Year: 2021
Type: article
Abstract: ABSTRACT This article reports quasi-continuous transiting events towards WD 1054–226 at d = 36.2 pc and V = 16.0 mag, based on simultaneous, high-cadence, multiwavelength imaging photometry using ULTRACAM over 18 nights from 2019 to 2020 March. The predominant period is 25.02 h and corresponds to a circular orbit with blackbody Teq = 323 K, where a planetary surface can nominally support liquid water. The light curves reveal remarkable night-to-night similarity, with changes on longer time-scales, and lack any transit-free segments of unocculted starlight. The most pronounced dimming components occur every 23.1 min – exactly the 65th harmonic of the fundamental period – with depths of up to several per cent, and no evident colour dependence. Myriad additional harmonics are present, as well as at least two transiting features with independent periods. High-resolution optical spectra are consistent with stable, photospheric absorption by multiple, refractory metal species, with no indication of circumstellar gas. Spitzer observations demonstrate a lack of detectable dust emission, suggesting that the otherwise hidden circumstellar disc orbiting WD 1054–226 may be typical of polluted white dwarfs, and detected only via favourable geometry. Future observations are required to constrain the orbital eccentricity, but even if periastron is near the Roche limit, sublimation cannot drive mass loss in refractory parent bodies, and collisional disintegration is necessary for dust production.
Institutions: University College London, Boston University, University of Warwick, Lund University, University of Cambridge, University of St Andrews, Wesleyan University, Universidad de La Laguna, Universidad Técnica Federico Santa María, Naresuan University, Instituto de Astrofísica de Canarias, University of Sheffield
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: G1068495088, G1284384369, G1302280899, A consolidated grant for Sheffield Astrophysics 2021-2024, UCL Astrophysics Consolidated Grant 2018-2021, Kinematics, Galactic Age, Chemistry and Water Fraction of Asteroid-Polluted White Dwarfs from the Sloan Digital Sky Survey, Warwick Astronomy and Astrophysics Consolidated Grant 2020-2023, Archaeology of Exo-Terrestrial Planetary Systems and a Search for Water, Astronomy at St Andrews 2015-2018, G3544563273, G380734552, G4474684054, G5338142952, G6609624996, G7305630172, A unified picture of white dwarf planetary systems, G8117598032
OpenAlex ID: W4206136173