... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

... In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole. Studies of the bright light emitted by the swirling gas frequently indicate not only that a black hole is present, but also likely attributes. ... The Milky Way flows through this celestial expanse whose wonders also include the closest star to the sun, Alpha Centauri, and the largest globular star cluster in our galaxy, Omega Centauri. NGC 1579: Trifid of the North . ...

... These Frontier Fields will combine the power of HST with the natural gravitational telescopes of high-magnification clusters of galaxies. ... We are soliciting gravitational lensing maps for the last four Hubble Frontier Fields clusters (MACSJ0717.5+3745, MACSJ1149.5+2223, AbellS1063, and Abell 370) based upon the exceptionally deep HST FF imaging and other new ancillary data. ... For the full set of proposal instructions and requirements, see the FY16 Frontier Fields Lensing Map Call for Proposals....

Today's APOD | ... Editor's choices for the most educational Astronomy Pictures of the Day about black holes: . ... If alone, a black hole would indeed appear quite black, but many black hole candidates are part of binary star systems . So how does a black hole binary system look different from a neutron star binary system ? ... A black hole system so equipped would appear much darker than a similar neutron star system. ... APOD: 2004 February 24 - X-Rays Indicate Star Ripped Up by Black Hole . ...

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

... Ultraluminous X-ray sources (ULXs) are located in external galaxies, their X-ray luminosities (10 39 - 10 41 erg/s) are thousand times greater than those of brightest black holes in the Galaxy. ULXs may be supercritical accretion disks around black holes of stellar masses (~10 Solar masses) like that in SS433, or they may be a hypothetical intermediate-mass black holes (hundreds - thousands Solar masses) with standard accretion disks. ... 2) The ULX progenitors were ejected from the star clusters. ...

... Tonight's Sky . ... Sky this Month . ... Star Atlas . ... stars . ... The Sky This Week: April 1 - 10 . ... Observing springtime deep-sky objects with a large telescope . ... Why do some stars appear to flash a variety of different colors when you look at them through a telescope? ... So, Earthт??s atmosphere will bend some colors from especially bright stars more so than others, which makes the source look like itт??s flashing colors. Get instant access to subscriber content on Astronomy.com! ...

... STScI-PRC99-30 HUBBLE SPIES GIANT STAR CLUSTERS NEAR GALACTIC CENTER Penetrating 25,000 light-years of obscuring dust and myriad stars, NASA’s Hubble Space Telescope has provided the clearest view yet of a pair of the largest young clusters of stars inside our Milky Way galaxy, located less than 100 light-years from the very center of the Galaxy. ... But in the brief time they are around, they shine more brightly than any other star cluster in the Galaxy. ...

... The Sun . Does anyone know how many stars are there in the solar system? Come take a look at the Sun. See that? ... Did you know all the stars you see when you look up are inside our galaxy! ... Did you know that our Sun and solar system were born in a cloud of gas and dust like this. ... We're looking at a place where stars are being born. ... Sharing the Universe is based upon work supported by the Informal Education Division of the National Science Foundation under Grant no DRL-0638873. ...

... Astronomy news . ... NASA's Spitzer Images Out-of-This-World Galaxy . ... It is spiral-shaped like our Milky Way, with long, spindly arms of stars. The "eye" at the center of the galaxy is actually a monstrous black hole surrounded by a ring of stars. In this color-coded infrared view from Spitzer, the area around the invisible black hole is blue and the ring of stars, white. ... The ring around the black hole is bursting with new star formation. ...

... Galileo was one of the first to study our Milky Way with a telescope in 1610 and he discovered that it was composed of a huge number of faint stars. ... Image Credit: NASA Elliptical Galaxy This image from NASA's Hubble Space Telescope shows a good example of an elliptical galaxy at the centre of a galaxy cluster that is over 450 million light-years away in the direction of the constellation Centaurus. ... Then the Andromeda galaxy was first classed as a galaxy outside of our own Milky Way. ...

Astronomy suffers from the `Static Illusion' - because astronomical changes usually occur over intervals much longer than a human lifetime they appear static. This illusion affects our understanding of how astronomical objects work. ... Observations at the 1/10th arcsecond level with HST and near-infrared adaptive optics on ground based telescopes are beginning to create movies of `astronomy in motion'. ... Proto-star HH-30 expanding jet HST.. Young binary, XZ Tau, expanding `bubbles' HST.. ...

... Special Reports Giant space cloud may be powered by black holes 17:57 23 April 2007 NewScientist.com news service David Shiga An enormous cloud of roiling plasma in space may be drawing its energy from black holes, new observations suggest. Such clouds might be sources for the mysterious particles that occasionally crash into Earth's atmosphere at ultra - high speed. ... But higher energy particles in the cloud may be able to escape, he says. ...

... The jets can also be produced in smaller scale by binary stellar systems. ... Some 200 -- 250 X-ray binaries, systems in which a neutron star or black hole is accreting material from a companion star, are known. Approximately 20% of these sources have been detected at radio wavelengths, and in several cases high resolution radio observations have resolved this emission into jet-like structures, sometimes with components moving at relativistic velocities. ... It is variable radio source. ...

... Neutral and Ionised Hydrogen in NGC 4214 V. J. McIntyre1,2 1 2 Physics Department, University of Wollongong, Wollongong, NSW 2522, Australia Astrophysics Department, University of Sydney, NSW 2006, Australia vjm@physics.usyd.edu.au Abstract: It is not clear at present how the diffuse ionised gas (DIG) component in galaxies is ionised. ... How porous the ISM must be depends on the (unknown) location of the ionised emission relative to the disk. ... 1996). ... Local H I surface density is 2в1021 cm-3 ...

... 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. ...

The FR Divide in Radio Galaxies through Environmental Interactions T. Maciel (Astrophysics Group) tm419@cam.ac.uk , P. Alexander (Astrophysics Group) Radio -Loud Galaxies · Galaxies which are dominated by their radio emission (10MHz -100GHz) and show extended morphology: - Jets Active Galactic Nuclei -Lobes powered by (AGN) -Hotspots -Central black hole -Accretion disc -Strong B fields -Dusty torus Chandra X-Ray image of Perseus cluster with VLA ... Right: FRII galaxy 3C175 at 5GHz. ...

Observations over the last decade indicate black-holes likely resided at the heart of most if not all galaxies. The correlation between the masses of these compact nuclear sources and their host galaxy is poorly understood and likely plays an important role in the formation and evolution, of at least the most massive systems, due to AGN feedback. ... I will give a brief summary of the reverberation mapping technique and describe the important role SkyMapper photometry can play in this program. ...

... The study of the Large-scale structure of the Universe and measurements of the Dark Energy equation of state; The exploration of the growth and cosmological evolution of supermassive Black holes in the Universe. ... In course of the all sky survey SRG will discover about 100 000 galaxy clusters and 3 million AGNs. Galaxy clusters are the largest gravitationally bounded objects in the Universe and are best explored through the study of X-ray emission from the hot intergalactic gas. ... 2016 IKI RAN ...

... 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. 25-29, 2014 . ... SUBJECT: 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. 25-29, 2014 . ... which will be held in Beijing, P.R. China, from August 25-29, 2014, hosted by Chinese Academy of Sciences . ... China), . ... 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. ...