SOFIA/FORCAST Observations of the Luminous Blue Variable Candidates MN 90 and HD 168625

Ryan A. Arneson, Dinesh Shenoy, Nathan Smith, Robert D. Gehrz

Research output: Contribution to journalArticle

Abstract

We present Stratospheric Observatory for Infrared Astronomy (SOFIA)/Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST) imaging of the circumstellar dust shells surrounding the luminous blue variable candidates MN 90 and HD 168625 to quantify the mineral abundances of the dust and to constrain the evolutionary state of these objects. Our image at 37.1 μm of MN 90 shows a limb-brightened, spherical dust shell. A least-squares fit to the spectral energy distribution of MN 90 yields a dust temperature of 59 ± 10 K, with the peak of the emission at 42.7 μm. Using 2-Dust radiative transfer code, we estimate for MN 90 that mass loss occurred at a rate of (7.3 ± 0.4) × 10-7 × (v exp/50 ) to create a dust shell with a dust mass of (3.2 ± 0.1) × 10-2 . Our images between 7.7 and 37.1 μm of HD 168625 complement previously obtained mid-IR imaging of its bipolar nebulae. The SOFIA/FORCAST imaging of HD 168625 shows evidence for the limb-brightened peaks of an equatorial torus. We estimate a dust temperature of 170 ± 40 K for the equatorial dust surrounding HD 168625, with the peak of the emission at 18.3 μm. Our 2-Dust model for HD 168625 estimates that mass loss occurred at a rate of (3.2 ± 0.2) × 10-7 to create a dust torus/shell with a dust mass of (2.5 ± 0.1) × 10-3 .

Original languageEnglish (US)
Article number31
JournalAstrophysical Journal
Volume864
Issue number1
DOIs
StatePublished - Sep 1 2018

Keywords

  • MN 90)
  • circumstellar matter
  • stars: individual (HD 168625
  • stars: mass-loss
  • stars: massive

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'SOFIA/FORCAST Observations of the Luminous Blue Variable Candidates MN 90 and HD 168625'. Together they form a unique fingerprint.

  • Cite this