A New Analysis of the O VI Emitting Nebula around KPD 0005+5106

TL;DR

This study analyzes the O VI emitting nebula around the hot white dwarf KPD 0005+5106 using ultraviolet observations and photoionization models, revealing circumstellar material causing significant attenuation of stellar flux.

Contribution

It provides a revised analysis incorporating new and reprocessed data, and models the nebula considering the star's updated temperature and circumstellar attenuation.

Findings

Nebula density is about 10 cm^-3

Stellar flux is attenuated by approximately 90%

Circumstellar material affects nebula ionization

Abstract

We present observations of O VI 1032 emission around the helium white dwarf KPD 0005+5106 obtained with the Far Ultraviolet Spectroscopic Explorer. Previously published data, reprocessed with an updated version of the calibration pipeline, are included along with new observations. The recent upward revision of the white dwarf's effective temperature to 200,000 K has motivated us to re-analyze all the data. We compare observations with photoionization models and find that the density of the O VI nebula is about 10 cm^-3, and that the stellar flux must be attenuated by about 90% by the time it impinges on the inner face of the nebula. We infer that this attenuation is due to circumstellar material ejected by KPD 0005+5106 earlier in its evolution.