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Re: VV Cep evolution at low resolution

Posted: Sun Jun 09, 2019 11:59 am
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

Re: VV Cep evolution at low resolution

Posted: Sun Jun 09, 2019 3:54 pm
by Francois Teyssier
Impressive work and results
Congratulations
François Teyssier

Re: VV Cep evolution at low resolution

Posted: Sun Sep 05, 2021 9:49 pm
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

Re: VV Cep evolution at low resolution

Posted: Thu Sep 09, 2021 12:48 pm
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

Re: VV Cep evolution at low resolution

Posted: Thu Sep 09, 2021 7:36 pm
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

Re: VV Cep evolution at low resolution

Posted: Fri Sep 10, 2021 1:47 pm
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

Re: VV Cep evolution at low resolution

Posted: Sat Sep 11, 2021 12:24 am
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

Re: VV Cep evolution at low resolution

Posted: Sat Sep 11, 2021 2:38 pm
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