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arXiv · 2502.08931

Deep Optical Images of the Ejecta Nebula Around the Wolf-Rayet Star WR 8 (HD 62910)

Robert A. Fesen·Daniel Patnaude·Wei-Hao Wang·You-Hua Chu·Jason Sun·Manuel C. Peitsch·Martin Pugh·Scott Garrod·Michael Selby·Alex Woronow
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Abstract

We report the results of deep H$\alpha$ and [O III] images of the bright WN6/WC4 Wolf-Rayet star WR~8 (HD~62910). These data show considerably more surrounding nebulosity than seen in prior imaging. The brighter portions of the nebula span $\simeq6'$ in diameter and exhibit considerable fine-scale structure including numerous emission clumps and bright head-tail like features presumably due to the effects of the WR star's stellar winds. Due to the overlap of a relatively bright band of unrelated foreground diffuse interstellar H$\alpha$ emission, WR~8's nebula is best viewed via its [O III] emission. A faint $9' \times 13'$ diffuse outer nebulosity is detected surrounding the nebula's main ring of emission. Comparison of the nebula's optical structure with that seen in WISE 22 $\mu$m data shows a similarly clumpy structure but in a better defined emission shell of thermal continuum from dust. The infrared shell is coincident with the nebula's southern [O III] emissions but is mainly seen in the fainter outer portions of the northern [O III] emission clumps. It is this greater radial distance of dust emission in the nebula's northern areas that leads to a striking off-center position of the WR star in the IR shell.

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Robert A. Fesen, Daniel Patnaude, Wei-Hao Wang, You-Hua Chu, Jason Sun, Manuel C. Peitsch, Martin Pugh, Scott Garrod, Michael Selby, Alex Woronow. 2025-02-13. Deep Optical Images of the Ejecta Nebula Around the Wolf-Rayet Star WR 8 (HD 62910). https://arxiv.org/abs/2502.08931

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