[IAUC] CBET 1885: 20090727 : EPSILON AURIGAE

[IAUC mailing list]

                                                  Electronic Telegram No. 1885
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS en CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT en CFA.HARVARD.EDU (science)
URL http://www.cfa.harvard.edu/iau/cbat.html


EPSILON AURIGAE
     E. O. Waagen, AAVSO, writes that R. Leadbeater, Wigton, U.K., reported
(via the AAVSO Discussion Group) the spectroscopic detection of the start of
a predicted eclipse for the long-period binary star epsilon Aur.  The last
eclipse was in 1982-1984.  A redshifted component in the K I 769.9-nm line
has appeared in LHIRES III observations obtained on July 20.081 UT, offset by
+15 km/s and with 62-mA equivalent width.  This emerging feature is uniquely
associated with eclipse phases, wherein visual light declines by 0.75 mag
over 18 months.  Information on the international epsilon Aur eclipse
campaign may be found at website URL http://www.citizensky.org.  Selected
visual magnitude estimates submitted to the AAVSO International Database:
Apr. 28.818 UT, 2.9 (M. Rzepka, Krosno, Poland); May 23.233, 2.9 (P. Abbott,
Leduc, Alberta, Canada); June 21.924, 2.9 (V. Makela, Helsinki, Finland);
July 3.078, 2.9 (S. Baroni, Milan, Italy); 22.035, 3.0 (P. Maurer, Bad
Friedichshall, Germany).  H and J magnitudes submitted to the AAVSO
International Database:  Apr. 24.022, J = 1.77 (B. McCandless, Elkton, MD,
U.S.A.); 24.043, H = 1.50 (McCandless); May 13.053, J = 1.83 (T. Rutherford,
Blountville, TN, U.S.A.); 13.065, H = 1.53 (McCandless); 30.06, J = 1.85,
H = 1.61 (Rutherford).  BVRI magnitudes submitted to the AAVSO International
Database:  Apr. 24.07, V = 2.92, R = 2.51 (McCandless); 24.078, B = 3.45
(G. Samolyk, Greenfield, WI, U.S.A.); May 13.055, R = 2.38 (McCandless);
July 3.961, V = 2.87, I_c = 2.21 (R. Miles, Stourton Caundle, Dorset,
England); 20.026, I_c = 2.33 (Miles); 20.044, V = 3.03 (Miles).


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2009 CBAT
2009 July 27                     (CBET 1885)              Daniel W. E. Green