V488 Per revisited: no strong mid-infrared emission features and no evidence for stellar/sub-stellar companions

TL;DR

This study characterizes the dust and planetary system of V488 Per, revealing a lack of mid-infrared emission features and no evidence of companions, suggesting unique dust grain properties and possible planet formation activity.

Contribution

It provides detailed infrared observations of V488 Per, showing unusual dust properties and absence of companions, advancing understanding of dust composition and planetary system architecture.

Findings

Outer dust population at ~130 K confirmed

No solid-state emission features detected in mid-infrared

No stellar or sub-stellar companions found within several hundred AU

Abstract

We present characterization of the planetary system architecture for V488 Per, the dustiest main sequence star known with a fractional infrared luminosity of ~16%. Far-infrared imaging photometry confirms the existence of an outer planetary system dust population with blackbody-fit temperature of ~130 K. Mid-infrared spectroscopy probing the previously-identified ~800 K inner planetary system dust population does not detect any obvious solid-state emission features, suggesting either large grain sizes that mute such emission and/or grain compositions dominated by species like amorphous carbon and metallic iron which do not produce such features. In the latter case, the presence of significant quantities of iron-rich material could be indicative of the active formation of a Mercury-like planet around V488 Per. In any event, the absence of solid-state emission features is very unusual among main sequence stars with copious amounts of warm orbiting dust particles; we know of no other such star whose mid-infrared spectrum lacks such features. Combined radial velocity monitoring and adaptive optics imaging find no evidence for stellar/sub-stellar companions within several hundred AU of V488 Per.