[vsnet-alert 5591] RE: [vsnet-campaign 705] V344 Ori data from Vanmunster, and some more

["Tonny Vanmunster" <Tonny.Vanmunster@advalvas.be>]

Dear Taichi and others,

This kind of 1-hour scale, large amplitude modulations and irregularities,
and the corresponding ~0.12d periodicity are indeed not very frequently
observed in erupting dwarf novae, as far as I know and can deduce from my
CCD observations over the past 5 years. There's one very similar case
however, call it a 'twin' of V344 Ori, that comes to my mind, and that's
V405 Vul (S 10943). During the August 2000 outburst of V405 Vul, I followed
this object very intensively through CCD photometry, together with some
colleagues from other CBA stations (Bob Fried, Sergey Shugarov) for over 2
weeks. We got dense coverage and Sergey and I have been making various
attempts to analyse the periodicities in this system, finding also values
around 0.12d - 0.14d. However, we never got secure, stable values over the
entire observing period.

I think it would be worthwhile to give some priority to both objects in
terms of next outburst coverage. Moreover, they are an ideal 'couple', as
one is primarily a Summer target and the other a Winter target.

Best regards,
Tonny

> -----Original Message-----
> From: owner-vsnet-campaign@kusastro.kyoto-u.ac.jp
> [mailto:owner-vsnet-campaign@kusastro.kyoto-u.ac.jp]On Behalf Of Taichi
> Kato
> Sent: Saturday 20 January 2001 10:14 AM
> To: vsnet-alert@kusastro.kyoto-u.ac.jp;
> vsnet-campaign@kusastro.kyoto-u.ac.jp
> Subject: [vsnet-campaign 705] V344 Ori data from Vanmunster, and some
> more
>
>
> V344 Ori data from Vanmunster, and some more
>
> Dear Colleagues,
>
>     We have received the data on Jan. 16 from Vanumunster.  A preliminary
> look at the data seems to confirm the finding in [vsnet-alert 5586]
> and [vsnet-campaign 704].  The entire data set, together with the Kyoto
> new data, will be intensively analyzed by Uemura-san.  There seems to be
> an (short) underlying periodicity, as reported by Uemura-san, together
> with irregularities.  Such a kind of a 1-hour scale, large-amplitude
> modulations during outburst (esp. bright) of dwarf novae are infrequently
> seen.  We therefore encourage observers to continue intensively covering
> the present rare, bright outburst.  We would be extremely happy to be keep
> informed of the progress of observations.
>
> Regards,
> VSNET Collaboration team
>
>

VSNET Home Page

Return to Daisaku Nogami

---

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