Huge Dark Object around the Sun - Sept 5, 2013

An interesting dark object caught on SOHO Lasco C3.

What is this object?

Is it a giant cloaked UFO like the 'invisible' UFO from last year (2012-03-09)? A planet or the Sun has an invisible partner?

If you going to look this up on SOHO go from 20130903 to 20130906 you will see this dark object appear and it still in the same spot as it has been for days.