[vsnet-chat 944] Re: Expected SN Ia maximum in M96

[Taichi Kato <tkato>]

>   Instead, we should use the distance estimated by
> other method (T-F relation, Cepheid, and so on) and compare it with
> the Virgo distance derived by HST (16 - 17 Mpc).  For M96 case, the
> catalogued distance was 8.1 Mpc (Turry, Nearby Galaxy Catalog), which
> implies that a object in M96 will be seen brighter about 1.6 mag than
> it were in Virgo.

   I presume the difference in distance modulus has been (regardless of the
H_0 value) determined between Leo group and the Virgo.  I remember Leo
group was chosen as one of the first groups beyond the M81 group for a target
of several recently developed techniques (PN luminosity function, surface
brightness fluctuation etc.).  Am I right?  And isn't Cepheid-based distance
modulus for such a nearby group available?

> It seems not a good assumption; first, the difference in magnitude
> between the different band, i.e., the color of SN is changing day by
> day.

   It seems the J-K color of typical type Ia SNe is near zero around
maximum (cf. the classical work of Elias et al. 1981, Ap. J. 251, L15).
If V-J is also near zero at maximum, the K color may provide an unreddened
measure of V.

Regards,
Taichi Kato

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