SIMBAD references

Following our discovery of C₈H in IRC+10216 (Cernicharo & Guelin 1996A&A...309L..27C), we report the detection in this circumstellar envelope of another linear carbon chain radical, C₇H. The microwave spectrum of C₇H has been recently observed in the laboratory (Travers et al. 1996ApJ...465L..77T) and its rotational line frequencies are precisely known. With this new detection, the family of acetylenic chain radicals (C_nH) observed in space is complete up to n=8. The members with even numbers of carbon atoms are consistently more abundant than the odd number members; C₇H is found to be a factor of 4 less abundant than C₈H and a factor of 20 less abundant than C₅H.