QU Vulpeculae
QU Vulpeculae, also known as Nova Vulpeculae 1984 Number 2, was the second nova which occurred in 1984 in the constellation Vulpecula (PW Vulpeculae was the first). It was discovered by Peter Collins, an amateur astronomer from Cardiff, California at 22:08 UT on 22 December 1984. At the time of its discovery, the nova's apparent magnitude was 6.8. By the next night, Collins reported its brightness had increased to magnitude 5.6, making it visible to the naked eye. QU Vulpeculae declined from peak brightness quite rapidly, and had faded by 3 magnitudes in just 40 days, so it is classified as a "fast" nova. All nova are binary stars, with a "donor" star orbiting a white dwarf. The two stars are so close to each other that material is transferred from the donor to the white dwarf. Since the two stars are separated by a distance comparable to the radius of the donor star, novae are often found to be eclipsing binaries, and QU Vulpeculae shows such eclipses. The eclipses produce a ~0.5 magnitude brightness drop, and they allow the orbital period, 2.68 hours, to be measured. This is an unusual orbital period for a cataclysmic variable star, falling within