Explanation: This color "picture" of globular star cluster M55 may not look like any star cluster you've ever seen. Still, it shows a most fundamental view for students of stellar astronomy. 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). Position in the CMD does not correspond to a star's location in the sky, though. Instead, it corresponds to a measured astronomical color, (B-V color) read off the bottom scale, and a brightness in magnitudes (M) on the left hand scale. The temperature for each star can also be found by reading the equivalent scale at the top, where the Sun would have a temperature of 6,000 Kelvins (K). Brightness relative to the Sun's luminosity (Sun = 1) is given on the scale at the right. The globular cluster stars clearly fall into distinct groups dramatically visible in this CMD. The broad swath extending diagonally from the lower right is the cluster's main sequence. A sharp turn toward the upper right hand corner follows the red giant branch while the blue giants are found grouped in the upper left. M55's stars were formed at the same time and at first were all located along the main sequence by mass, lower mass stars at the lower right. Over time, higher mass stars have evolved off the main sequence into red, then blue giants and beyond. The exact position of the sharp turn-off from the main sequence to the red giant branch measures the cluster's age.

<<  Fevral'  >> Pn Vt Sr Cht Pt Sb Vs       1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28         1995   1996   1997 1998   1999   2000 2001   2002   2003 2004   2005   2006 2007   2008   2009 2010   2011   2012 2013   2014   2015 2016   2017   2018 2019   2020   2021 2022   2023   2024

Yanvar' Fevral' Mart Aprel' Mai Iyun' Iyul' Avgust Sentyabr' Oktyabr' Noyabr' Dekabr'

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Publikacii s klyuchevymi slovami: zvezdy - color - magnitude - diagram - cmd - M 55 - star - stellar evolution - cvet - zvezdnaya velichina - diagramma cvet-velichina - Evolyuciya zvezd Publikacii so slovami: zvezdy - color - magnitude - diagram - cmd - M 55 - star - stellar evolution - cvet - zvezdnaya velichina - diagramma cvet-velichina - Evolyuciya zvezd
Sm. takzhe: Chernaya dyra razrushaet zvezdu: animaciya Zvezdy, pyl' i tumannost' v NGC 6559 Pererabotka veshestva v Kassiopee A 25 samyh yarkih zvezd na nochnom nebe 2MASS J17554042+6551277 Golubaya Luna v nasyshennyh cvetah Animaciya: chernaya dyra razrushaet zvezdu Vse publikacii na tu zhe temu >>