Brief Description   This emphasized image shows the extent of solar corona observed on Aug 21, 2017 at Oregon, USA. The celestial north direction has been turned upward with a view angle of 4.3°×2.4°. A bright star in left edge is the Regulus in Leo. The streamline structure of corona is reflecting the distrubution of solar magnetic field.

Photography Condition
Date & Time... Aug 21 2017, from 10:17:59 to 10:18:35 PDT(-0700), 1/8000, 1/1000, 1/125, 1/15, 1/2sec. exposed
   24 shots are HDR composed, rotational masking processed (Rotation angle: 4°)
Optical... BORG 60ED with a correction lens (f=378mm, F6.3)
   Auto-guided with EYEBELL CD-1 portable Equatorial
Digital Camera... Nikon D810A
   (ISO200&800, recorded in 14bit CCD-RAW)
Location... Salem, Oregon, USA