[vsnet-chat 2276] (fwd) Re: Strong oscillation in Nova Cir1999?

[Berto Monard <lagmonar@csir.co.za>]

Dear Taichi and readers,

I would like to comment on the posting from Brian Fraser. 

There is a definite possibility of magnitude estimate off-sets due to
personal differences in red/blue sensitivity and perhaps here and
there some personal bias regarding to what possibly is the expected
magnitude of the nova at that moment. 
However I disagree that this should be generalised and that I
therefore wish to state my agreement with Taichi's statement that the
oscillations are a true representation of the nova's past behaviour. I
have no doubt that the nova has been down to (at least) around
magnitude 8.7 on 24/8 (as reported by experienced observers) and that
it re-brightened afterwards and reported 12 hours later at around 8.0
by experienced observers from other continents. This oscillation has
repeated itself with a diminishing amplitude during the following 24 h
as seen in the lightcurve by experienced observers. 
There is no doubt in my mind that a (probably aperiodic) oscillation
in the luminosity of Nova Cir 1999 took place.

Best regards,

Berto Monard
Pretoria

>>> Taichi Kato <tkato@kusastro.kyoto-u.ac.jp> 09/02 10:40 AM >>>
From brian.fraser@Macsteel.co.za Thu Sep  2 15:25 JST 1999
From: "brian.fraser" <brian.fraser@Macsteel.co.za>
To: Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>
Subject: RE: [vsnet-chat 2273] Strong oscillation in Nova Cir 1999?
Date: Thu, 2 Sep 1999 08:14:47 +0200 
MIME-Version: 1.0
Content-Type: text/plain
Content-Length: 1428

Hello Taichi,
I was thinking about  this topic when I came upon this possible
explanation.
It looks to me as though each observer has his "personal bias" ie when
he is
in doubt he goes for a lower estimate or maybe a higher estimate.
So you are looking at the results from one or two observers in
Australia,
one or two in South America, some in South Africa.  If an active
observer in
Australia is consistently over-estimating the magnitude (just by 0.1
or 0.2)
and an observer in South Africa is consistently under-estimating, it
could
quite easily look as though there was a one day cycle.  Maybe this is
what
is happening??
Just a thought,
regards,
Brian Fraser

=======================================================
Trust in God but lock your car.

Brian Fraser
Tel 27 11 871-0370
Fax 27 11 871-0226
email brian.fraser@macsteel.co.za 


> -----Original Message-----
> From: Taichi Kato [SMTP:tkato@kusastro.kyoto-u.ac.jp] 
> Sent: Wednesday, September 01, 1999 4:41 PM
> To: vsnet-chat@kusastro.kyoto-u.ac.jp 
> Subject: [vsnet-chat 2273] Strong oscillation in Nova Cir 1999?
> 
> Strong oscillation in Nova Cir 1999?
> 
>    Upon examination of the reported data, I have noticed the nova
may be
> oscillating with a period close to 1 d.  On Aug. 24 and 25, the nova
> faded by nearly 1 mag within 12 hours, and recovered (not well
covered
> by observations).  Has anyone noticed this phenomenon?
> 
> Regards,
> Taichi Kato

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