... 3.1 Crystalline silicates Silicate minerals of the olivine and pyroxene classes have been shown to be present in out ows of evolved stars as well as in comets and protoplanetary disks. ...
... Silicate minerals of the olivine and pyroxene classes have been shown to be present in outflows of evolved stars as well as in comets and protoplanetary disks. ...
... Crystalline silicates Silicate minerals of the olivine and pyroxene classes have been shown to be present in out ows of evolved stars as well as in comets and protoplanetary disks. ...
... patterns have been observed in bipolar and cometary nebulae (Scarrott et al. 1989), young stellar objects (Ha jjar & Bastien 1996), evolved stars (Kastner & Weintraub 1996), and are also clearly seen in polarization maps of comets (Dollfus & Suchail 1987 ...