Return to Home Page
Re: Nova V2540 Oph getting "bluer"? > On 08/19/2002 V-Rc=0.85 and currently V-Rc=0.67. V2540 Oph is getting > "bluer", I'm not sure what that means in terms of nova development. Maybe it > has entered the nebular phase? Possibly there is less dust surrounding the > nova and hence less reddening? I'm open to suggestions. It would be likely that the contribution from Halpha emssion line has reduced (the line can contribute to ~1.0 mag in Rc band for usual classical novae). This possibility could be easily tested by measuring a spectrum (measure equivalent width). It may be also possible different lines started more contributing to the V-band. In either cases, interpretation of broad-band colors of novae requires special attention. If one would use an intermediate-band filter such as Stoemgren y instead of V, and Ic instead of Rc (Ic contains less strong emission lines), the continuum color would be easier to assess. Regards, Taichi Kato
Return to the Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
