Observation state of the campaign

VV Cep 2017-2019 Campaign
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Re: Observation state of the campaign

Postby Ernst Pollmann » Fri Jan 12, 2018 5:29 pm

Dear colleagues,
Here a summery of the Halpha behavior since Nov. 2017.

If we take as scale the sum EW of the red and blue component of the last eclipse 1997 (Fig. right above), then we might say that the accretion disk is at present still not complete eclipsed. But this would be applicable only, if the size of the disk is the same then in the past.

Within this campaign I had suggested, to try the determination of the disk diameter, based on the time difference of the eclipse between the blue to the red emission.

The start of the eclipse of the blue emission is clearly to detect at around JD 2457900 (end of May 2017) followed by a steep decrease of the intensity. This is better to recognize in the peak height plot (Fig. left above) than in the EW plot (Fig. left bottom).

The determination of the beginning of red emission eclipse however is still very difficult as long as we can not clear recognize its indubitable intensity decrease. This difficulty is linked with the strong periodicity (~ 43 days) we found among others in the ratio V/R (Fig. right bottom).

This periodicity is still one of our very special observation results. If we can observe it also during the phase of the total eclipse and of course also afterwards, then we can be very sure to have detected for a first time a precession phenomenon of the B star accretion disk. A more comprehensive intermediate report written by Phil Bennett and me will be published during the next weeks at this forum.
vvcep_Jan-2018.jpg (81.34 KiB) Viewed 132 times

Ernst Pollmann
Ernst Pollmann
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Re: Observation state of the campaign

Postby Olivier GARDE » Wed Jan 24, 2018 3:47 pm

My last spectrum of VV Cep taken last night with eShel spectrograph R=11000 with bad weather conditions (clouds and fog)

LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
Olivier GARDE
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Location: Rhône Alpes FRANCE


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