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

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. 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.

IPHAS and the symbiotic stars

“…Reduction of all spectra was carried out with standard routines in IRAF V2.16 1 . In addition, a spectrum of the symbiotic star IPHASJ190832.31+051226.6 (discovered in Corradi et al 2010b) was obtained with the same telescope and configuration as above.…”

“…We also present the monitoring of IPHASJ190832.31+051226.6 3 , whose discovery was presented in Corradi et al (2010b) based on spectra obtained in 2006 and 2009. In the latter, the source was almost ten times brighter than in the former, the continuum turned bluer, Corradi et al (2010b) used model fit to the optical spectrum to determine a spectral type for the giant between M4.0 III and M6.0 III with A V = 4.8 and 5.2 mag, respectively.…”

“…We also present the monitoring of IPHASJ190832.31+051226.6 3 , whose discovery was presented in Corradi et al (2010b) based on spectra obtained in 2006 and 2009. In the latter, the source was almost ten times brighter than in the former, the continuum turned bluer, Corradi et al (2010b) used model fit to the optical spectrum to determine a spectral type for the giant between M4.0 III and M6.0 III with A V = 4.8 and 5.2 mag, respectively. As in previous objects, we have fitted reddened photospheres to the SED of IPHASJ190832.31+051226.6 finding that a M6.0 III star with A V = 6 mag provides the best fit in the range of possible types from Corradi et al (2010b).…”

“…In the latter, the source was almost ten times brighter than in the former, the continuum turned bluer, Corradi et al (2010b) used model fit to the optical spectrum to determine a spectral type for the giant between M4.0 III and M6.0 III with A V = 4.8 and 5.2 mag, respectively. As in previous objects, we have fitted reddened photospheres to the SED of IPHASJ190832.31+051226.6 finding that a M6.0 III star with A V = 6 mag provides the best fit in the range of possible types from Corradi et al (2010b). For the distance of 5.4 kpc quoted by those authors, a luminosity of 1070 L is obtained, in good agreement with the value expected for an M6 III star.…”

“…The description of the A&A 567, A49 (2014) photometric method adopted to select symbiotic star candidates was presented by Corradi et al (2008Corradi et al ( , 2010a, hereafter Papers I and II. Along with individual studies of other outstanding objects (Corradi & Giammanco 2010;Corradi et al 2010bCorradi et al , 2011, IPHAS and follow-up spectroscopy allowed us to discover fourteen new symbiotic stars in the 1800 square-degree IPHAS area (covering Galactic latitudes between −5 • and +5 • in the northern sky), where previously only eleven symbiotic stars were known. In these articles, we also emphasized the need for robust selection criteria to distinguish symbiotic stars from the most problematic mimics, and in particular from T Tauri stars and other young stellar objects (YSOs) that are much more frequent than symbiotic stars in the Galactic plane.…”