87
Model Comparison
€On current knowledge, only strongly ruled out model is the IP, mainly because of lack of photometric evidence for secondary
ˆ
x
x
~
Period decreasing
ˆ
ˆ
ˆ
ˆ
Long-term variability
ˆ
~
~
x
Absence of strong emission lines
ˆ
ˆ
ˆ
x
Absence of H
ˆ
ˆ
~
ˆ
Absence of Polarisation
ˆ
ˆ
ˆ
ˆ
Shape of X-ray modulation
ˆ
~
ˆ
~
Phasing of X-ray and Optical
ˆ
ˆ
ˆ
x
Optical-IR colours
ˆ
ˆ
ˆ
x
Only one modulation period
ˆ
ˆ
ˆ
x
Absence of Hard X-rays
Electric Star (ES)
DD Algol
DD
Polar
IP