%0 Journal Article %@ 0035-8711 %A Sylvester, RJ %A Skinner, CJ %A Barlow, MJ %D 1998 %F discovery:10096081 %I BLACKWELL SCIENCE LTD %J Monthly Notices of the Royal Astronomical Society %K circumstellar matter, stars: mass-loss, supergiants, open clusters and associations: individual: h and χ Per, infrared: stars %N 4 %P 1083-1094 %T Silicate and hydrocarbon emission from Galactic M supergiants %U https://discovery.ucl.ac.uk/id/eprint/10096081/ %V 301 %X Following our discovery of unidentified infrared (UIR) band emission in a number of M supergiants in h and χ Per, we have obtained 10-μm spectra of a sample of 60 galactic M supergiants. Only three new sources, V1749 Cyg, UW Aql and IRC+40 427, appear to show the UIR bands; the others show the expected silicate emission or a featureless continuum. The occurrence of UIR-band emission in M supergiants is therefore much higher in the h and χ Per cluster than in the Galaxy as a whole. Possible explanations for the origin and distribution of UIR bands in oxygen-rich supergiants are discussed. We use our spectra to derive mass-loss rates ranging from 10−8 to 10−4 M⊙ yr−1 for the new sample, based on the power emitted in the silicate feature. The relationship between mass-loss rate and luminosity for M supergiants is discussed, and correlations are explored between their mid-infrared emission properties. %Z This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.