2015/06/03 by Christopher Wright, C. M. Wright, Sarah Maddison +13
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Galaxy #Physics #Planet #Position angle #RADIUS #Resolution (logic) #Stellar, planetary, and galactic studies #Surface brightness #Telescope #astro-ph.SR
paper · pdf · doi:10.1093/mnras/stv1619
Accepted for publication in Monthly Notices of the Royal Astronomical Society
arxiv created 2015/06/03 · openalex publication_date 2015/08/13 · arxiv updated 2016/03/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
There is much evidence that planet formation is occurring in the disc around the Herbig Be star HD100546. To learn more about the processes occurring in this disc, we conducted high-resolution imaging at 43/45 GHz with the Australia Telescope Compact Array. Multiple array configurations were used, providing a best spatial resolution of 0.15 arcsec, or 15 au at HD100546's distance of 100 pc. Significant structure is revealed, but its precise form is dependent on the u -v plane sampling used for the image reconstruction. At a resolution of 30 au, we detected an inner gap in the disc with a radius of 25 au and a position angle approximately along the known disc major axis. With different weighting, and an achieved resolution of 15 au, emission appears at the centre and the disc takes on the shape of an incomplete ring, much like a horseshoe, again with a gap radius of 25 au. The position angle of the disc major axis and its inclination from face-on are determined to be 140 5 and 40 5 , respectively. The 25 au gap radius is confirmed by a null in the real part of the binned visibilities at 320 10 k, whilst the non-axisymmetric nature is also confirmed through significant structure in the imaginary component. The emission mechanism at the central peak is most likely to be free-free emission from a stellar or disc wind. Overall our data support the picture of at least one, but probably several, giant planets orbiting HD100546 within 25 au.