Changes in Polarization, Light and Colour during the Outburst Stage of the Recurrent Nova T Pyxidis

WE were notified on December 8, 1966, by Mr. Frank Bateson, of the discovery in New Zealand by Mr. Albert Jones that the recurrent Nova T Pyx was at visual magnitude 12.9 on December 7. Previous estimates had placed the nova near magnitude 14.5 for some years. Photometric and polarimetric observations, with the 40 in. and 24 in. reflectors at Siding Spring Mountain, began on the night of December 8-9. The photometric observations during the pre-maximum and maximum phases of the outburst are shown in Table 1 and in Fig. 1. The trends of the variation in visual magnitude, during the gaps in the observations caused by clouds at Siding Spring Mountain, are shown in Fig. 1 by broken curves and are based on visual observations by V. L. Matchett and M. Jones of the Moreton Bay Astronomical Club. A slight adjustment was necessary to bring the visual observations into agreement with the photoelectric results. Previous outbursts of the nova were in 1890, 1902, 1920 and 1944 and the light curve in Fig. 1 is strikingly similar to those obtained in 1902, 1920 and 1944¹.