Resolving discrepancy in the pPN OH 231.8+4.2
Paper i proceeding, 2018

OH 231.8+4.2 is an archetypal pre-planetary nebulae (pPN). It’s a binary system surrounded by bipolar nebula. Some years ago the authors extensively studied it and performed several VLBI observations from which they obtained mas-resolution maps of the SiO (7 mm) and H2O (1.3 cm) maser emissions (see [7]). H2O masers were found to be distributed in two areas along the symmetry axis of the nebulae oriented nearly north-south delineating a bipolar outflow and their astrometric positions were accurately measured. SiO masers, indicating the position of the Mira component of the binary system, form a structure perpendicular to the axis of the nebulae. The general picture of the source looked satisfactory, except for the relative position of the two masers. Surprisingly, SiO masers, were tentatively placed 250 mas away (370 AU) from the apparent center of the outflow. Using the ALMA we observed the SiO maser emission at 86 GHz and accurately derived the position of the Mira component. Combining our previous VLBA data and our new ALMA observations we are now able to give a more complete and detailed description of the inner part of this amazing pPN.

radio astronomy



systems (metallurgical)


J. F. Desmurs

Observatorio Astronómico Nacional (OAN)

J. Alcolea

Observatorio Astronómico Nacional (OAN)

Michael Lindqvist

Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium

V. Bujarrabal

Observatorio Astronómico Nacional (OAN)

R. Soria-Ruiz

Observatorio Astronómico Nacional (OAN)

P. de Vicente

Observatorio de Yebes (IGN)

Proceedings of Science

18248039 (eISSN)

Vol. 344

14th European VLBI Network Symposium and Users Meeting, EVN 2018
Granada, Spain,


Astronomi, astrofysik och kosmologi


Multidisciplinär geovetenskap

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