Variability of disk emission in pre-main sequence and related stars. III. Exploring structural changes in the pre-transitional disk in HD 169142

Kevin R. Wagner, Michael L. Sitko, Carol A. Grady, Jeremy R. Swearingen, Elizabeth H. Champney, Alexa N. Johnson, Chelsea Werren, Barbara A. Whitney, Ray W. Russell, Glenn H. Schneider, Munetake Momose, Takayuki Muto, Akio K. Inoue, James T. Lauroesch, Jeremy Hornbeck, Alexander Brown, Misato Fukagawa, Thayne M. Currie, John P. Wisniewski, Bruce E. Woodgate

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


We present near-IR (NIR) and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy distribution reveals variability of up to 45% between ∼1.5-10 μm over a maximum timescale of 10 yr. All observations known to us separate into two distinct states corresponding to a high near-IR state in the pre-2000 epoch and a low state in the post-2000 epoch, indicating activity within the ≲1 AU region of the disk. Through analysis of the Pa β and Br γ lines in our data we derive a mass accretion rate in 2013 May of ≈ (1.5-2.7) × 10-9 M yr-1. We present a theoretical modeling analysis of the disk in HD 169142 using Monte-Carlo radiative transfer simulation software to explore the conditions and perhaps signs of planetary formation in our collection of 24 yr of observations. We find that shifting the outer edge (r ≈ 0.3 AU) of the inner disk by 0.05 AU toward the star (in simulation of accretion and/or sculpting by forming planets) successfully reproduces the shift in NIR flux. We establish that the ∼40-70 AU dark ring imaged in the NIR by Quanz et al. and Momose et al. and at 7 mm by Osorio et al. may be reproduced with a 30% scaled density profile throughout the region, strengthening the link to this structure being dynamically cleared by one or more planetary mass bodies.

Original languageEnglish (US)
Article number94
JournalAstrophysical Journal
Issue number2
StatePublished - Jan 10 2015


  • planet-disk interactions
  • protoplanetary disks
  • stars: individual (HD 169142)
  • stars: variables: T Tauri, Herbig Ae/Be
  • techniques: photometric
  • techniques: spectroscopic

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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