[vsnet-chat 340] Re: any black-hole transient candidates?

[Erik Kuulkers <e.kuulkers1@physics.oxford.ac.uk>]

Taichi Kato wote:
> Are there any potential black-hole transient progenitors?  

The only obvious potential black-hole transient progenitors are those which 
have been shown outbursts before, such as V616 Mon (Nova Mon 1975) and
V404 Cyg (Nova Cyg 1989). V616 Mon has had an outburst in 1917 and 1975
suggesting a recurrence time of ~58 years, while V404 Cyg showed outbursts 
in 1938 and 1989. 

> Is there a way to find such objects in dormancy?  

Such objects are very faint in quiescence (V~18 mag for V616 Mon, while
typically fainter than 19-20 mag for others), and are therefore very 
difficult to find. 

> Is V616 Mon considered to be the nearest such object?

Yes, V616 Mon is estimated to be "only" 900 pc away.

Regards,

Erik Kuulkers

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp