations. We ...
Evolution of Circumstellar Disks Around Normal Stars
... 2005) have completed a volume–limited survey of nearby sun–like stars with probable ages between 1–3 Gyr old. Overall the Spitzer statistics suggest a cold debris disk frequency of 10–20 % surrounding sun–like stars with a weak dependence on stellar age (Fig. 1). It should be noted that our own sola ...
... 2005) have completed a volume–limited survey of nearby sun–like stars with probable ages between 1–3 Gyr old. Overall the Spitzer statistics suggest a cold debris disk frequency of 10–20 % surrounding sun–like stars with a weak dependence on stellar age (Fig. 1). It should be noted that our own sola ...
Does feedback help or hinder star formation? The effect of
... luminosity was then trapped in the dense cloud. The result was a rise in temperature that suppressed fragmentation to form more massive stars. The differences do not stop with the global cloud properties. Clouds are not uniform gas distributions that form stars only within a dense central region. Ra ...
... luminosity was then trapped in the dense cloud. The result was a rise in temperature that suppressed fragmentation to form more massive stars. The differences do not stop with the global cloud properties. Clouds are not uniform gas distributions that form stars only within a dense central region. Ra ...
Transparencies - Rencontres de Moriond
... • Astrometry : 0".16 (Tycho sources) • 0.5-7 keV : diffuse emission + 119 point sources • One source coincident with SgrA* within 0".27 ...
... • Astrometry : 0".16 (Tycho sources) • 0.5-7 keV : diffuse emission + 119 point sources • One source coincident with SgrA* within 0".27 ...
epsilon eridani`s planetary debris disk: structure and dynamics
... subtracted to enable the study of the circumstellar emission. The spectral leak is field-dependent, and, therefore, can only be properly subtracted using a reference star that was observed with the same dither parameters as the science target. Prelaunch observation planning did not anticipate this r ...
... subtracted to enable the study of the circumstellar emission. The spectral leak is field-dependent, and, therefore, can only be properly subtracted using a reference star that was observed with the same dither parameters as the science target. Prelaunch observation planning did not anticipate this r ...
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.