SIMBAD references

Searching for C₇H and C₈H in the carbon star envelope IRC+10216, we have identified 10 lines with harrnonically related frequencies and with regularly increasing intensities (3 lines in the IRAM 3mm spectral survey and 7 lines in the 7mm Nobeyama survey of Kawaguchi et al., 1995). The rest frequencies can be closely fitted with the standard expression for the energies of a linear molecule with a rotational constant B=586.676MHz, a distortion constant D=6.3Hz, and half-integer quantum numbers J. The value of B is within 0.1% of that predicted by Pauzat et al. (1991) for the ²{PI} ground state of C₈H and the value of D typical of a linear acetylenic chain of C₈H's weight. Since the half-integer J numbers are also consistent with a ²{PI} state, we concluded that we had very probably discovered C₈H. In the an accompanying Letter, McCarthy et al. report the detection of 30 lines of our new radical in an acetylene discharge and confirm they arise from C₈H.