High-fidelity Imaging of the Inner AU Mic Debris Disk: Evidence of Differential Wind Sculpting? - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles The Astrophysical journal letters Year : 2019

High-fidelity Imaging of the Inner AU Mic Debris Disk: Evidence of Differential Wind Sculpting?

John P. Wisniewski
  • Function : Author
Adam F. Kowalski
  • Function : Author
James R. A. Davenport
  • Function : Author
Glenn Schneider
  • Function : Author
Carol A. Grady
  • Function : Author
Leslie Hebb
  • Function : Author
Kellen D. Lawson
  • Function : Author
Alexander Brown
  • Function : Author
John H. Debes
  • Function : Author
Andras Gaspar
  • Function : Author
Thomas K. Henning
  • Function : Author
Dean C. Hines
  • Function : Author
Marc J. Kuchner
  • Function : Author
Julien Milli
  • Function : Author
Christopher C. Stark
  • Function : Author
Christian Thalmann
  • Function : Author

Abstract

We present new high-fidelity optical coronagraphic imagery of the inner ∼50 au of AU Mic’s edge-on debris disk using the BAR5 occulter of the Hubble Space Telescope Imaging Spectrograph (HST/STIS) obtained on 2018 July 26-27. This new imagery reveals that “feature A,” residing at a projected stellocentric separation of 14.2 au on the southeast side of the disk, exhibits an apparent “loop-like” morphology at the time of our observations. The loop has a projected width of 1.5 au and rises 2.3 au above the disk midplane. We also explored Transiting Exoplanet Survey Satellite photometric observations of AU Mic that are consistent with evidence of two starspot complexes in the system. The likely co-alignment of the stellar and disk rotational axes breaks degeneracies in detailed spot modeling, indicating that AU Mic’s projected magnetic field axis is offset from its rotational axis. We speculate that small grains in AU Mic’s disk could be sculpted by a time-dependent wind that is influenced by this offset magnetic field axis, analogous to co-rotating solar interaction regions that sculpt and influence the inner and outer regions of our own Heliosphere. Alternatively, if the observed spot modulation is indicative of a significant misalignment of the stellar and disk rotational axes, we suggest that the disk could still be sculpted by the differential equatorial versus polar wind that it sees with every stellar rotation.
Fichier principal
Vignette du fichier
Wisniewski_2019_ApJL_883_L8.pdf (1.02 Mo) Télécharger le fichier
Origin Publisher files allowed on an open archive

Dates and versions

insu-03703557 , version 1 (24-06-2022)

Licence

Identifiers

Cite

John P. Wisniewski, Adam F. Kowalski, James R. A. Davenport, Glenn Schneider, Carol A. Grady, et al.. High-fidelity Imaging of the Inner AU Mic Debris Disk: Evidence of Differential Wind Sculpting?. The Astrophysical journal letters, 2019, 883, ⟨10.3847/2041-8213/ab40bf⟩. ⟨insu-03703557⟩
15 View
8 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More