The first 8–13 μm spectra of globular cluster red giants: circumstellar silicate dust grains in 47 Tucanae (NGC 104)
Astrophysics Group, School of Physical & Geographical Sciences, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG, UK e-mail: email@example.com
2 Department of Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455, USA
Accepted: 2 January 2006
We present 8–13 μm spectra of eight red giants in the globular cluster 47 Tucanae (NGC 104), obtained at the European Southern Observatory 3.6 m telescope. These are the first mid-infrared spectra of metal-poor, low-mass stars. The spectrum of at least one of these, namely the extremely red, large-amplitude variable V1, shows direct evidence of circumstellar grains made of amorphous silicate.
Key words: stars: AGB and post-AGB / circumstellar matter / stars: evolution / stars: mass-loss / infrared: stars / globular clusters: individual: 47 Tucanae (NGC 104)
© ESO, 2006