Abstract
We discuss the nature and recent observations (optical and gamma-rays) of symbiotics binary/Mira variable V407 Cygni. In addition we discuss another object of similar category, namely the variable star FY Aql with possible association with an eruptive gamma-ray source.
Highlights
V407 Cyg is a symbiotic binary harboring a Mira variable, of 745 day pulsation and a possible orbital period of 43 years, at a distance of 2.5/3.0 kpc and a reddening of E(B − V ) = 0.5/0.6 (Munari et al 1990)
Other Mira/Symbiotics stars with possible gammaray eruption/association have been known, but without firm confirmation. One of these candidates is the variable star FY Aql located inside the error box of GRB19790331
The investigated Mira/Symbiotics star FY Aql is inside a small error box of the gamma-ray burst (GRB)
Summary
V407 Cyg is a symbiotic binary harboring a Mira variable, of 745 day pulsation and a possible orbital period of 43 years, at a distance of 2.5/3.0 kpc and a reddening of E(B − V ) = 0.5/0.6 (Munari et al 1990) Miras of such a long pulsation period are generally OH/IR sources, with a thick dust envelope which prevents direct observation of the central star. The second group, characterized by much broader profiles for helium, nitrogen and hydrogen lines, originated from the nova fast expanding ejecta. Such a scenario was highly reminiscent of the recurrent nova RS Oph. The outburst of V407 Cyg has since been detected in gamma-rays (ATel 2487) and at radio wavelengths (ATel 2506, ATel 2511, ATel 2514, ATel 2536), and observed in the infrared (CBET 2210 )
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
