Mid- and Far-Infrared Variability of PV Cep

TL;DR

This study compiles mid- and far-infrared observations of PV Cep, confirming flux variability driven by accretion rate fluctuations and revealing a temperature-stratified circumstellar disk.

Contribution

It provides a comprehensive IR variability analysis of PV Cep, linking flux changes to accretion dynamics and disk structure, which was not previously detailed.

Findings

Mid-IR flux variability is prominent and not caused by extinction.

Variability is mainly due to accretion rate fluctuations and hot spot formation.

Far-IR data suggest a temperature-stratified circumstellar disk.

Abstract

We present the collection of all the mid- and far-IR observations (3-170 um) of the young eruptive variable PV Cep available so far in the literature. These data allow us to confirm that flux variability is a prominent feature at mid-IR wavelength (3-25 um). Color-magnitude plots clearly indicate that the observed variability is not extinction-driven, but mainly influenced by fluctuations of the mass accretion rate. We interpret such variability as due to a hot spot created onto the stellar surface by the column of accreting matter, which heats the inner parts of the disk and determines the observed increase of the near- mid-IR luminosity. A quantitative characterization is given for both the spot itself and the additional thermal component created by it. Far-IR data (60-170 um) are consistent with the presence of a temperature stratification in a massive and quite un-evolved circumstellar disk.