... NGC 1850: Gas Clouds and Star Clusters . ... Summer at the South Pole . ... The December solstice brings the beginning of Winter to Earth's Northern Hemisphere and Summer time to the South! ... Simulated Supergiant Star . ... Consider this "star in a box". Of course, the box is actually a computational box consisting of a three dimensional grid of points, and the star is a virtual one whose physical properties and internal dynamics are numerically simulated at the points on the grid. ...

... 2000 December 24 . NGC 1850: Gas Clouds and Star Clusters . ... Globular clusters as young as NGC 1850 don't exist here. ... Below and right of the main group of stars known as NGC 1850 A is a smaller, still younger group dubbed NGC 1850B . This cluster is made of stars only about four million years old. The large red cloud of gas surrounding the clusters may have been predominantly created by supernovae explosions of stars in the younger cluster. ... About APOD | ...

... Tonight's Sky . ... The Magazine . News . Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Open cluster NGC 2818, spiral galaxy NGC 2964, and spiral galaxy NGC 2976 . ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

... Harald Ebeling, University of Hawaii . A Snapshot Survey of The Most Massive Clusters of Galaxies . Abstract . ... Stephan McCandliss, The Johns Hopkins University . ... HST Imaging of UV emission in Quiescent Early-type Galaxies . ... Distances to Eclipsing M Dwarf Binaries . ... SL2S: The Strong Lensing Legacy Survey . ... Hubble Investigation of Asteroid 21 Lutetia in Support of the Rosetta Mission Flyby . ... GO 11289: SL2S - The Strong Lensing Legacy Survey . ... Past weeks: . ...

... December 13, 1997 . The Coma Cluster of Galaxies . ... The Coma Cluster of Galaxies pictured is one of the densest clusters known - it contains thousands of galaxies . Each of these galaxies house billions of stars - just as our own Milky Way Galaxy does. ... In fact, the Coma Cluster is so big it takes light millions of years just to go from one side to the other! Most galaxies in Coma and other clusters are ellipticals , while most galaxies outside of clusters are spirals . ...

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. ...

... Calendar . ... I n the last day of the International Year of Astronomy ( early evening of 31 December 2009), the Moon had the smallest partial eclipse that we have seen in Ireland and the UK for 40 years: the Moon was 8% covered by the Earth's shadow. Incidentally, this was also a "Blue Moon" - the name given for the second full Moon within a calendar month. ... International Year of Astronomy, Ireland National Node . ...

Astronotes Armagh Planetarium's Stellar Blog! ... Milky Way . Stars . ... This dramatic image depicts Omega Centauri, one of 200 or so globular clusters orbiting our Milky Way galaxy. ... Swarms of tightly packed stars, numbering in the thousands to low millions, globular clusters are cosmic fossils, relics of the early times of our galaxy. Omega Centauri may actually be the core of a smaller galaxy ripped apart and assimilated by our own Milky Way in the distant past. ...