The infrared temporal evolution of FG Sagittae

Charles E. Woodward, G. F. Lawrence, R. D. Gehrz, Terry J. Jones, H. A. Kobulnicky, James Cole, Tracy Hodge, Harley A. Thronson

Research output: Contribution to journalArticlepeer-review

37 Scopus citations

Abstract

We present near- and mid-infrared photometry of the post-AGB star FG Sge obtained at two distinct epochs separated by a period of 10 years. Observations of FG Sge taken in 1983 suggest that the 1 to 12 μm energy distribution was produced at that time by a stellar photosphere, with a blackbody temperature of ≈5600 K. In late August of 1992, FG Sge exhibited a marked decline (≈3 mag in V) in its visible light curve. At the same time the 1 to 18.0 μm infrared energy distribution has evolved to become a ≈1000 K blackbody. We propose that this light decline partially is due to the ejection and condensation of a dust shell. We estimate the amount of dust condensed during this episode to be ≈3.3 × 10-9 M, with a covering factor (total visual depth) of ≈0.3.

Original languageEnglish (US)
Pages (from-to)L37-L40
JournalAstrophysical Journal
Volume408
Issue number1 PART 2
DOIs
StatePublished - 1993

Keywords

  • Circumstellar matter
  • Stars individual: (FG Sagittae)
  • Stars: Evolution

Fingerprint

Dive into the research topics of 'The infrared temporal evolution of FG Sagittae'. Together they form a unique fingerprint.

Cite this