Temporal Variations of Midinfrared Spectra in Late-Type Stars

  title={Temporal Variations of Midinfrared Spectra in Late-Type Stars},
  author={John D. Monnier and T. R. Geballe and William C. Danchi},
  journal={The Astrophysical Journal},
New multiepoch, midinfrared (8-13 μm) spectrophotometric observations are presented for 30 late-type stars. The observations were collected over a 4 yr period (1994-1997), permitting an investigation of the midinfrared spectral shape as a function of the pulsation cycle (typically 1-2 yr). The spectra of stars with little excess infrared emission and those with carbon-rich dust show the least spectral variability, while stars with evidence for dusty, oxygen-rich envelopes are most likely to… 

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