Large solar filament erupts, produces partial halo CME [1]

A large solar filament, which was stretching more than 857 780 km (533 000 miles) last week, finally erupted at approximately 09:25 UTC on February 21, 2015. 

As I feared, #solarstorm [2] launch is huge filament that just rotated backside. STEREO A saw eruption of monster event! pic.twitter.com/ByRoXsMtZE [3]

— Dr. Tamitha Skov (@TamithaSkov) February 21, 2015 [4]

A partial halo CME (or sequence of CMEs) was later observed in SOHO LASCO coronagraph imagery emerging from the southwest. The filament erupted on the farside of the Sun, in the south central portion of the disk.