Limits on molecular emission from the planetary nebula associated with Sakurai’s Object

We have observed Sakurai’s object in the S(1)λ2.121
line of H2 and in the J = 2 → 1 line of 12CO. We give upper
limits on the H2 and 12CO emission from the planetary nebula
associated with this object. Assuming a distance of 3.8 kpc, we
obtain an upper limit on the mass of molecular hydrogen in the
planetary nebula of 1.8 10−4 M for an excitation temperature
of 1000 K and, for an excitation temperature of 25 K, an upper
limit of 1.5 10−5 M on the mass of CO.