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Her X-1 = 4U 1656 + 35. Lx/Lopt = 2 - 60.
The Table gives elements for light minima due
to eclipsing variability and the reflection effect. Min I
coincides with the X-ray eclipse. Shallow Min II may
be present. The reflection effect causes variations
with Delta(m) up to 1.5m. A cycle of 34.875d duration is
"observed in X-ray band
two thirds of the cycle. The optical light curve changes
are observed during the 35d cycle [09283]. According to
[06539], during JD2427543 - 657 and JD2428630 - 29789 the
"strong reflection effect was absent
varying with P = 1.7d and had Delta(m) ~0.5m,
Min I = Min II. In [06546] it is stated that
such intervals with no reflection effect, of 8d to 7a
duration, took place for almost half the time since
1890. The light changes during such intervals are in
the range 14.7m - 15.2m pg. Since 1957 intervals without
the reflection effect were not observed. In June - July
1983 the predicted phases of high X-ray flux
did not take place, but the reflection effect did not
disappear [09284]. Secondary light variations: P1 =
1.0977d (delta(B1) = 0.33m), P2 = 0.871173d*E
(delta(B2) = 0.10m),
P3 = 1.623846d*E (delta(B3) = 0.17m) [09285]. X-ray pulsar,
P = 1.2377991s (JD2443357), dP/dt/P = (-2.9 +- 0.2)*10**(-6)/yr
[09286], sometimes noticeable also in the
optical range [06543]. Rapid brightness flickering.
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