Oral Presentation

First K-band interferometric survey of previously unresolved Herbig~Ae/Be stars with VLTI/GRAVITY and CHARA

Author(s): Anuroop Dasgupta

Presenter: Anuroop Dasgupta (European Southern Observatory)

The inner regions of protoplanetary disks around Herbig Ae/Be stars, where dust sublimates and terrestrial planets may form, can only be spatially resolved with near-infrared interferometry. Previous surveys have characterized the brightest Herbig stars, but a systematic study of fainter targets has been lacking.
We present the first K-band interferometric survey of 13 previously unresolved Herbig Ae/Be stars observed with VLTI/GRAVITY and CHARA/MIRCX-MYSTIC. Visibilities and closure phases were modeled using geometric fitting with PMOIRED and a temperature gradient model (TGM), complemented by companion detection limits and spatially resolved Brackett gamma line analysis.
All targets are resolved, with half-flux radii of 0.36 to 3.19 AU, populating the undersampled low-to-intermediate luminosity range of the size-luminosity relation. Two binary companions are detected, with mass upper limits of 37 to 284 Jupiter masses for the remaining targets. Brackett gamma emission is spatially resolved in two systems, with emitting regions significantly more compact than the dust continuum, providing direct evidence for gas inside the dust sublimation radius. The TGM reveals temperature profiles steeper than passive irradiated disk predictions for most targets. We identify two transition disk candidates, report the first interferometric detection of a dipper event in V1650 Ori confirming inner rim occultation, and identify HIP 3401 as a FUor-like Herbig Be star with a compact accretion-heated inner disk. These results highlight the diversity of inner disk properties revealed when extending interferometric surveys to fainter Herbig stars.