BU Tauri
Up to October 27, 2009
Including ASAS-3 and Doug West V data
BU Tau (Pleione)
is rising slowly after the faint state during its latest Be-shell
phase.
The visual magnitude of the star got as faint as V= 5.4 from September 2006 to
at least March 2009,
0.4 mag. fainter than its normal state.
Previous Be-shell phases started in 1938 and 1972 which means there is a
remarkable periodicity in Pleione's changes.
This is consistent with the star being a binary system with a 34-35 year orbital
period as suggested in Luthardt and Menchenkova (1994).
According to ASAS data it was around V= 5.28 on October 27, 2009.
References:
Katahira, J., et al., 2006, The Be Star Newsletter, Vol. 38(http://astsun.astro.virginia.edu/~dam3ma/benews/volume38/whap/kat0.html)
Luthardt, R. & Menchenkova, E. V, 1994, A&A, 284, 118. (http://articlesadsabs.harvard.edu/cgi-bin/nph-iarticle_query?1994A&A...284..118L)