英仙座的1.2等OC——MEL20！
这可能又是一个被华丽地无视的亮疏散星团——英仙座Alpha移动星团，MEL20（CR39）具体位置图这里就偷个懒，毕竟英仙座大家找起来都没太多困难，作为Alpha星的天船三也一样没问题！
英仙座是完全浸入秋夜银河之中的星座，尤其是α星附近，星星非常密集。请把双筒镜指向α星，以α星中心仔细观察：这里排列着一些较明亮的星，这是称之为英仙座运动星团--Me120的巨大的疏散星团。 （本段文字摘自《28个适于双筒镜观测的天体或天区》）
Alpha Persei Moving Cluster, Mel 20
Open Cluster Melotte 20 (= Collinder 39) in Perseus
The Alpha Persei Moving Cluster
Right Ascension 03 : 22 (h:m)
Declination +49 : (deg:m)
Distance 0.601 (kly)
Visual Brightness 1.2 (mag)
Apparent Dimension 185 (arc min)
Cataloged by Hodierna before 1654.
This moving cluster was probably first cataloged as a nebulous object by
Hodierna. It was described as stellar group by Eddington 1910, and
cataloged by Melotte 1915.
The cluster is rather young and contains a number of massive, hot stars
of spectral type O and B, and thus classified as "OB Association."
The distance of this cluster has recently been measured by ESA's
Hipparcos satellite, as 601 light years (previously, it had been
estimated at 554 light years).
The Alpha Persei cluster is easily found around the star Alpha Persei
(or Algenib, the brightest star in this image, seen in the upper right)
and visible to the naked eye.
The image in this page was obtained by Till Credner on October 14, 2001
at 0:25 UT with a 300 mm f/4.5 telephoto lens, exposed 30 minutes on
Kodak Ektachrome 200/400. The field of view is 4.2 x 5.3 degrees.
以上文字来源：http://seds.org/messier/xtra/ngc/alphaper.html
再补四张！
比较遗憾，最后两张压得太狠了……http://www.kolumbus.fi/jkald/images/alpha_per.jpg
http://zetajanus.webastro.net/astrophotographie/images/amas/melotte-20.jpg
http://gaugg.astronomy.cz/galerie/hvezdokupy/melotte020/Combine002.jpg
http://gaugg.astronomy.cz/galerie/hvezdokupy/melotte020/Combine6.jpg
[ 本帖最后由 Eldghost 于 2007-4-15 22:20 编辑 ] 除了第二张别的没看出来 ::0020:: ::0022:: 顶
恒星团M67
恒星团M67影像提供及版权：Processing - Noel Carboni, Imaging - Greg Parker
说明：聚集在这张清晰天空影像中央的是M67恒星团，是迄今所知道疏散星团中最老星团之一。事实上，尽管疏散星团通常较年轻，但M67内的恒星年龄大约有40亿年，与我们太阳年龄和元素组成相同。疏散星团几乎都比较年轻，因为随时间的推移，当遇到其它恒星，星际云后它们就被驱散开，而当绕我们星系中央运行时会受到潮汐引力的作用。M67包含500多颗恒星，位于巨蟹座内，距离我们大约2,800光年远。根据这个距离，M67大小约12光年。
http://www.bjp.org.cn/files/2007-08/09/F_a0f53d67a7b14e878d91d5ef6b90c063_M67_Greg_Noel.jpg
图文来源：http://www.bjp.org.cn/apod/2007-08/09/content_7804.htm
再来张示意图……
http://oleshko.net.ru/astro/M44-M67.gif
示意图来源：http://oleshko.net.ru/astro/M44-M67.gif
[ 本帖最后由 Eldghost 于 2007-9-1 00:13 编辑 ]