... 2011 February 25 . NGC 4449: Close-up of a Small Galaxy . Credit: Data - Hubble Legacy Archive , ESA , NASA ; Processing - Robert Gendler . ... But small irregular galaxies form stars too, like NGC 4449 , about 12 million light-years distant. ... NGC 4449 is a member of a group of galaxies found in the constellation Canes Venatici. Interactions with the nearby galaxies are thought to have influenced star formation in NGC 4449. ... About APOD | ... A service of: ASD at NASA / GSFC . ...

... Many bright nebulae and star clusters in planet Earth's sky are associated with the name of astronomer Charles Messier, from his famous 18th century catalog. ... This colorful cosmic portrait features glowing gas and dark dust clouds in IC 1795, a star forming region in the northern constellation Cassiopeia. ... The Double Cluster . ... Also cataloged as NGC 869 (right) and NGC 884, both clusters are about 7,000 light-years away and contain stars much younger and hotter than the Sun. ...

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! ...

... 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. ...

home publications > mercury . ... Big Clusters, Tiny Galaxies . ... Astronomers struggle to understand why giant star clusters form in the tiniest of galaxies . ... These clusters are probably young versions of globular clusters, but they are commonly called super star clusters. Seven dwarf galaxies within 16 million light-years have formed super star clusters, with one of these galaxies, NGC 1569, possessing two young clusters. ... Super star clusters have a lot to tell us about star formation. ...

Many intermediate-age star clusters in the Magellanic Clouds exhibit very unusual features in their colour-magnitude diagrams that suggest they may have formed their stars over periods spanning hundreds of millions of years per cluster. ... Nonetheless, this interpretation is enticing in the context of the formation of ancient globular clusters, which almost always exhibit puzzling abundance patterns that apparently require multiple episodes of star formation to explain. ...

... Most stars form in clusters, so the simple picture of star formation needs to incorporate the impact that young stars have on their environments, and each other. One region we study is NGC 1333, shown to the left as seen by the Spitzer Space Telescope. This is a тАЬproto-typicalтАЭ star-forming region located тАЬonlyтАЭ 1000 light years away in the direction of the constellation Perseus. ... Copyright 2015 Adele Plunkett. ...

... 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....

... Bad Astronomy . ... Bitesize Astronomy . ... The next step up are true clusters, called open clusters . Open clusters (sometimes misleadingly called "galactic clusters") are groups of stars ranging in size from a few dozen stars up to tens of thousands. ... The youngest is about 1 or 2 million years old, while the oldest is about 6 or 7 billion years, making it just older than our own solar system. ... So by looking at the stars in the cluster we can tell pretty well how old they are. ...

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. ...

... The routines implemented are CLUSTER which has 8 options for hierarchical clustering and PARTITION which carries out non--hierarchical clustering. ... The former is non--hierarchical clustering or partitioning. The latter is hierarchical clustering. Brief consideration will show that a sequence of n-1 agglomerations are needed to successively merge the two closest objects and/or clusters at each stage, so that we have a set of n (singleton) clusters, n-1 clusters, ..., 2 clusters, 1 cluster. ...

... 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 . ...

... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Astronomy for Kids . ... Astronomy 101 . ... Astronomy Foundation . ... Do globular clusters form in a galaxy's halo or migrate in from outside? If the latter, how? ... The Milky Way Galaxy has a system of roughly 150 globular clusters, which are all older than 9 billion years. ... Get instant access to subscriber content on Astronomy.com! ... If you are already registered on Astronomy.com, please log in below. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . Portrait of Sir William Herschel (1738-1822) Royal Astronomical Society . Probably the most famous astronomer of the 18th century, Sir William Herschel discovered, in addition to the planet Uranus, many new nebulae, clusters of stars and binary stars. ... Other Herschel Family Portraits . Mirror by Herschel . Return to A Short History of Armagh Observatory . Last Revised: 2009 November 23rd . ...

A Canadian and American team of Astronomers have used the 305-m wide Arecibo radio dish, the world's largest and most sensitive radio telescope, to uncover a dozen new super-fast-spinning pulsars. The team directed their search for these rare and exotic stars by pointing the Arecibo radio telescope towards massive star clusters, called Globular Clusters, orbiting our Milky Way galaxy. ... One of the most exotic residents in the Globular cluster system are the millisecond pulsars. ...

Laboratory of Stellar Physics . ... A study of close binaries with black holes, neutron stars and white dwarfs. ... A study of SS433 - the massive close binary with a black hole in the regime of supercritical accretion . ... A search for intermediate-mass black holes (IMBH). The black holes which are not supermassive black holes observed in quasars, and which were formed not in massive stars. ... A search for new magnetic stars, new CP stars, measurements of magnetic fields in stars . ...

8th of February 2015 . International Year of Light 2015 . High resolution radio emission from RCW 49 . ... Benaglia et al. (2013) analyse Molonglo 843 MHz and ATCA 5.5 / 9 GHz radio continuum data. They find two radio shells closely matching the Spitzer infrared emission, showing pillars, filaments and a bright bridge. The image shows the ATCA 9 GHz radio continuum emission in red , the Spitzer 3.6 micron emission in blue and the Spitzer 8 micron emission in green . ... today * ATNF | ...

... With the stars gamma Can and delta Can , it forms another asterisms called " the Asses and the Manger ". ... Formed by the stars delta Ori, epsilon Ori and zeta Ori ; in Latin America it is called the " Three Marys ". ... Built by the four stars alpha UMa, beta UMa, gamma UMa and delta UMa . ... Formed by the four stars alpha Del , beta Del , gamma Del and delta Del . ... Also on Orion; the belt stars ( delta Ori , epsilon Ori and zeta Ori ), the sword and eta Ori build up this asterism. ...

... Tadpole Emission Nebula and the Flaming Star Nebula . The constellation of Auriga harbors the cluster NGC 1893 which contains the Tadpole Nebula (IC 410). ... The Flaming Star Nebula, IC 405, is the magenta/purplish area and is the reflection portion of this nebulous region. 5nm Narrowband filters; H-alpha: O-III: S-II - 60: 60: 40 minutes x 600-second sub frames, Total= 2-hours 40-minutes, binned 1x1. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... 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. ...