Evans, A, Gehrz, RD, Woodward, CE, Sarre, PJ, van Loon, JT, Helton, LA, Starrfield, S, Eyres, SPS, Evans, A, Gehrz, RD, Woodward, CE, Sarre, PJ, van Loon, JT, Helton, LA, Starrfield, S, and Eyres, SPS
We present observations of CK Vul obtained with the Spitzer Space Telescope. The infrared spectrum reveals a warm dust continuum with nebular, molecular hydrogen and HCN lines superimposed, together with the `Unidentified Infrared' features. The nebular lines are consistent with emission by a low-density gas. We conclude that the Spitzer data, combined with other information, are incompatible with CK Vul being a classical nova remnant in `hibernation' after the event of 1670, a `very late thermal pulse', a `Luminous Red Variable', such as V838 Mon, or a `diffusion-induced nova'. The true nature of CK Vul remains a mystery.