Low spectra of CH Cyg and BF Cyg required
Posted: Wed Apr 15, 2015 5:55 pm
In these two stars appears fast and dramatic evolutions of line profiles
See for example
Comment from Augustin Skopal :
I have looked the new spectra of CH Cyg and BF Cyg. Really dramatic
changes in the profiles of Balmer lines on the time-scale of a few days!
Also on BF Cyg
Comment from Augustin Skopal :
As concerns to BF Cyg, I was also surprised with changes in the hydrogen
line profiles. At first look the shift to the red seems as a result
of a wrong calibration of the last spectrum from 12/04/2015, but
comparing the 01/04/2015 spectrum to that from 23/03/2015 suggests
that calibration and/or heliocentric correction is O.K. Just significantly
more absorption on the blue side, and more emission on the red side of
the line appeared.
A. Skopal's request :
However, to interpret such variations will not an easy task. Above all,
we need the continuum profile, which is possible to obtain by modelling
the low-resolution spectra. So, I hope that somebody will obtain also
a low-res spectrum (CH Cyg and BF Cyg).
Waiting for spectra,
François Teyssier
See for example
Comment from Augustin Skopal :
I have looked the new spectra of CH Cyg and BF Cyg. Really dramatic
changes in the profiles of Balmer lines on the time-scale of a few days!
Also on BF Cyg
Comment from Augustin Skopal :
As concerns to BF Cyg, I was also surprised with changes in the hydrogen
line profiles. At first look the shift to the red seems as a result
of a wrong calibration of the last spectrum from 12/04/2015, but
comparing the 01/04/2015 spectrum to that from 23/03/2015 suggests
that calibration and/or heliocentric correction is O.K. Just significantly
more absorption on the blue side, and more emission on the red side of
the line appeared.
A. Skopal's request :
However, to interpret such variations will not an easy task. Above all,
we need the continuum profile, which is possible to obtain by modelling
the low-resolution spectra. So, I hope that somebody will obtain also
a low-res spectrum (CH Cyg and BF Cyg).
Waiting for spectra,
François Teyssier