... Color-Magnitude Diagrams Triangles: objects located less than 30" from cluster center Squares: objects located less than 60" from cluster center Dots: field objects (more than 150" from center) Hollow symbols: stars Highlighted: the red sequence for each cluster Observed in the Near Infrared .. ... BCG magnitude X = clusters presented here O = clusters in literature with 0.8<z<1.2 5 of 10 x-ray sources were confirmed with a red sequence detection RXJ1205 Color suggests redshift about 1. ...

... Spiral galaxies viewed face-on display a grand design, with graceful spiral arms traced by bright star clusters and glowing stellar nurseries. ... Space Station Shows Off New Robot Arm . ... GRO J1655 40: Evidence for a Spinning Black Hole . ... In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole. ... The Orion Nebula is a nuturing stellar nursery filled with hot young stars and their natal clouds of gas and dust. ...

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 | ...

Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

... 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. ...

... Archives . ... my first AAS. ... I was questioned by two attendees, acquainted before the AAS, if I can suggest them clustering methods relevant to their projects. ... classification vs. clustering or supervised learning vs. unsupervised learning : the former terms from the pairs indicate the fact that the scientist already knows types of objects in his hands. ... Tags: Classification , clustering , cosmology , spatial statistics , supervised learning , test , unsupervised learning . ...

... We present a photometric and spectroscopic study of the unique isolated nearby galaxy KKR25. The isolated dwarf spheroidal (dSph) galaxy KKR25 was discovered by Karachentseva, Karachentsev Richter (1999, A , 135, 221) during the search of dwarf galaxies in the direction of the Local Void. In spite of its isolation KKR 25 has no gas and looks like a normal dwarf spheroidal system. ... This is the first known planetary nebula in a dwarf spheroidal galaxy outside the Local Group. ...

... 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. ...

... 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. ...

... 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 ...

. The X-ray brightness of galaxy cluster Abell 754 is color-coded, with white indicating its brightest and densest parts and purple the dimmest and most tenuous. The white blob is core gas from the more massive cluster involved in the collision. The purple contour's shape likely reflects an earlier collision within Abell 754, and therefore, its outline doesn't match the ongoing crash in the center. ESA/ XMM-Newton/ Patrick Henry et al.

Astronotes Armagh Planetarium's Stellar Blog! ... Comets and Asteroids . ... Image credit:ESO/J.Emerson/VISTA. ... However others are less pessimistic and it has even been claimed that the mysterious ?Wow! signal? received in 1977 originated from the direction M55.б  Sadly, this still unexplained pulse of radio energy originated from a location rather to the northwest of M55 so I doubt if the source was this cluster (if indeed the signal was genuinely of extraterrestrial origin). ... Mysterious Wow! ...

... We describe a tool in the PCIPS environment for finishing the job of globular cluster photometry started by DAOPHOT II: starting with the instrumental magnitudes derived by DAOPHOT II, DASHA can automatically produce final color-magnitude diagrams. ... DASHA can automate the whole process of globular cluster photometry, from instrumental magnitude lists produced by DAOPHOT II, to final color-magnitude diagrams. ... DASHA is oriented towards star lists produced by DAOPHOT II as source data. ...

... Future seminars . P a s t seminars . Seminar council . Stability of cold fronts in clusters of galaxies " . E. Churazov (IKI, MPA) . ... One of the insteresting results of Chandra and XMM-Newton observatories is the discovery of sharp structures in the X-ray surface brightness of galaxy clusters. These structures (a.k.a. cold fronts) are likely associated with the contacted discontinuities formed when a hot gas flows over a colder gravitationally bound gas cloud. ...

... BLUE STRAGGLER STARS are unusually hot and bright stars found in the cores of ancient star clusters known as globulars. ... BACKGROUND (from wikipedia): Blue straggler stars are stars in open or globular clusters that are hotter and bluer than other cluster stars having the same luminosity. ... There is evidence in favor of this view, notably that blue straggler stars appear to be much more common in dense regions of clusters, especially in the cores of globular clusters. ...

... 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) ...

Collins School Star Party - Oct. 5, 1999 Presented by the North Shore Amateur Astronomy Club (NSAAC) For more information: NSAAC: http://www.star.net/people/~nsaac 1.0 Using a telescope Close one eye (use your hand if it's easier) and look straight down into the eyepiece. ... Massive stars use up their fuel much faster - in some cases less than 100 million years. ... Jupiter _____. ... With the chart at left and using the brightest stars as a guide, see if you can find Uranus with binoculars. ...

... Cancellation occurs. ... The cancellation in this small region exists until 08:00 when all the negative fragments disappeared, but rarely see any X-ray response. 02:30 Many small positive fragments emerge at south. Then they become stronger and move toward the preexisting positive ones to form a bigger one. A cluster of negative fragments with some weak positive ones nearby present at the south. ... Some other negative fragments moving from north of the positive one start to take action. ...

... LMC Project Outline . NGC 1818 Initial Results . ... The Large Magellanic Cloud (LMC) is uniquely suitable for the study of massive star clusters at all stages of evolution. By combining HST observations of these clusters with N-body models we hope to understand the origin and evolution of rich star clusters in our own Galaxy, in the LMC, and beyond. ... We aim to combine our HST observations with N-body models to understand the formation and evolution of globular clusters. ...

You Can Make Stellar Images Brighter . Articles | ... A few months ago I wrote an article titled "You Can’t Make Them Brighter". So why am I now writing that you can make them brighter. ... The image of a focused star is actually a small disk called the Airy disk, named after the 19 th century scientist Sir George Airy. ... For a given aperture, a smaller Airy disk means that the light is focused to a smaller disk and is therefore brighter. ... www.astronomy.net . About Astronomy Net | ...