... 2015 April 17 . M46 Plus Two . ... Explanation: Galactic or open star clusters are young. ... In this pretty starscape, the colorful, circular patch above and right of the center of M46 is the planetary nebula NGC 2438. ... NGC 2438 is estimated to be only 3,000 light-years distant, though, and moves at a different speed than M46 cluster members. Along with its fainter cohort, planetary nebula NGC 2438 is likely only by chance appearing near our line-of-sight to the young stars of M46. ...

M46 And NGC 2438: Young And Old . ... Credit Copyright: Wil Milan Explanation: Galactic or open star clusters are relatively young. ... Located about 5,000 light-years away toward the constellation Puppis , M46 is a familiar object to telescopic stargazers and also seems to contain a contradiction to its youthful status. ... In fact, NGC 2438 is estimated to be only 3,000 light-years distant and moves at a different speed than M46 cluster members. ... NASA Official: Jay Norris. ...

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. ...

... 2000 August 4 . M15: Dense Globular Star Cluster . ... In fact, only 40,000 light-years away in the constellation Pegasus, M15 is one of the most densely packed globular star clusters in our Milky Way Galaxy. This stunning Hubble Space Telescope image of M15 shows thousands of individual stars across the central 10 or so light-years of the cluster, also cataloged as NGC 7078. ... Globular star clusters harbor from a hundred thousand up to a million stars and roam the Milky Way halo. ...

... Answer: Stars live different lengths of time, depending on how massive they are. ... All stars age at different rates, depending on how massive they are at the start their lives. The stars in this photograph are part of an open star cluster called NGC 3293, containing around 50 stars that were all born around the same time. ... Each star in this cluster is much more massive than our own. ... This is a gigantic Red Giant star, around six and a half times larger than the Sun! ...

... 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) ...

... 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. ...

... Kalirai and Harvey Richer of the University of British Columbia led the study, which began as an investigation of a globular star cluster in the Milky Way galaxy known as NGC 6397. ... Within the population of stars and galaxies behind NGC 6397, the Hubble image revealed a large elliptical galaxy that contains several hundred globular clusters. ... In fact, a single giant star in NGC 6397 appears 10 million times brighter than one of the distant globular clusters. ...

Next: J.E. Chambers, Research Astronomer Up: Research Previous: Research Contents . ... Solar Variability and Climate . Other Activities . ... Applied to data of flares on Gliese866 he was able to estimate the area of hydrogen emitting flare regions as 1-13% of the stellar surface. ... As partners in the project, Armagh Observatory has been asked to contribute to the selection process in exchange for priority access to the data which will eventually flow from the satellite. ...

... Observing . ... Solar Observing . ... April 3 (SUN) - Solar Observing, Central Park , Manhattan . ... APRIL'S SKY . ... Lecture Series at the American Museum of Natural History The Amateur Astronomers Association is proud to present an astronomy lecture series from October through May each year for our members and the .. ... The€аAmateur Astronomers Association of New York€аwas organized in 1927 to promote the study of Astronomy, emphasizing its cultural and inspirational value. ...

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. ...

This page contains the table of contents and select excerpts only and is not a complete reproduction of this issue. Complete content for online Mercury is available to ASP members and institutional subscribers . ... As Indiana University astronomer John Salzer well knows, not all of them are easy to classify, and a few even appear to be relics from a bygone age. ... But at the same time, Johannes Kepler made a fundamental contribution to astronomy. ... A Messenger to Mercury , Paul Deans . ...

This huge elliptical galaxy NGC 5128 (Centaurus A) is the closest such galaxy to Earth, at a distance of about 12 million light-years. Observations with ESO s Very Large Telescope in Chile have discovered a new class of dark globular star clusters around this galaxy. ... Normal globulars are marked in blue and globulars showing similar properties to dwarf galaxies are in green. The dark globulars appear very similar to other globulars around this galaxy but contain much more mass. ...

In order to measure the density of the Universe, it is necessary to sample a region that is larger than the scale on which the Universe becomes approximately homogeneous. ... When applied to clusters of galaxies we find a mass to luminosity ratio that implies a density of the Universe that is about 0.3 times the critical density. ... Thus the mass-to-muinosity ratio appears to vary with the size of the region measured, from 3 in the solar neighborhood to 30 in galaxies to 300 in clusters of galaxies. ...

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! ...

... 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. ...

... Astrophysics Group . ... AMI Science . ... Observations of galaxy clusters are central to the AMI science programme. The AMI Small Array is used to observe already-known clusters with high-sensitivity and resolution, allowing us to extract detailed information about individual clusters and to build up statistics about the cluster population. ... Observing galaxy clusters at 15 GHz is tricky because of the contamination from foreground radio sources, which is where the Large Array comes in! ...

ABSOLUTE PROPER MOTIONS OF 331 OPEN CLUSTERS . ... The proper motions of stars in the fields of 331 open clusters were taken from Four-Million Star Catalog (4M-catalog) of positions and proper motions (Volchkov et al. ... The absolute proper motions for 21 young open clusters have been derived by comparison of precise relative proper motions of individual stars and their corresponding absolute proper motions. ... Sign of proper motions in RA . ... 0.0001 arcsec/yr . ... rms error in RA proper motion . ...

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. ...

... About ATNF overview . ... Parkes | ... A star cluster is a group of stars that share a common origin and are gravitationally bound for some length of time. ... The two basic categories of stellar clusters are open clusters, also known as galactic clusters, and globular clusters. ... Open clusters are so-named due to the fact that the individual component stars are easily resolved through a telescope. ... M67, a very old open cluster has no star hotter than +0.4 colour index left on the main sequence...