... 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. ... NGC 6903: The Butterfly Nebula . ... The Nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud. Curiosity: Wheels on Mars . ... The Eagle Nebula and the Swan Nebula span this broad starscape, a telescopic view of the Sagittarius spiral arm toward the center of our Milky Way galaxy. ...

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! ...

... 2001 February 7 . Distant Open Cluster M103 . ... Explanation: Bright blue stars highlight the open cluster known as M103 . The gas clouds from which these stars condensed has long dispersed. ... In fact, a formerly blue star has recently evolved off the main sequence and is visible above as the red giant star near the cluster center. In general, yellow stars like our Sun are usually less bright and hence less prominent in open clusters than their massive blue cousins. ... About APOD | ...

... 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 . ...

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. ...

... 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. ...

... 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. ...

... Indeed, one alteration of orbits can be the outright ejection of a planet. When several big planets are orbiting a star under each other's influence, the system is inherently unstable. ... We know of no good reason why the smallest objects with fusion should have the same mass as the smallest objects that can form by themselves. ... 6) Mission Definition . ... I don't think this mission is impossible, and will suggest a definition in a future article in Mercury. ... Good luck! . ...

... Weidong Li, University of California - Berkeley . ... Abstract . ... A Snapshot Survey of The Most Massive Clusters of Galaxies . ... Keith S. Noll, Space Telescope Science Institute . ... Increasing the Accuracy of HST Astrometry with FGS1r . ... Satellite Search for Dawn Mission Targets, Vesta and Ceres . ... HST Observations of Titan's Escaping Atmosphere in Transit and in Emission . ... GO 11969: Satellite Search for Dawn Mission Targets, Vesta and Ceres . ... Past weeks: . ...

... ESO, the European Southern Observatory . ... Travel and Contacts . Travel to ESO Headquarters . ... ESO Acronyms . ... Survey Telescopes . ... Galaxy Clusters . ... Star Clusters . ... Stars@ESO . ... ESO 3.6-metre telescope . ... This video pan sequence gives a close-up view of one of the brightest star clusters in the sky. This image from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESOтАЩs La Silla Observatory in Chile, shows Messier 7, also known as NGC 6475. ... 180.0€аMB . ...

... 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) ...

... 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. ...

. Mars has become the center of intense interest since the Martian Meteorite results were announced. Currently there is a lively debate whether or not primitive life formed there or not.

Saturn: The beauty of the rings. Saturn . ... Belongs to the giant planets . It has no definite solid surface. ... The free fall acceleration at the Saturn surface near equator is 9,06 m/s^2 . ... In the centre of the planet the temperature is about 20000K. The satellites . ... The rings of Saturn . ... It is proved that Saturn's rings (as well as the other planet's) are the fragments of the great cloud being near the planet with million kilometres length (see how the rings were formed ). ...

... 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. ...

Advisor's project abstract: . How do stars form? ... The fact that stars form in dense clusters raises the possibility that interactions between stars may govern the process of star and planet formation. ... As a project, the student will be assigned a star forming region in the Orion molecular cloud containing a cluster of young stars. ... A summer intern will also carry out diagnostics studies of the stellar activity and variability using the results from these simulations. ... Abstract: . ...

... In the past used to check pn/ MOS cross calibration Example of old vs new pn/ mos Residuals in the form of ratio data / model for PN data on MOS best fitting model Example of old vs new pn/ mos Residuals in the form of ratio data / model for PN data on MOS best fitting model ACIS S3 vs EPIC pn · · Same thing, only now we compare Chandra ACIS S3 with ... Flux cross-cal · · The new HRMA calibration impacts on the ACIS/EPIC flux cross calibration. ...

THE PHOTOMETRIC RESEARCHS OF THE MERCURY'S SURFACE BY MEANS OF DIGITAL MODELS. ... The surface brightness of Mercury was measured Danjon (1933, 1949, 1953) and Harris (1961) in phase angle 3o-123o. The analysis of the various data of the integral photometric gives the results of determination of the main photometric constants for Mercury. ... THE PHOTOMETRIC RESEARCHS OF THE MERCURY'S SURFACE: S.G. Pugacheva The surface brightness of the Mercurian images was established on the geologic map Mercury. ...

... 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. ...

... B ut Europa's surface is not at all like anything in the inner solar system. ... T he images of Europa's surface strongly resemble images of sea ice on Earth. It is possible that beneath Europa's surface ice there is a layer of liquid water , perhaps as much as 50 km deep, kept liquid by tidally generated heat. ... It is most likely generated by sunlight and charged particles hitting Europa's icy surface producing water vapor which is subsequently split into hydrogen and oxygen. ...