Precessing Warped Be Disk Triggering the Giant Outbursts in 2009 and 2011 in A 0535+262/V725 Tau

Yuki Moritani, Daisaku Nogami, Atsuo T. Okazaki +8

We carried out optical high-dispersion spectroscopic monitoring of the Be disk in a Be/X-ray binary A 0535+262/V725 Tau from 2009 to 2012, covering two giant outbursts and several…