Letter | Published:

Identification of GX3+1 from Lunar Occultations

  • A Corrigendum to this article was published on 10 August 1973


THE position of GX3+1 has previously been reported by Schnopper et al.1 with sufficient accuracy to allow the times of lunar occultations to be predicted to within about ±3 min2. This uncertainty in the predicted time can be covered by the relatively brief observation period of the flight of a sounding rocket. Two of the present cycle of lunar occultations were predicted for the rocket range at Woomera, Australia, and were successfully observed: the first on September 27, 1971, by the Leicester X-ray Astronomy Group, and the second on October 24, 1971, by the Mullard Space Science Laboratory, UCL.

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  1. 1

    Schnopper, H. W., Bradt, H. V., Rappaport, S., Boughan, E., Barnell, B., Doxsey, R., Mayer, W., and Watt, S., Astrophys. J. Lett., 161, L161 (1970).

  2. 2

    Morrison, L. V., Nature Physical Science, 229, 192 (1971).

  3. 3

    Griffiths, R. E., Cooke, B. A., and Pounds, K. A., Nature Physical Science, 229, 175 (1971).

  4. 4

    IAU, Trans. Intern. Astron. Union, 13 B, 49 (1967).

  5. 5

    Kunkel, W., Osmer, P., Smith, M., Hoag, A., Schroeder, D., Hiltner, W. A., Bradt, H., Rappaport, S., and Schnopper, H. W., Astrophys. J. Lett., 161, L169 (1970).

  6. 6

    Watts, C. B., Astron. Pap. XVII (Washington, 1963).

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