Deep Sky Object in Summer
M55 (Globular Cluster in Sagittarius)
|Date & Time: ||May 11 2007, from 26:36 to 26:50 JST(+0900)
|Composed 4 shots with 4 minutes exposed|
|Optical: ||TAKAHASHI 12.5cm(4.9") fluorite refractor (f=1000mm, F8.0)
|Auto-guided with VIXEN ATLUX Equatorial & Meade Pictor 201XT
|Digital Camera: ||Fujifilm FinePix S2 Pro
|Location: ||Ooizumi, Hokuto city, Yamanashi pref.
|Camera Settings: ||Recording Format...12bit CCD-RAW, converted to 16bit TIFF(3024×2016)|
|CCD Sensitivity...ISO1600, White Balance...Auto|
M55 (NGC6809) is a sparse globular cluster a bit far to east from the Milky Way in Sagittarius.
The cluster can be found by stretching a line from sigma to tau Sgr., has a magnitude of about 7.6, you can see it with binoculars.
|M55 (NGC6809) / Globular Cluster, type XI|
|R.A.||19h 40m 0.0s (2000.0)|
|Dec.||-30° 58' 00" (2000.0)|
|Real Size||81 light yrs.|
|Distance||19,000 light yrs.|
You can see this picture that the individual stars in M55 are almost perfectly resolved;
actually the cluster is less concentrated than almost all of other globular clusters.