[vsnet-alert 8532] Re: SWIFT J1753.5-0127

[Taichi Kato]

Re: SWIFT J1753.5-0127

>     According to ATEL, Swift BAT detected a new gamma-ray source, 
> which may be a new black hole transient.  It has a bright optical 
> counterpart of R~15.8 at 17h53m28.3s, -01d27m06s.

   The Whipple spectrum only shows H-alpha emission (and NaD absorption).
Wouldn't it be rather unusual for an outburst of an X-ray binary?

   What about the distance inferred from the suggested reddening (relatively
low)?  If Lopt(unreddened) is relatively low for a black-hole binary, we may
expect a relatively low inclination (even eclipses?), which might also explain
the lack of high-excitation lines.  (Any other known factors?)

   The observed low-freqeuncy QPOs may be also detected in the optical
(as in XTE J1118+480 = KV UMa).  High-speed photometry would be encouraged.

   Uemura-san's expertise could probably add suggestions and knowledge.