VV Cep evolution at low resolution

VV Cep 2017-2019 Campaign
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HughAllen
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Re: VV Cep evolution at low resolution

Post by HughAllen »

Latest update on the progress of the VV Cep eclipse. It looks like the eclipse of the Balmer emission region is fully over. I'll follow the star for another month or two in order to complete the baseline this side of the eclipse. Thanks to all those who allowed me to include their low res spectra in the analysis: Jim Ferreira, James Foster, David Boyd and Steve Cuthbert
Cheers
Hugh
Attachments
VV Cep spectrum 8th June 2019.png
VV Cep spectrum 8th June 2019.png (36.66 KiB) Viewed 8489 times
VV Cep eclipse progress to 8th June 2019.png
Hugh Allen
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Francois Teyssier
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Re: VV Cep evolution at low resolution

Post by Francois Teyssier »

Impressive work and results
Congratulations
François Teyssier
HughAllen
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Re: VV Cep evolution at low resolution

Post by HughAllen »

The British Astronomical Association has published in the August Journal my refereed paper on the spectroscopic evolution of the 2017 - 2019 eclipse of the red supergiant VV Cephei https://britastro.org/journal-full/26122
The BAA does a lot to encourage and support amateur spectroscopy, with mentor schemes, equipment loans and of course the BAA Spectroscopy Database. It's not possible to attach the paper here in pdf format so instead I'm attaching screenshots of each of the 7 pages of the paper if you'd like to read it. Apart from showing how much can be learnt from low resolution spectroscopy, the remarkable result from the study is the changing period in the orbit of the binary star which is quite difficult to explain!
Cheers
Hugh
jbaa_26140_vvcep_eclipse_HughAllen_page1.png
jbaa_26140_vvcep_eclipse_HughAllen_page2.png
jbaa_26140_vvcep_eclipse_HughAllen_page3.png
jbaa_26140_vvcep_eclipse_HughAllen_page4.png
jbaa_26140_vvcep_eclipse_HughAllen_page5.png
jbaa_26140_vvcep_eclipse_HughAllen_page6.png
jbaa_26140_vvcep_eclipse_HughAllen_page7.png
Hugh Allen
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Ernst Pollmann
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Re: VV Cep evolution at low resolution

Post by Ernst Pollmann »

Hi Hugh,
would you be so kind to send me a copy of the paper?
The reference 13 of that paper don`t mentioned the 43 day period of EW and line flux.
The discovery of this periodicity has been published only in the JAAVSO volume 48, 2020.

Ernst Pollmann
HughAllen
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Re: VV Cep evolution at low resolution

Post by HughAllen »

Hi Ernst,
I would be glad to send you a copy but I don't have yur email address. I have emailed you my address through the forum link
Cheers
Hugh

P.S. This is a screenshot of the abstract of your paper in reference 13
Pollmann E IAU Info Bulletin on Variable Stars 63 6249 July 2018 H alpha periodic variation screenshot.png
Hugh Allen
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Ernst Pollmann
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Re: VV Cep evolution at low resolution

Post by Ernst Pollmann »

Hi Hugh,
sorry, you are right. The periodicity of 43 days of EW and line flux has been published in two paper, whereby its character have been described more in detail in the journal of AAVSO.
Here my email address:
ernst-pollmann(et)t-online.de

Ernst
HughAllen
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Re: VV Cep evolution at low resolution

Post by HughAllen »

Hi Ernst,
The email address is not recognised. Please send me a mail at allenhugh10@gmail.com and I will reply
Kind regards
Hugh
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Robin Leadbeater
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Re: VV Cep evolution at low resolution

Post by Robin Leadbeater »

Ernst Pollmann wrote: The periodicity of 43 days of EW and line flux has been published in two paper, whereby its character have been described more in detail in the journal of AAVSO.
Hi Ernst,

Hugh's paper was peer reviewed and accepted for publication before your AAVSO paper was published so had the most up to date reference available at the time

Cheers
Robin
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