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 07m 34.7s
DEC. (2000) +55d 30' 39"

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

Distance: ? light years

Epoch: JD 2,434,346.0

Period: 2049.53 days/ 5.6 years

Secondary Eclipse at Phase: ?

Ingress/Egress: ? days
Totality: ? days

Next Eclipse: (?)

Secondary Eclipse - ?

Maximum Separation Date - ?

References

IBVS 965

IBVS 1225

IBVS 1939

IBVS 5412

EE Cep 2003 (pdf 160 K)

Is the eclipsing variable EE Cep
a cousin of epsilon Aur?