Interstellar Extinction and Interstellar Lines in Two Close Stars Near Orion B

A small amount of IUE observing time is requested to observe one pair of stars, HD 37903 + HD 37744, on either side of the Horsehead. The stars are of equal spectral type but have quite different extinction. ANS observations probably were contaminated by diffuse light and so the anomality of the extinction curve derived from these stars is questionable. Because the stars are separated by only 40 arc min, the fainter one 100 pc farther away, they provide a unique possibility to study the interstellar gas by way of its resonance lines: the foreground effects are equal, the conditions in the gas near each star are vary different.