Last news of FF cam before poster publication at HVAR2012

Anatoly Miroshnichenko and Stephen Danford, from University of North Carolina in Greensboro have begun to analyze the large collection of data on FF cam, available in Bess database.

"Dear colleagues,

Let me congratulate you on a discovery of binarity of FFCam. Thierry's
initial suggestion from a dynamic spectrum is confirmed by
measurements of the radial velocity of the Ca I 6102.72 A line that
belong to the cool component of the system. The orbital period is
7.785 days. I have only measured one line. Its equivalent width is
almost unchanged during the orbital cycle. It probably means that the
system is not eclipsing. Next step is to try to measure radial
velocity of emission lines in order to find the component mass ratio.
I'll do that very soon. A figure of the radial velocity variations is
attached. I have used 32 spectra obtained by Stephane and Thierry."

The system is described as a symbiotic star! A hot dwarf star is in connection with a cool one. The cool component seems to fill its Roche lobe and pour the material into the hot star Roche lobe. So, the system seems to be a semi-detached binary with an accretion disk, not a typical decretion Be disk

It looks like the mass transfer is unstable. This results in a wave-like behavior of the H-alpha EW. A short-term increase/outburst of the mass transfer leads to a EW increase, then mass either gets
accreted or lost from the system (or both) and EW decreases, then the process repeats again. This is seen at the plot of H alpha EW versus time.

About the HVAR2012 poster

The updated reference to it is: Garrel, T., Miroshnichenko, A., Danforf, S., Charbonnel, S., Houpert, F., Grankin, K.N., & Kusakin, A.V. "Spectroscopy of the mysterious Be system FF Cam", poster at the
XI-th Hvar Astrophysical Colloquium "The Most Mysterious Binaries: Significance for Astrophysics", 2012 July 2-6.
The last two authors supply multicolor photometry. Konstantin Grankin obtained two UBVRI observations on 2012 April 13 and 15 in Crimea, while Anatoly Kusakin got a few BVR data in April and May in
Kazakhstan. Stephane Charbonel and Franck Houpert acquired spectra of FF cam.

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Comments

[John]

Thats great news that FFCAM has been recognised as a symbiotic star. Can't wait to see the poster.



cheers



John