Letter to the Editor

Discovery of the first Ca-bearing molecule in space: CaNC^⋆

¹ Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
e-mail: jose.cernicharo@csic.es
² Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
³ Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 Saint Martin d’Hères, France

Received: 6 June 2019
Accepted: 14 June 2019

Abstract

We report on the detection of calcium isocyanide, CaNC, in the carbon-rich evolved star IRC+10216. We derived a column density for this species of (2 ± 0.5) × 10¹¹ cm⁻². Based on the observed line profiles and the modelling of its emission through the envelope, the molecule has to be produced in the intermediate and outer layers of the circumstellar envelope where other metal-isocyanides have previously been found in this source. The abundance ratio of CaNC relative to MgNC and FeCN is ≃1/60 and ≃1, respectively. We searched for the species CaF, CaCl, CaC, CaCCH, and CaCH₃ for which accurate frequency predictions are available. Only upper limits have been obtained for these molecules.