000007242 001__ 7242
000007242 005__ 20250106161332.0
000007242 0247_ $$2DOI$$a10.1051/0004-6361/202347293
000007242 037__ $$aSCART-2025-0018
000007242 100__ $$aTafoya, Daniel
000007242 245__ $$aThe heart of Sakurai's object revealed by ALMA
000007242 260__ $$c2023
000007242 520__ $$aWe present high-angular-resolution observations of Sakurai's object using the Atacama Large Millimeter Array, shedding new light on its morpho-kinematical structure. The millimetre continuum emission observed at an angular resolution of 20 milliarcsec (corresponding to 70 AU) reveals a bright compact central component whose spectral index indicates that it is composed of amorphous carbon dust. Based on these findings, we conclude that this emission traces the previously suggested dust disc observed in mid-infrared observations, and therefore our observations provide the first direct imaging of this disc. The H12CN(J = 4 → 3) line emission observed at an angular resolution of 300 milliarcsec (corresponding to 1000 AU) displays a bipolar structure with a north-south velocity gradient. From the position-velocity diagram of this emission, we identify the presence of an expanding disc and a bipolar molecular outflow. The inclination of the disc is determined to be i = 72°. The derived values for the de-projected expansion velocity and the radius of the disc are vexp = 53 km s−1 and R = 277 AU, respectively. On the other hand, the de-projected expansion velocity of the bipolar outflow detected in the H12CN(J = 4 → 3) emission is of approximately 1000 km s−1. We propose that the molecular outflow has an hourglass morphology with an opening angle of around 60°. Our observations unambiguously show that an equatorial disc and bipolar outflows formed in Sakurai's object during the 30 years following the occurrence of the born-again event, providing important constraints for future modelling efforts of this phenomenon.
000007242 594__ $$aNO
000007242 6531_ $$astars: low-mass; binaries: general; stars: winds; outflows; planetary nebulae: general; planetary nebulae: individual: Sakurai's object; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Astrophysics of Galaxies
000007242 700__ $$avan Hoof, Peter A. M.
000007242 700__ $$aToalá, Jesús A.
000007242 700__ $$aVan de Steene, Griet
000007242 700__ $$aRandall, Suzanna
000007242 700__ $$aUnnikrishnan, Ramlal
000007242 700__ $$aKimeswenger, Stefan
000007242 700__ $$aHajduk, Marcin
000007242 700__ $$aBarría, Daniela
000007242 700__ $$aZijlstra, Albert
000007242 773__ $$c8$$pAstronomy & Astrophysics$$v667$$y2023
000007242 8560_ $$fgriet.vandesteene@ksb-orb.be
000007242 85642 $$ahttps://ui.adsabs.harvard.edu/abs/2023A%26A...677L...8T/abstract
000007242 905__ $$apublished in
000007242 980__ $$aREFERD