DISCOVERY AND IMAGING OF A GALACTIC CIRRUS CLOUD WITH THE FAR-ULTRAVIOLET SPACE TELESCOPE

We present new far-ultraviolet (1400-1800 Angstrom) data concerning a Galactic cirrus cloud G251.2+73.3 near the north Galactic pole obtaine d with the space-borne imaging telescope FAUST. We obtain a good corre lation between the far-ultraviolet (FUV) and IRAS 100 mu m surface bri ghtnesses, their relation being I-FUV = (128 +/- 3)I-100 mu m - (264 /- 9), where the I-FUV flux is given in units of photons s(-1) cm(-2) Angstrom(-1) sr(-1) and I-100 mu m in MJy sr(-1). Using uvbyH beta pho tometry, we get a distance of 120 pc and a visual extinction in the ce nter of the cloud of 0.39 mag corresponding to an extinction of 1.0 ma g at 1565 Angstrom. We have performed a multiple scattering calculatio n for the scattered light using the Monte Carlo method. These calculat ions provide restrictions on the FUV scattering properties of the inte rstellar dust.