The orbital period of the V Sge star candidate QU Carinae

Close binary supersoft X-ray sources (CBSS) are considered strong candidates to Type Ia supernova progenitors, but very few CBSS are known in our Galaxy. The Galactic counterparts of the CBSS may be the V Sge stars, not detected in X-rays due to the strong absorption by the interstellar gas. Nevertheless, the number of members in the V Sge class is still small. In order to find new members, we sel...