EE Cephei

EE CEPHEI

EE Cephei (Cep)

EE Cep is an eclipsing binary whose nature still remains unclear. The various features observed during the different eclipses and the lack of any evidence for a star-like secondary are in favour with the hypothesis that the secondary contains a dark, opaque disc covering a central low-luminosity star or binary system.

The most promising model remains that of a dark, precessing disk around a low luminosity central object (Mikolajewski & Graczyk 1999, Graczyk et al. 2003). The precession changes both the inclination of the disc to the line of sight, and the tilt of its cross-section to the transit direction. The unique shape of the eclipse observed in 1969 can be explained by a practically edge-on and non-tilted projection of the disc. Two hypotheses can be considered for such a disc: (i) it has a proto-planetary origin; (ii) it is a post-planetary object (a result of planetary disintegration). An important question is the nature of the central body embedded in the disk. It can be a low massive single star or a close binary system. The only similar object previously known with a dark circumstellar disc is epsilon Aur - the longest period (~27 years) eclipsing binary.

Comparison Stars

EE CEPHEI DATA

EE Cephei = HR = HD
Name: ?

R.A. (2000) 22h 09m 22.771s
DEC. (2000) +55d 45' 24.76"

COMP
A

B

SPECT.
B5III-IV+e

B8 Ve

DIAM
?

MASS
?

?

LUM.
?

?

ABS.
?

?

MAG
?

?

TEMP.
?

?

I

xx

V - I
+3.04

R

xx

R - I
+1.40

V

10.72/12.15

B - V
+1.77

B

xx

U - B
+0.39

U

xx