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AZ Cas 3760-4120A changes during ingress

Posted: Mon Dec 03, 2012 12:50 pm
by Robin Leadbeater
The spectrum in the region 3760-4120A show some large and rapid changes during ingress. Unfortunately these are almost impossible for me to record now the brightness has dropped (The last spectrum is 10 hours exposure over 2 nights :o ) Cezary also has problems recording in this region (See note from him below) so although not very good, my spectra may be unique. Is anyone else able to record in the region, for example using a LISA and a camera with better blue sensitivity?

Cheers
Robin


----- Original Message -----
From: <Cezary.Galan@astri.uni.torun.pl>
To: "Robin Leadbeater"
Sent: Monday, December 03, 2012 9:48 AM
Subject: Re: AZCas eclipse - near to the ingress

>
> Hi Robin,
>
> Thank you for this figure. Your spectra, although not of the highest
> quality, they are very valuable as perhaps nobody else was doing
> spectroscopic observations in violet. We did not have here in Piwnice good
> enough weather to take such a spectra and we were able only get
> photometric measurements for 2 nights during ingress. Our technical staff
> still can not cope with the axes of our old (~60 yrs) Schmidt-Cassegrain
> telescope. In result we have terrible comma and very weak signal in blue
> (Although the telskop is quite large (90 cm primary mirror) it gives an
> embarrassingly poor results especially in blue range). We hope to deal
> with this and in addition to organize somewhat more instruments to collect
> spectroscopic observations in violet around egress and after it, during
> atmospheric eclipse. We have still chance to document better with spectra
> in violet, the passage of the B star behind of the dense envelope of
> matter escaping from the supergiant, during the final phase of the
> eclipse.
>
> Cheers
> Cezary

Re: AZ Cas 3760-4120A changes during ingress

Posted: Mon Dec 03, 2012 8:24 pm
by Christian Buil
Robin you are a brave man!
The object is so faint in the blue region....
The result is spectacular.

Personnaly, I concentrate my effort on Halpha line (perhaps an error?).
Clearly LISA can capture the AZ Cas blue features with high efficiency. But, for me, the weather is not
very favorable for change quicky the spectrograph at the focus of the telescope during the same night.

I encourage all LISA users to monitor AZ Cas !

Christian