The Discontinuity in the Ultraviolet
Bechtold et al. (1984)
have measured the continuum energy distribution of 0237-233
with the International Ultraviolet Explorer and the Palomar 5 meter multichannel
spectro-photometer. A discontinuity was found in the ultraviolet and these authors state that
it occurs at 2350±10 Å. On the other hand, from the PLS model, for an atmosphere
rich in He I, we expect a discontinuity at 2600 Å (the ionization limit from the 1s2s 3S
state). To examine the problem carefully, we show in Figure 1, the observed data
reported by
Bechtold et al. (1984).
The positions of 2350 and 2600 Å are indicated.
There is an observed point at 2614 Å, but as shown in the figure, it has very large error
bars. Allowing for this large uncertainty, the observed data are consistent with a
discontinuity at 2600 Å. We predict that more accurate observations will confirm the
expected discontinuity at 2600 Å.
Fig.1. Continuum spectral energy distribution of 0237-233.
Next Section: Similarities with Upsilon Sagitarii