Abstract
Abstract We present follow-up photometry and spectroscopy of ZTF J0328−1219, strengthening its status as a white dwarf exhibiting transiting planetary debris. Using TESS and Zwicky Transient Facility photometry, along with follow-up high-speed photometry from various observatories, we find evidence for two significant periods of variability at 9.937 and 11.2 hr. We interpret these as most likely the orbital periods of different debris clumps. Changes in the detailed dip structures within the light curves are observed on nightly, weekly, and monthly timescales, reminiscent of the dynamic behavior observed in the first white dwarf discovered to harbor a disintegrating asteroid, WD 1145+017. We fit previously published spectroscopy along with broadband photometry to obtain new atmospheric parameters for the white dwarf, with M ⋆ = 0.731 ± 0.023 M ⊙, T eff = 7630 ± 140 K, and [Ca/He] = − 9.55 ± 0.12. With new high-resolution spectroscopy, we detect prominent and narrow Na D absorption features likely of circumstellar origin, with velocities 21.4 ± 1.0 km s−1 blueshifted relative to atmospheric lines. We attribute the periodically modulated photometric signal to dusty effluents from small orbiting bodies such as asteroids or comets, but we are unable to identify the most likely material that is being sublimated, or otherwise ejected, as the environmental temperatures range from roughly 400 to 700 K.
Highlights
White dwarfs, the most common endpoint of stellar evolution, are likely to host planetary systems which et al 2020a; Xu et al 2020), and in a small number of these objects, metallic emission lines due to a hot gaseous component of the debris disk (Gansicke et al 2006; Dennihy et al 2020b; Melis et al 2020; Gentile Fusillo et al 2020)
After the initial identification of Zwicky Transient Facility (ZTF) J0328-1219 as a transiting planetary debris candidate due to its metal pollution and short-timescale variability (Guidry et al 2021), we set out to investigate whether this object, like the two known dust cloud transiting systems WD 1145+017 and ZTF J0139+5245, exhibits periodic variability related to the orbital period of planetary debris
In this work we have presented new and archival observations which confirm ZTF J0328−1219 as the third white dwarf to exhibit recurring transits caused by orbiting debris clouds
Summary
The most common endpoint of stellar evolution, are likely to host planetary systems which et al 2020a; Xu et al 2020), and in a small number of these objects, metallic emission lines due to a hot gaseous component of the debris disk (Gansicke et al 2006; Dennihy et al 2020b; Melis et al 2020; Gentile Fusillo et al 2020) These observational signatures are generally agreed to be the result of the tidal disruption of a planetary body after being gravitationally perturbed onto a highly eccentric orbit by one or more of the surviving outer planets (Debes & Sigurdsson 2002; Jura 2003). Regardless of the mechanism that is disrupting planetary bodies, it is likely that a broad distribution of orbital periods could be observable among this class of objects, and confirming more such objects is needed to empirically fill out and understand this distribution
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
