Preliminary results on SiO v=3 J=1−0 maser emission from AGB stars

Paper i proceeding, 2012

We present the results of SiO maser observations at 43 GHz toward two AGB stars using the VLBA. Our preliminary results on the relative positions of the different J=1–0 SiO masers (v=1,2 and 3) indicate that the current ideas on SiO maser pumping could be wrong at some fundamental level. A deep revision of the SiO pumping models could be necessary.