1: Properties of Pulsars
... dwarfs. Only neutron stars were left as a possible explanation. Periods for radial oscillations of neutron stars were predicted to be larger than 1 second and were hence incompatible with the periods of the first discovered pulsars. Finally, another property of pulsars, also most easily observed in ...
... dwarfs. Only neutron stars were left as a possible explanation. Periods for radial oscillations of neutron stars were predicted to be larger than 1 second and were hence incompatible with the periods of the first discovered pulsars. Finally, another property of pulsars, also most easily observed in ...
CH14.AST1001.S15.EDS
... • Nothing can escape from within the event horizon because nothing can go faster than light. • No escape means there is no more contact with something that falls in. It increases the hole's mass, changes its spin or charge, but otherwise loses its identity. ...
... • Nothing can escape from within the event horizon because nothing can go faster than light. • No escape means there is no more contact with something that falls in. It increases the hole's mass, changes its spin or charge, but otherwise loses its identity. ...
X-ray polarimetry in astrophysics
... A PWN was first observed in Crab SNR, and then detected in many others X-ray sources X-rays emitting particles have a short lifetime for synchrotron losses, and they are present only in the vicinity of the TS. Not imaging X-ray polarimetry from the Crab Nebula shows a polarization of 19 % (2.6 keV, ...
... A PWN was first observed in Crab SNR, and then detected in many others X-ray sources X-rays emitting particles have a short lifetime for synchrotron losses, and they are present only in the vicinity of the TS. Not imaging X-ray polarimetry from the Crab Nebula shows a polarization of 19 % (2.6 keV, ...
A seismic and gravitationally-bound double star observed by Kepler
... pairs of binary stars that were observed by Kepler. The pair 16 Cyg A and 16 Cyg B is a pair for which solar-like p modes were observed (Metcalfe et al. 2012). Unfortunately, although these two stars are gravitationally bound, the orbital period is estimated to be longer than 30,000 years (Hauser & ...
... pairs of binary stars that were observed by Kepler. The pair 16 Cyg A and 16 Cyg B is a pair for which solar-like p modes were observed (Metcalfe et al. 2012). Unfortunately, although these two stars are gravitationally bound, the orbital period is estimated to be longer than 30,000 years (Hauser & ...
Resultados del Concurso 2008A para Observaciones en
... Resumen: It is currently problematic to measure ages of Galactic globular cluters (GCs) over the full range of observed metallicities using near-infrared photometry alone, because models cannot reliably reproduce the observed morphology in near-IR color-magnitude diagrams (CMDs). While a handful of ...
... Resumen: It is currently problematic to measure ages of Galactic globular cluters (GCs) over the full range of observed metallicities using near-infrared photometry alone, because models cannot reliably reproduce the observed morphology in near-IR color-magnitude diagrams (CMDs). While a handful of ...
Article PDF - IOPscience
... Neptune and other hypothetical massive planetary embryos or of its temporary capture in a resonance with one of the other planets, although these scenarios have never been quantitatively simulated. In this section we investigate the effects that an eccentric Neptune would have on the formation of th ...
... Neptune and other hypothetical massive planetary embryos or of its temporary capture in a resonance with one of the other planets, although these scenarios have never been quantitatively simulated. In this section we investigate the effects that an eccentric Neptune would have on the formation of th ...
cranmer_nessc_oct2008
... • Rivinius et al. (1998, 2001) found correlations between emission-line “outbursts” and constructive interference (“beating”) between NRP periods. ...
... • Rivinius et al. (1998, 2001) found correlations between emission-line “outbursts” and constructive interference (“beating”) between NRP periods. ...
Discovery of Eclipsing Binary with the Longest Known Period
... spectra is that the after eclipse the observed SED is similar to standard M1 SED even in the blue region (Fig. 7, Fig.8). Let’s assume that the red giant has no sufficient intrinsic variability, and neglect the limbdarkening effect. We subdivided the after eclipse spectrum into 270 for continuum flu ...
... spectra is that the after eclipse the observed SED is similar to standard M1 SED even in the blue region (Fig. 7, Fig.8). Let’s assume that the red giant has no sufficient intrinsic variability, and neglect the limbdarkening effect. We subdivided the after eclipse spectrum into 270 for continuum flu ...
Theoretical Models of the Structure of Protoplanetary Disks Les
... parcel wants to slowly spiral inward to the star (i.e. accretion), then it must evidently lower its specific angular momentum l, because r decreases. Without any torque on this fluid element, it will thus not accrete and instead rotate forever in a circular orbit around the star. Viscosity can, howe ...
... parcel wants to slowly spiral inward to the star (i.e. accretion), then it must evidently lower its specific angular momentum l, because r decreases. Without any torque on this fluid element, it will thus not accrete and instead rotate forever in a circular orbit around the star. Viscosity can, howe ...
A) Polaris B) Betelgeuse C) Procyon B D) Sirius 1. Which star has a
... the same luminosity as the star Aldebaran approximately the same temperature as the Rigel. Algol is best classified as a A) main sequence star B) red giant star C) white dwarf star D) red dwarf star 60. Two stars of the same color are plotted on an H-R diagram. Star A is more luminous than star B. W ...
... the same luminosity as the star Aldebaran approximately the same temperature as the Rigel. Algol is best classified as a A) main sequence star B) red giant star C) white dwarf star D) red dwarf star 60. Two stars of the same color are plotted on an H-R diagram. Star A is more luminous than star B. W ...
Star Formation in the Galaxy, An Observational Overview
... are clearly gravitationally bound if not highly unstable entities. Measurements of molecular linewidths indicate cloud velocity dispersions of 2-3 km s−1 . The velocity fields of these objects are highly supersonic given the cloud sound speeds, cs ∼ 0.2 km s−1 . These supersonic motions for the most ...
... are clearly gravitationally bound if not highly unstable entities. Measurements of molecular linewidths indicate cloud velocity dispersions of 2-3 km s−1 . The velocity fields of these objects are highly supersonic given the cloud sound speeds, cs ∼ 0.2 km s−1 . These supersonic motions for the most ...
The Stellar Initial Mass Function and Beyond
... addition that the mass spectrum of these clumps resembles not only the standard stellar IMF described above, but also the IMF of the young stars in the ρ Oph cloud itself. It may be premature to claim that there is quantitative agreement between the clump mass spectrum and the stellar IMF, since a s ...
... addition that the mass spectrum of these clumps resembles not only the standard stellar IMF described above, but also the IMF of the young stars in the ρ Oph cloud itself. It may be premature to claim that there is quantitative agreement between the clump mass spectrum and the stellar IMF, since a s ...
Chapter 2 Mass Transfer in Binary Systems
... Example: Supersoft X-ray sources Supersoft X-ray sources were first discovered with Einstein Observatory and about four dozen new with the ROSAT satellite. ...
... Example: Supersoft X-ray sources Supersoft X-ray sources were first discovered with Einstein Observatory and about four dozen new with the ROSAT satellite. ...
L103 A NEW MILKY WAY DWARF SATELLITE IN CANES
... of the Milky Way. Together with the two dwarf irregulars (the Large and Small Magellanic Clouds), these make up all the known satellite galaxies of the Milky Way. The dSphs have such low surface brightness that they have often been found serendipitously. For example, while Sextans (Irwin et al. 1990 ...
... of the Milky Way. Together with the two dwarf irregulars (the Large and Small Magellanic Clouds), these make up all the known satellite galaxies of the Milky Way. The dSphs have such low surface brightness that they have often been found serendipitously. For example, while Sextans (Irwin et al. 1990 ...
Physics of Star Formation: Milky Way and Beyond
... winds, super novae, and multi-band radiation transport and pressure. As our understanding of stellar feedback is tied to interpreting observations, we also present OPIATE, an Optimal Post-processing Iterative Approach to Emissivities, a general purpose, publicly available code and data base for live ...
... winds, super novae, and multi-band radiation transport and pressure. As our understanding of stellar feedback is tied to interpreting observations, we also present OPIATE, an Optimal Post-processing Iterative Approach to Emissivities, a general purpose, publicly available code and data base for live ...
Stellar Evolution
... rotates, its two spiral arms can compress a GMC, which then leads to star formation. ...
... rotates, its two spiral arms can compress a GMC, which then leads to star formation. ...
Student Activity: Using a Mariner`s Astrolabe
... Students could use their astrolabes to collect data observing the change in position of the Moon, Polaris, and other celestial objects in the night sky. Depending on the season you could direct students to observe specific celestial objects, e.g., Jupiter, Betelgeuse, other stars of Orion in the win ...
... Students could use their astrolabes to collect data observing the change in position of the Moon, Polaris, and other celestial objects in the night sky. Depending on the season you could direct students to observe specific celestial objects, e.g., Jupiter, Betelgeuse, other stars of Orion in the win ...
docx - STAO
... Students could use their astrolabes to collect data observing the change in position of the Moon, Polaris, and other celestial objects in the night sky. Depending on the season you could direct students to observe specific celestial objects, e.g., Jupiter, Betelgeuse, other stars of Orion in the win ...
... Students could use their astrolabes to collect data observing the change in position of the Moon, Polaris, and other celestial objects in the night sky. Depending on the season you could direct students to observe specific celestial objects, e.g., Jupiter, Betelgeuse, other stars of Orion in the win ...
Chapter 2 Observing the Electromagnetic Spectrum
... Not all photons emitted by astronomical objects are detected by ground-based telescopes. A major barrier to the photons path is the Earth’s ionosphere and upper atmosphere that absorbs or scatters most incoming radiation except for the optical (wavelengths of 3300-8000Å where 1 Å = 10−10 m), parts ...
... Not all photons emitted by astronomical objects are detected by ground-based telescopes. A major barrier to the photons path is the Earth’s ionosphere and upper atmosphere that absorbs or scatters most incoming radiation except for the optical (wavelengths of 3300-8000Å where 1 Å = 10−10 m), parts ...
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.