CK Vulpeculae (also Nova Vulpeculae 1670) may be the oldest cataloged nova variable. It consists of a central dim object with gas flowing out (~ 210 kilometres per second) into a bi-polar nebulous blob. It is either inside of a cloud of cold (~ 15 K) dust or the cloud is in front of it from the Earth's perspective. Molecular gas in the vicinity is rich in nitrogen relative to oxygen. Models suggest CK Vulpeculae may not be a classic nova; rather it may be classified as a Luminous red nova which is the result of two main sequence stars colliding and merging.
Eruptive history
CK Vulpeculae was discovered by Voituret Anthelme in 1670. It had a brightness maximum of approximately magnitude 3 on June 20, 1670 after which it faded. A second maxima was observed March 1671, after which Johannes Hevelius and Giovanni Cassini observed it throughout spring and summer until it faded from naked-eye view in late August 1671. A last weakly visible brightness maxima of approximately 5.5 to 6 magnitude was observed by Hevelius in March 1672 and finally faded from view late May. Observers from 1670 to 1672 noted the nova had a reddish colour. John Flamsteed, who was elaborating his catalogue during these years, assigned the star the Flamsteed designation 11 Vulpeculae, which has been noted later by Francis Baily as one of Flamsteed lost stars, due to the fact that it has not been detectable for centuries until recovered in 1981.