A likely planet-induced gap in the disc around T Cha

Nathanial P. Hendler, Paola Pinilla, Ilaria Pascucci, Adriana Pohl, Gijs Mulders, Thomas Henning, Ruobing Dong, Cathie Clarke, James Owen, David Hollenbach

Research output: Contribution to journalArticlepeer-review

34 Scopus citations


We present high-resolution (0.11 × 0.06 arcsec2) 3 mm ALMA observations of the highly inclined transition disc around the star T Cha. Our continuum image reveals multiple dust structures: an inner disc, a spatially resolved dust gap, and an outer ring. When fitting sky-brightness models to the real component of the 3 mm visibilities, we infer that the inner emission is compact (≤1 au in radius), the gap width is between 18 and 28 au, and the emission from the outer ring peaks at ∼36 au. We compare our ALMA image with previously published 1.6 µm VLT/SPHERE imagery. This comparison reveals that the location of the outer ring is wavelength dependent. More specifically, the peak emission of the 3 mm ring is at a larger radial distance than that of the 1.6 µm ring, suggesting that millimeter-sized grains in the outer disc are located farther away from the central star than micron-sized grains. We discuss different scenarios to explain our findings, including dead zones, star-driven photoevaporation, and planet-disc interactions. We find that the most likely origin of the dust gap is from an embedded planet, and estimate - for a single planet scenario - that T Cha's gap is carved by a 1.2MJup planet.

Original languageEnglish
Pages (from-to)L62-L66
JournalMonthly Notices of the Royal Astronomical Society: Letters
Issue number1
StatePublished - 1 Mar 2018
Externally publishedYes


  • Circumstellar matter
  • Planet-disc interactions
  • Planets and satellites: detection
  • Planets and satellites: formation
  • Protoplanetary discs


Dive into the research topics of 'A likely planet-induced gap in the disc around T Cha'. Together they form a unique fingerprint.

Cite this