[AAVSO LightCurve, 1yr]
[AAVSO LightCurve, 5yr]
GCVS data:
Epoch 2000: ra = 254.458, dec = 35.342
Variability type: XPR+E
Spectral type: B0Ve-F5e
GCVS remarks:
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; the source is faint during 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; the star was still 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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Chart status: OK