... A: Because they have an event horizon . ... X-ray astronomers using the space-based Chandra Observatory now believe they have direct for event horizons - therefore black holes - in binary star systems which can be detected in x-ray light. ... But if it is indeed a black hole with a defining event horizon, then the x-ray hot material approaches the speed of light as it swirls past the surface of no return and is lost from view. ... Publications with keywords: black hole - x-ray binary - neutron star ...

... 2001 January 19 . Black Holes Are Black . ... A: Because they have an event horizon . ... X-ray astronomers using the space-based Chandra Observatory now believe they have direct evidence for event horizons - therefore black holes - in binary star systems which can be detected in x-ray light. ... But if it is indeed a black hole with a defining event horizon, then the x-ray hot material approaches the speed of light as it swirls past the surface of no return and is lost from view. ... About APOD | ...

Next: Binary Radiopulsars with Black Up: Black Holes in Binaries Previous: Black Holes in Binaries . Two different types of stellar BH formation exist: (1) direct core collapse   of a massive star and (2) AIC of a NS. A BH of the first type presumably will have a mass comparable to that of the collapsing star and can be born both from a single star and in a binary system. ... Next: Binary Radiopulsars with Black Up: Black Holes in Binaries Previous: Black Holes in Binaries Mike E. Prokhorov . ...

... Abubekerov M.K., Lipunov V.M. "The Lower Temperature Limits Of Accretors" Astronomy Reports, 2003, Vol. 47, Issue 8, pp.679-684. ... Abubekerov M.K., Antokhina E.A., Cherepashchuk A.M. "The Masses of X-ray Pulsars in Binary systems with OB Supergiants" Astronomy Reports, 2004, Vol. ... Abubekerov M.K., Antokhina E.A., Cherepashchuk A.M., Shimanskii V.V. "The Mass of the Compact Object in the Low-Mass X-ray Binary 2S 0921-630" Astronomy Reports Astronomy Reports, 2006, Vol.50, Issue 7, pp.544-552. ...

ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... Information & tools for observers . ... Australia Telescope Online Archive (ATOA) . ... ATCA | ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... The Australia Telescope National Facility Colloquium . ...

home education > resources . ... Resources . ... Astronomy Education Bibliography . ... Black Holes: An Introductory Resource List . ... http://hubblesite.org/explore_astronomy/black_holes/home.html . ... The Universe in the Classroom (The ASP's Newsletter on Teaching Astronomy) Issue on Black Holes by John Percy: . ... For a set of black hole information guides and demonstration activities from the ASP's and JPL's Night Sky Network, click on the link below and check the box on black holes: . ...

... 1) A Multiwavelength Study of Tadpole Galaxies in the Hubble Ultra Deep Field, Straughn, A., et al. (including S. Ravindranath), 2015, ApJ, 814, 97. 2) The Rate of Core Collapse Supernovae to Redshift 2.5 from CANDELS and CLASH Supernova Surveys, Strolger, L., et al. (including S. Ravindranath), 2015, ApJ, 813, 93. ... 18) "Resolved Galaxies in the Hubble Ultra Deep Field: Star Formation in Disks at High Redshift", Elmegreen, D.M., Elmegreen, B.G., Ravindranath, S., Coe, D.A., 2007, ApJ, 658, 763. ...

... SS433 is a close binary system, one star is a supergiant, a second one is a black hole. ... Even a black hole cannot accept such an enormous mass flux, a supercritical accretion disk appears, all the excess gas glows up to several tens of thousands degrees and is ejected off the disk with enormous velocities. ... SAO researchers have found an evidence of the supercritical accretion onto a black hole in SS433, which follows from a brightness variability of the SS433 disk. ...

... The event horizon is the boundary of a black hole) . ... When the supermassive star implodes (collapses under it?s own gravity) a black hole is formed. Many black holes have been found in the centres of galaxies. ... It was thought that black holes don?t give out any energy at all (except when engulfing stars). ... It is thought that as the stars pass near to the centre, they are pulled in by the black hole and forced to remain orbiting around the black hole. ...

... Our Sun is part of a huge wheel-shaped collection of stars. ... Astronomers have long suspected it was a very massive black hole, and that every galaxy had such a central mass, created early in the history of the universe. ... However, unless that object happens to be headed directly at the black hole (a relatively small target) it will just swing around and fly away again, like a comet making a pass at the Sun. The velocity acquired in falling towards the black hole also helps it escape. ...

... We have measured this "redshift" for the pink black holes, and allowed for it in our calculations. ... We see this effect in the emission from gas around these pink black holes, but it is far too small an effect to account for the pinkness. Thus the swirling motions of gas around or into the black holes cannot produc the colour. ... At first we thought that these things were normal blue black holes hidden behind clouds of interstellar dust, that absorbed the blue light and made them appear pink. ...

Smithsonian Astrophysical Observatory | Center for Astrophysics | Smithsonian Institution | XRB SED Home | . RXTE Light Curves (and tables of SED data times where available): . J0422+32 . V616 Mon (A0620-00) . GRS1009-45 . J1118+480 . 4U1124-684 . J1543-475 . GRO J1655-40 . GX339-4 . GX1915+105 . SEDs: . V616 Mon (A0620-00) . XTE J1118+480 . GRO J1655-40 . GRS1915+105 . GX339-4 .

Blackholes2 Forum Message . ... Holostars: Black Holes Without Event Horizons . ... Its name derives from the fact tht information is preserved in such a black hole, and must be a contraction of hologram and star. ... The exterior metrics and fields of the charged holostar are equal to the Reissner-Nordstroem black hole solution. ... www.astronomy.net . ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

... Science . ... Science Users Information > Science and Technical Meetings > Conferences 1999 > bh99 . ... Observing with ESO Telescopes . ... Data Handling and Products . ... ESO Data . ... Science in Garching . ... ESO Headquarters, Garching bei MУМnchen, Germany . The aim of this workshop is to bring together astrophysicists working on the rather separate fields of stellar-mass and supermassive black holes, with emphasis on the formation, population, physics, and environments of black holes. ...

... V4641 Sgr is known as a detached binary containing a 9 Msol. black hole and an A0 type companion. ... Spectra of V4641 Sgr were taken by us using SAO 1-m telescope between May 23.972 and 24.002 UT (the orbital phase of 0.35), wavelength range 3900-7500A, resolution 8A, S/N~30-40. ... These observations show essential light excess over the quiet light level seen only in the orbital phases between -0.25 and +0.25 with the maximum value of 0.15 mag in the V band at the black hole inferior conjunction. ...

... Over the first 4 years, its X-ray telescopes eROSITA and ART-XC will survey the whole sky with a record sensitivity in the 0.5-10 keV energy band. ... The goal of the second international Spectrum-RG conference is to discuss the different scientific topics addressed by the mission, synergies with surveys at other wavelengths, and requirements to follow-up observations.Contributed talks and poster presentations are invited on the topics related to the SRG science goals. ... Active galactic nuclei . ...

... NASA's Hubble Space Telescope has provided a never-before-seen view of a warped disk flooded with a torrent of ultraviolet light from hot gas trapped around a suspected massive black hole. ... This composite image of the core of the galaxy was constructed by combining a visible light image taken with Hubble's Wide Field Planetary Camera 2 (WFPC2), with a separate image taken in ultraviolet light with the Faint Object Camera (FOC). ... The inset box shows Hubble Space Telescope's field of view. ...

... Seminar archive . ... The structure of the X-ray sources in the hard spectral state of accreting black-hole binaries has been a subject of intense debate. The paradigm dominant for many years postulated that the accretion disc in the hard state is truncated at some radius >> the innermost stable orbit (ISCO) whereas the disc reaches the ISCO in the soft state. ... On the other hand, there have been numerous claims in recent years that the disc extends to the ISCO in the hard state. ...

... Bad Astronomy . Misconceptions . ... Bad Astronomy : If the Sun collapses into a black hole, the Earth and all the other planets will get sucked in. Good astronomy : If the Sun were to collapse into a black hole, we would feel no difference in the gravity as measured at the Earth. ... The same applies if the Sun were to collapse into a black hole. ... Therefore, the gravity of the Sun felt at the Earth would remain the same. ... So it is with the black hole Sun. ... 2008 Phil Plait. ...

... Elena Seifina and Lev Titarchuk "On the nature of the compact object in SS433: observational evidence of X-ray photon index saturation" 2010, Astrophysical. ... A.M. Cherepashchuk, R.A. Sunyaev, E.V. Seifina, E.A. Antokhina, D.I. Kosenko, S.V. Molkov, N.I. Shakura, K.A. Postnov, A.N. Timokhin, I.E. Panchenko "INTEGRAL Observations of SS433: Analysis of Precessional and Orbital X-ray Periodicities" 2007, 6th INTEGRAL Workshop, Eds. S. Grebenev, R.A. Sunyaev, p.411 (astro-ph/0610235) . ...