SELF

68

O.N. Karavashkina and S.B. Karavashkin

Until the rotation speed is small, the star will involve the surrounding substance of mother cloud and join it to the body of protostar, but when it achieved the break-off speed, the star becomes the autonomous body. So we see that this break-off is also determined by the magnetic field of star.

Furthermore, the centrifugal forces will stimulate the "drain off" of the substance of exterior cocoon to equator, due to which as a general rule the envelope will be denser at the equator and rarer at the poles - just as we see on some stars that are turned to us with their poles. We have now a beautiful example of nova V 836 of Monoceros (see Fig. 2.17) whose magnetic axis is oriented along the observation direction and this enables us to see the envelop dense at the equator and transparent at the poles.

Fig. 2.17. Swelling envelop of V 836 of Monoceros [12].

Its swelling envelop (we will analyse such envelops below) enables us to take a glance inside, between the envelop and core. We can distinctively see in the photo that at the initial stage of swell the polar region is small and the star only slightly peeps through the polar gap in the envelop. But the rarefied space between the convection layer of core and envelop of which we are speaking has already formed. With it the envelope itself is quite dense and opaque. As the envelope swells, it rarefies, becomes more transparent and shows its interior region. We even see through it the light of behind stars. However we see, only the envelope swells, not the convective layer, this is why it rarefies in time.

When in the course of evolution the star bursts and we can observe its depths and envelope, we see the same phenomenon, only in matchless greater scale: "when E.R. Mustel and A.A. Boyarchuk analysed the photographs of flying apart envelops [11], it showed that the envelops are arranged non-symmetrical - they have a shape of an equatorial ring and polar clusters … Such asymmetry can be caused only by a significant magnetic field of the bursting white dwarfs" [4, p. 121].

Fig. 2.18. Spectral energy distribution of 55 Cancri, combining SCUBA, ISO, Keck and Simbad data for the optical through submillimetre fluxes (Jayawardhana et al. 1999). The solid line represents a radiative transfer model fit to the data. Copied from [6], http://www.ifa.hawaii.edu/research

One more example of rarefied region between the electron cocoon and convective layer we can see in Fig. 2.18 where is presented the result of spectrometric measurements of 55 Cancri unified from the observations of four satellites - SCUBA, ISO, Keck ? Simbad. In the right image, we see around the core the same distinctive ring layer that, apparently, enough strongly screens the core, so it is so weakly observed. The left plot corroborates the made supposition. We can see in this plot that at 25 arc seconds there is the minimum of radiation, and the central maximum at 10 arc seconds is more than that peripheral. Proceeding from the above analysis, we can suppose that the magnetic axis of 55 Cancri is also directed towards us, or otherwise the diagram would not show so regular circle but would be deformed, or it would not have at all so clear ring maximums.