[vsnet-chat 3772] WX Hyi behaviour

["Berto Monard" <LAGMonar@csir.co.za>]

Hi Stan,

 

thanks for asking..

My point was that there was no time delay of more than a couple of hours between the last s/outburst and the next normal outburst (or whatever looked like it). A s/outburst is usually seen as a cleanout phase of the accretion disk and therefore one would expect some time delay to built up a new accretion flow before the next (normal) outburst.

BTW the nova phenomenon relates to the 'clean-out' on the WD surface, not the accretion disk.

 

The fact that the s/outburst took place immediately after the previous normal outburst is not unique and seems to occur more often incl in other systems.

 

I cannot reply on Taichi's behalf..

 

Regards,

 

Berto

 

>>> "Stan Walker" <astroman@voyager.co.nz> 11/15/00 09:08PM >>>

Hi Berto,

 

I noticed your question and TK's reply. But both of you know what the dates and durations were - the rest of us don't. So I'm not sure what TK is really saying, or what you're asking. Could you elaborate a little?  I think the interval you should be considering is between successive normal outbursts - the superoutburst is a completely different event which - from an observational viewpoint - doesn't affect the normal outbursts much. There seems to be a shortening of the cycle and a reduction in amplitude, but this is not as evident in the systems with fewer normal outbursts.

 

What is this 'complete cleaning' phase you mention involving hydrogen? This seems more of a nova phenomenon.

 

Regards,

Stan 

----- Original Message -----

From: Berto Monard

To: vsnet-chat@kusastro.kyoto-u.ac.jp

Sent: Wednesday, November 15, 2000 7:15 PM

Subject: [vsnet-chat 3767] WX Hyi behaviour

Hi,

 

WX Hyi has just shown the following sequence of events in succession

 

1. normal outburst

2. superoutburst

3. another normal (?) outburst, ongoing at this moment.

 

Phases 1 and 2 do occur in succession with other systems too.

However event 3 seems a bit out of phase. The going theory spells that the superoutburst is the 'complete cleaning' phase, iow all H is burned away.

What happens to WX Hyi then for it still to have another outburst? Is it unstable mass transfer by the secondary triggered by the past s/outburst or is it due to another unrelated activity?

 

Do I hear 'flickering'?

 

Regards,

 

Berto Monard

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