Deep Sky Object in Summer
M12 (Globular Cluster in Ophiuchus)
|Date & Time: ||Apr 16 2004, from 24:34 to 24:41 JST(+0900)
|Composed 2 shots with 5 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|
M12 is a medium-sized globular cluster found in the pentagon of a constellation of Ophiuchus.
The cluster is positioned at 3.5 degrees northwest of another globular of M10, and C. Messier discovered M12 just next day when he found M10.
|M12 (NGC6218) / Globular Cluster, type IX|
|R.A.||16h 47m 11.9s (2000.0)|
|Dec.||-01° 57' 00" (2000.0)|
|Real Size||98 light yrs.|
|Distance||19,000 light yrs.|
M12 is a globular that member stars are gathering very sparse, and you will be able to understand the fact if you compare that with M10.
You can appreciate several star-chains are extending outward from the center with about 5 inches telescopes.
Although the Ophiuchus pentagon contains three Messier's Globular clusters, it can be said that you can enjoy the M12 most easily in those.