Letter to the Editor

The ongoing outburst of the new symbiotic star IPHASJ190832.31+051226.6^*

R. L. M. Corradi^1,2, U. Munari³, R. Greimel⁴, M. M. Rubio-Díez⁵, M. Santander-García^5,1,2, P. Rodríguez-Gil^5,1,2, J. E. Drew⁶, P. Leisy⁵, T. Liimets^7,8 and S. E. Sale⁹

¹ Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain e-mail: rcorradi@iac.es
² Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain
³ INAF, Osservatorio Astronomico di Padova, via dell'Osservatorio 8, 36012 Asiago (VI), Italy
⁴ Institut für Physik, Karl-Franzen Universität Graz, Universitätsplatz 5, 8010 Graz, Austria
⁵ Isaac Newton Group of Telescopes, Apart. de Correos 321, 38700 Santa Cruz de la Palma, Spain
⁶ Centre for Astrophysics Research, STRI, University of Hertfordshire, College Lane, Hatfield, AL10 9AB, UK
⁷ Nordic Optical Telescope, Apart. de Correos 474, 38700 Santa Cruz de la Palma, Spain
⁸ Tartu Observatoorium, Tõravere 61602, Estonia
⁹ Astrophysics Group, Imperial College of Science, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, UK

Received: 12 November 2009
Accepted: 22 December 2009

Abstract

Aims. Eleven new symbiotic stars have recently been discovered with IPHAS, the INT Hα survey of the Northern Galactic plane. The star IPHAS J190832.31+051226.6 was proposed as an additional candidate on the basis of the existing spectrum. Here, we investigate the nature of this source by means of additional observations.

Methods. Photometric data, optical spectra obtained in 2006 and 2009, a higher resolution spectrum resolving the Hα profile, and near-IR spectra of IPHAS J190832.31+051226.6 are all presented.

Results. The source brightened in the r band by 2.3 mag from 2004 to 2009. From 2006 to 2009, the spectrum has evolved from one with the obvious continuum of an M giant star plus HI and HeI lines in emission to a lower excitation nebular spectrum with HI, CaII, and FeII emission and a bluer continuum in which the absorption bands of the red giant are only visible at wavelengths longer than 7500 Å. The Hα line is broad with a deep central absorption and extended wings.

Conclusions. The averaged rate of the brightness increase, the rise of a blue continuum overwhelming the absorption bands of the M giant, and the corresponding decline of the ionization condition of the emission-line spectrum, are all consistent with the hypothesis that IPHAS J190832.31+051226.6 is a new symbiotic star picked up during the onset of a symbiotic nova outburst that is still in progress at the time of writing.