BF Cyg

[Tim Lester]

BF Cyg around H alpha for 2015-04-01 (AAVSO Vmag 9.5)
I had excellent transparency and seeing so I calibrated to flux (based on the Cflib reference star HD182568 - Vmag 5.00).
The expanded plot shows a comparison with my last low res spectrum from 2014-06-16 also calibrated for flux by using a Vmag of 10.6 (from AAVSO)
An interesting shape for H alpha.
It would appear that the although there has been a full magnitude of brightening the total intensity in the H alpha line has actually decreased.
I don't know if this makes any sense.

_bfcyg_flux_Ha.png (6.69 KiB) Viewed 2686 times

Tim

[Francois Teyssier]

Very interesting.
The peculiar shape of Balmer lines at this stage will be in the information letter, to be published today.
According to A. Skopal, the large hump in the red part of the line is a staellite emission produced by a collimated ejection
See : http://www.aanda.org/articles/aa/abs/20 ... 30-13.html
All the best,
François