Abstract
EXTENDED Ariel V observations in September and December 1977 centred on 4U1145–61 reveal two X-ray periodicities at 4.95 and 4.86 min. The amplitude of both varied, the former by a factor 2, the latter by a factor 7. The shorter period decreased by 0.0015 min over an interval of 50 d while the longer increased by 0.0034 min in the same period. Measurements of the pulse phase revealed no evidence for orbital motion and upper limits to ax sin i are given. It is not possible to determine whether these modulations both originate from 4U1145–61 or if there is an unreported source within 1° of 4U1145–61. The X-ray spectrum was unusual with a break at ∼9 keV. We have obtained spectra of the optical counterpart, HEN715, at 25 Å mm−1 resolution in the range 3,700–5,300 Å and 6,200–7,200 Å. The Hα emission line was observed to change significantly in shape and central wavelength on a time scale of ∼30 min. We set an upper limit to pulsations in the Hα line of 5% relative to the continuum.
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References
Sanford, P. W. & Ives, J. C. Proc. R. Soc. Lond. A 350, 491 (1976).
White, N. E., Mason, K. O., Huckle, H. E., Charles, P. A. & Sanford, P. W. Astrophys. J. Lett. 209, L119 (1976).
Becker, R. H. et al. Astrophys. J. 214, 879 (1977).
Boldt, E., Holt, S. S., Rothschild, R. E. & Serlemitsos, P. J. Astr. Astrophys. 50, 161 (1976).
Dower, R. G. et al. Nature 273, 364–367 (1978).
Bradt, H. V. et al. Nature 269, 21 (1977).
Maraschi, L., Treves, A. & Van den Heuvel, E. P. J. Nature 259, 292 (1976).
Boksenberg, A. & Burgess, D. E. Proc. Symp. on Astronomical Observations with Television-Type Sensors, Vancouver (1973).
Feast, M. W., Story, R. H., Thackeray, A. D. & Wesselink, A. J. Mon. Not. R. astr. Soc. 122, 239 (1961).
Gray, D. F. & Desikachary, K. Astrophys. J. 181, 523 (1973).
White, N. E. IAU Circ. No 3118 (1977).
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WHITE, N., PARKES, G., SANFORD, P. et al. Two X-ray periodicities from the vicinity of 4U1145–61. Nature 274, 664–666 (1978). https://doi.org/10.1038/274664a0
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DOI: https://doi.org/10.1038/274664a0
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