IUE observations of the late-type M supergiant TV Gem (M1 lab) have been obtained that reveal strong UV continuum between 1200 and 3200 A. The continuum is essentially featureless with the exception of a number of broad absorption features in the short wavelength spectral range. UV emission from this star is unexpected because earlier ground-based observations give no indication of a possible association with an early companion or circumstellar ionized nebulosity. We find that a B9 or A1 III-IV type star approximately 2-3 magnitudes fainter than the M star could explain the level of UV continuum observed, but a fully self-consistent explanation that includes the B-V color index of TV Gem is not as yet possible. The continuum flux dependence with wavelength in the UV spectral range could be attributed to a high-energy source such as an accretion disc. We suggest TV Gem as a good candidate for HEAO 2 (Einstein) satellite observations because a high-energy object in close proximity to the M star would likely be a source of soft X-ray emission.
Michalitsianos, A.G., Kafatos, M., Hobbs, R.W. (1980) IUE Observations of a Luminous M Supergiant that Exhibits Emission Continuum in the Far Ultraviolet, Astrophysical Journal, 241: 774-778. doi: 10.1086/158387