VV Cep stars
VV Cephei (HD208816) is the principal
star of a class of massive eclipsing binary consisting of an M supergiant
and a hot B type companion. Its optical spectrum is characterized
by strong Balmer and [Fe II] emission line. The spectrum is of very
complex type: M2Ia-Iabep + B8:Ve (composite spectra, with a very
cool star and a hot star together). A mass transfer exist between
the two components. For VV Cephei, the orbital period is 7430 days
(20.3 years). The date of the mid-point of the last eclipse is January
4, 1998. At the time of eclipse the H-alpha emission disappear progressively.
The total duration of the eclipse is about 1100 - 1400 days. VV
Cep is also a semi-regular long-period variable (magnitude = 4.8
- 5.4). For more info, click here. Other members of VV Cep class:
KN Cas, AZ Cas, KP Pup, W Cep, U Lac, Alpha Sco.
of VV Cephei
VV Cep localisation:
VV Cep = HD 208816 R.A.(2000)
= 21 h 56 m 39s Dec.(2000) =
63° 37' 32"
Comparison of the 22/08/1999
and 10/09/1999 spectra of VV Cep. Note the good correlation
between this two spectra. The 10/09/1999 is artificialy translated
verticaly of 0.2. The spectrum is very complex.
H-alpha profile of VV Cep.
of Alpha Scorpii
A semi-regular pulsating star. Type M1.5Ib.
Position (J2000): R.A. = 16 h 29 m 24 s Dec.
= -26° 25' 55"