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The prototype symbiotic star AX is in outburst

ATel #4265; U. Munari, P. Ochner, S. Dallaporta, A. Milani, P. Valisa, A. Siviero
on 18 Jul 2012; 18:47 UT
Credential Certification: U. Munari (ulisse.munari@oapd.inaf.it)

Subjects: Optical, Cataclysmic Variable, Nova, Variables

The prototype symbiotic stars AX Per is undergoing an outburst, bluer and brighter than the last one it underwent in 2009 (Munari et al. 2009, CBET 1757; Skopal et al. 2011, A&A 536, A27). The following photometric data are representative of the behavior exhibited by AX Per during the last two weeks:

V B-V V-Rc V-Ic
July 08.050 10.322 0.704 0.822 1.969
July 13.023 10.392 0.708 0.879 2.047
July 18.038 10.428 0.725 0.877 2.068


An absolutely calibrated low resolution spectrum of AX Per was obtained on July 18.03 UT with the Asiago 1.22m telescope of the University of Padova, Dept. of Physics and Astronomy. An Echelle spectrum of AX Per was obtained on with the Multi-Mode Spectrograph mounted on July 18.11 the 0.60-m UT telescope of the Schiaparelli Observatory in Varese. The spectra are characterized by a strong blue continuum with the TiO bands of the cool giant that become visible only longword of 4800 Ang. The Balmer continuum is in strong emission. The emission lines are dominated by hydrogen Balmer and HeI. The Hbeta line is 3.3 times stronger than HeII 4686. Representative integrated absolute fluxes of emission lines are (units of 10[-12] erg cm-2 sec-1): 55.4 for Halpha, 11.0 for Hbeta, 4.34 for Hgamma, 1.25 for [OIII] 4363, 3.39 for [OIII] 5007, 2.37 for HeI 5876, 2.22 for HeI 6678, 3.21 for HeII 4686, 1.46 for [NeIII] 3869. The line profiles are Gaussian-like, with no P-Cyg absorption components, and are sharp. They average FWHM for HeI lines is 75 km/sec, for Balmer lines 105 km/s, and for HeII 125 km/sec. No trace of bipolar jet emission is discernible on the wings of Balmer lines.