Detection of an inner torus in the Proto planetary Nebulae OH231.8+4.2

J. -F. Desmurs, C. Sanchez Contreras, V. Bujarrabal +2

We performed the first VLBI observations of the SiO v=1 and v=2 J=1--0 masers in a Proto Planetary Nebula OH 231.8+4.2 (also known as the Rotten Egg nebula), at milliarcsecond reso…