Many times over the past decade, WR 140 has been a target for long-term multiwavelength campaigns with subsequent state-of-the-art modeling of the colliding-wind phenomenon. In 1999–2002 we intensified our large optical campaign in an attempt to follow the system with shorter time steps through the 2001 periastron passage. To our surprise, the ‘‘ clockwork ’’ behavior ofWR 140 changed dramatically during its periastron passage in 2001. (from Marchenko et al. 2003, The Astrophysical Journal, 596, 1295)

Major parameters of WR 140

• Type: WR+O binary

• Visual Magnitude = 7.07 mag

• Periastron passage at = HJD 2446147.4 ± 3.7 (1985)

• Period P = 2899.0 ± 1.3

• Inclination i = 50° +/- 15°

• Half openning angle of the shock cone q = 40° +/- 15°

• Excentricity e = 0.881 +/- 0.005

• Coordinates RA (2000) 20h 20' 28'', DEC (2000) +43° 51' 16''

Next passage at HJD = 2454844 or January 12, 2009

More information in Literature and from Thomas Eversberg. See also subsequent discussions in our Forum.