Astronomy Picture of the Day . Clusters and Nebulae of the Hexagon . ... But placing your cursor over the picture will reveal the hexagon's outlines and the bright clusters and nebulae along a stunning portion of the Milky Way opposite the galactic center . The celestial highlights include M42 (aka the Great Nebula of Orion), Orion's Horsehead nebula, the Rosette and Cone nebulae, and nearby star clusters M45 (Pleiades) and Gemini's own M35 . ... Publications with keywords: nebula - cluster . ...

Today's APOD | ... Editor's choices for the most educational Astronomy Pictures of the Day about open clusters: . APOD: 2006 January 9 - M45: The Pleiades Star Cluster . ... The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. ... Two types of star clusters are visible in our Milky Way Galaxy : open clusters and globular clusters . ... Aged 80 million years, M47 is a smaller but looser cluster of about 50 stars spanning 10 light-years. ... Index | ...

... STScI-PRC00-25 A DYING STAR IN GLOBULAR CLUSTER M15 The globular cluster Messier 15 is shown in this color image obtained with the NASA Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2). ... Known as Kuestner 648, this was the first planetary nebula to be identified in a globular cluster. ... At the present time, the most massive stars remaining in M15 have about 80 percent of the mass of our Sun, a fact that makes the existence of a planetary nebula like K 648 something of a mystery. ...

... Tonight's Sky . ... The Magazine . ... Observing . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... Bright planets meet at dusk . ... Astronomy magazine subscribers can read the full article for free. ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter....

Photon Scattering: Basic Principle of Photon Scattering . Audio Narration is available . No Scattering: Photon Source and Detector . ... For optical photons, scattering goes as wavelength to the -4 power. In the case of blue photons compared to red photons, this means that blue photons are about 10 times more likely to get scattered than red photons. ... Watch the blue photons scatter away from the detector . ... Interstellar dust make stars appear redder than they really are . ...

GALAXIES cenA .tiff 40 Bright Radio Galaxy M31.tiff Nikon Andromeda Galaxy (note HII regions in spiral arms) ngc6744.tiff 40 NGC 6744 a face-on spiral clouds_20d.tiff H'blad The Magellanic Clouds our nearest neighbours Lmc_7.tiff Nikon The Large Magellanic Clouds Lmc_zoom.tiff Nikon Detail of previous image smc_7.tiff Nikon The Small Magellanic Clouds smc-zoom.tiff Nikon Detail of previous image 30dor_40_BVR.tiff 40 The 30 Dor ... B [OIII] Halpha trifid.tiff 40" The Trifid Nebula. ...

... The Pleiades star cluster, also known as the Seven Sisters and Messier 45, is a conspicuous object in the night sky with a prominent place in ancient mythology . ... The stars in the Pleiades are thought to have formed together around 100 million years ago, making them 1/50th the age of our sun, and they lie some 130 parsecs (425 light years ) away. ... Data for these stars are listed in a table below. ... Yes . ... WEBDA Pleiades cluster data . ... M45: The Pleiades Star Cluster (2007 November 18) ...

ATMoB "Open Cluster Observing Award " Guidelines Purpose: To promote observing among the membership of the Amateur Telescope Makers of Boston through participation in the Open Clusters Observing Awards program. Introduction: This awards program is oriented towards visually observing open clusters above magnitude 9.9. ... It turns out that a very unprejudiced and convenient method to dermine the limiting magnitude is to count the number of visible stars in certain areas on the sky. ...

... We still have a long distance to cover before we leave the Milky Way Galaxy -- tens of thousands of lightyears, as a matter of fact -- so let's stop by some interesting objects on the way. ... But we have reached the edge of the Milky Way Galaxy. ... We don't know, but we do know that there are countless voyages left to take. To continue the virtual voyage beyond our galaxy, go to Kent Cheatham's "A Walk in the Stars" at http://www.ionet.net/~cheatham/astro/astrotour.shtml . ...

... Science User Portal . ... ESO, the European Southern Observatory . ... Travel and Contacts . Travel to ESO Headquarters . ... Survey Telescopes . ... Star Clusters . ... FLAMES . ... 100 Hours of Astronomy . ... IMAX€о 3D Film Hidden Universe . ... This image, the first to be released publicly from VISTA, the worldтАЩs largest survey telescope, shows the spectacular star-forming region known as the Flame Nebula, or NGC 2024, in the constellation of Orion (the Hunter) and its surroundings. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Stars . ... Starbursts are short-lived events, stars are forming so quickly that the reservoirs of interstellar gas from which stars are coalescing would be used up on a timescale much shorter than the age of the galaxy . ... Strong stellar winds from giant new stars in the starburst region combine with the blasts of supernovae to push a mighty flood of extremely hot gas, a ?superwind? from the galaxy thousands of light years into intergalactic space. ...

... We have made observations of the Perseus cluster with the Westerbork Telescope at 610 MHz. ... Several newly detected sources are identified with cluster galaxies. ... No evidence is found for the existence of the previously reported ~ 65'x25' cluster halo, 3C 84B. Key words: radio galaxies - clusters - tailed radio sources buoyancy The Perseus Cluster of galaxies is one of the most fascinating systems accessible to extragalactic astronomers. ...

... 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 ...

Feb 28 2016 Cepheus - The King IC 455 5mm TV VF,VS,OVAL, NND ,R=F Galaxy S0 Nov 16 2012 18 IC 469 5mm TV Galaxy SAB(rs)ab: VF,VS,OVAL,VEXT, NND ,AV2,R=F Nov 16 2012 18 IC 1396 19mmW 25mmPL Open Cluster II3mn **STARS,BRIGHT, NICE DUST LANES,R=G DECENT NIGHT - MEGASTAR CONTROL Sep 07 2005 8 May 22 2004 8 NGC 40 7.5mmW 7.5mmW H58-4 MB,R,R=G Planetary Neb 3b+3 F,VS,R,VSMBM,*12SP Nov 11 2009 12 Oct 06 ... 13 Jul 24 2006 8" Aug 21 2004 8" PB,CS,R=F CLEAR SKIES - H.H. LITE. ...

... This paper ( Burke et al. 2003 ) describes the creation of one such catalogue - the Southern Serendipitous High-redshift Archival ROSAT Cluster (SHARC) survey - which covers an area of 17.7 deg 2 and consists of 32 clusters with redshifts between 0.05 and 0.7 and X-ray luminosities between 7 x 10 42 and 4 x 10 44 erg/s: the high-redshift subsample contains 16 clusters with = 0.3 and X-ray luminosities greater than 2 x 10 43 erg/s (luminosities are quoted for the 0.5 - 2.0 keV energy band). ... 1997 ...

... HST Phase II Proposal Instructions for Cycle 20 > Chapter 3: Fixed and Generic Targets > 3.3 Target Category and Target Description [Description] . ... Each target must be assigned a single primary category from Table 3.2 , and at least one descriptive keyword , chosen from the appropriate Table 3.3 through Table 3.9 (see Table 3.2 for which table is appropriate for each category). ... Table 3.3: Descriptive Keywords for STAR and EXT-STAR . ... Table 3.6: Descriptive Keywords for CLUSTER OF GALAXIES...

... 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. ...

... Structure of Data . ... Catalog . ... In SAI OCL Catalog, we introduce our work on investigation of the Milky Way system of open star clusters. The main goal of our study is a search for new clusters using huge surveys. 168 new clusters have been already discovered by us using J,H,Ks data from 2MASS point source catalog. ... For 141 new clusters, we found their physical parameters using J,H,Ks data from 2MASS catalog and, for a number of clusters, our UBVRI CCD observational magnitudes. ...

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

... In typical nightly use, the wide field and planetary telescope and cameras record images of favorably placed objects in the sky, including constellations, bright variable stars, nebulae through narrow-band filters, comets, the Moon, and planets. ... Shared Skies telescopes are available for use by students at the University of Louisville and the University of Southern Queensland, and by teachers and students in middle and high schools mentored by faculty at the universities. ...