Astronomy Picture of the Day . ... B.J. Mochejska , J. Kaluzny ( CAMK ), 1m Swope Telescope Explanation: This color "picture" of globular star cluster M55 may not look like any star cluster you've ever seen. ... In the picture, a Color Magnitude Diagram (CMD), M55's individual stars are represented as dots whose color indicates relative temperature, red (cool) to blue (hot). ... Publications with keywords: color - magnitude - diagram - cmd - m55 - star - stellar evolution . ...

... 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 | ...

Fundamental parameters and time evolution of mass loss are investigated for post-main-sequence stars in the Galactic globular cluster 47 Tucanae (NGC 104). ... We confirm the cluster's distance as d = 4611+213 -200 pc and age as 12 ТБ 1 Gyr. Horizontal branch models appear to confirm that no more red giant branch mass loss occurs in 47 Tuc than in the more metal-poor Я? Centauri, though difficulties arise due to inconsistencies between the models. ...

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. ...

... About ATMoB . ... The Observing Committee is starting an Observing Awards Program to promote observing among the membership of the Amateur Telescope Makers of Boston. ... Participant must be a current member of the Amateur Telescope Makers of Boston . ... To qualify for your Observing Award Certificate, turn in your worksheet and drawings to an ATMoB Observing Committee member or observing@atmob.org . ... This Excel sheet has useful macros. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... Stellar cinders . Born-again stars . ... Heavyweight Stars . ... What will happen inside the Sun and why? ... These are questions about "stellar evolution", the history of stars as they are transformed by nuclear processes deep inside. ... Most of what we know about stellar evolution comes from computer models of stars. ... We learn about the evolution of high-mass stars from HR diagrams of young galactic open clusters, and the evolution of low-mass metal-poor stars from old globular clusters. ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. February 5, 1996 . COBE Dipole: Speeding Through the Universe . Credit: NASA , COBE , DMR , Four-Year Sky Map . ... The Milky Way Galaxy orbits in the Local Group . ... The map indicates that the Local Group moves at about 600 kilometers per second relative to this primordial radiation . ... About APOD | ...

Regions designation | Regions models | ASCII files description . The real time visibility of the IB_TAIL relative to the Evpatoria and Panska Ves . ... The real time regions passing . ... The IB_TAIL geocentric distance as a function of the Moscow time (MT = UT + 3h) (Plot) . Geomagnetic local time in the IB_TAIL position as a function of the MT (Plot) . The IB_TAIL orbital data ASCII files . ... INTERBALL mission  ...

... 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) ...

... The exercises are now available on the web and in six booklets (100 pages in total), titled: . ... Exercise 1: Measuring the Distance to Supernova 1987A", . Exercise 2: The Distance to Messier 100 as Determined by Cepheid Variable Stars", . Exercise 3: Measuring the Distance to the Cat's Eye Nebula" and . Exercise 4: Measuring a Globular Star Cluster's Distance and Age". ... More exercises will follow in the future. ... Exercise 3 - Measuring the Distance to the Cat's Eye Nebula . ...

Giant stars are rare because . ... In a color-magnitude diagram of a star cluster, the blue end of the main sequence is useful for defining the age of the cluster because . a) blue stars are not affected by extinction and reddening by dust. b) stars just slightly brighter and redder are just now evolving off the main sequence to become giants. c) older, metal-poor stars are blue. d) the hottest stars are the oldest stars in a cluster. ... 2) Some idea. 3) Good idea. ...

... 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 gala