Deep Sky Object in Summer
M11 (Open Cluster in Scutum)
|Date & Time: ||May 9 2003, from 26:35 to 26:50 JST(+0900)
|Composed 3 shots with 6 minutes exposed|
|Optical: ||Meade 25cm(10") Schmidt-Cassegrain with conversion lens (f=1600mm, F6.3)
|Auto-guided with Meade LX200 Equatorial & Pictor 201XT
|Digital Camera: ||Fujifilm FinePix S2 Pro
|Location: ||Ooizumi vil., Yamanashi pref.
|Camera Settings: ||Recording Format...12bit CCD-RAW, converted to 16bit TIFF(3024×2016)|
|CCD Sensitivity...ISO1600, White Balance...Auto|
The Scutum is a tiny constellation just North of Sagittarius,
and M11 (NGC6705) is a fine open cluster found out in this minor constellation.
This object has no name in Japan, but it's called "Wild Duck Cluster" in English.
|M11 (NGC6705) / Open Cluster, type g, I 2 r|
|R.A.||18h 51m 5.9s (2000.0)|
|Dec.||-06° 16' 00" (2000.0)|
|Real Size||16 light yrs.|
|# of Stars||682|
|Distance||5670 light yrs.|
M11 is positioned in the Milky Way where fine stars are extremely crowded,
but it's unexpectedly easy to find the cluster because M11 is much denser than the Milky Way of a background.
Each open cluster has one of five types of "c" to "g" classified with its density,
and M11 has the highest index of "g", so it looks like a globular cluster.
The cluster consists of about 200 stars and 5600 light years away.