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arXiv · 2511.17884

A New FU Orionis Accretion Outburst in the W5 HII Region

Lynne A. Hillenbrand·Matthew J. Graham·Mansi M. Kasliwal·Josiah Purdum·Jesper Sollerman·Adolfo S. Carvalho·Michael A. Kuhn·Roger Smith·Michael C. B. Ashley·Nicholas Earley·Russ R. Laher·Tracy X. Chen
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Abstract

We announce a recently detected outburst that is currently only a few months old, and probably of FU Orionis type. The progenitor to the outburst was an emission-line, flat-spectrum SED young stellar object located in the W5 region, though somewhat outside the main star formation action. We present optical, near-infrared, and mid-infrared lightcurves that illustrate the quiescent state of [KAG2008] 13656 and its subsequent$\Delta r \approx -4$ mag and $\Delta J\approx -3$ mag outburst over $\sim$75 days in late-2025. Follow-up optical and near-infrared spectroscopy confirms the expected features from an FU Ori disk and outflow.

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Lynne A. Hillenbrand, Matthew J. Graham, Mansi M. Kasliwal, Josiah Purdum, Jesper Sollerman, Adolfo S. Carvalho, Michael A. Kuhn, Roger Smith, Michael C. B. Ashley, Nicholas Earley, Russ R. Laher, Tracy X. Chen. 2025-11-22. A New FU Orionis Accretion Outburst in the W5 HII Region. https://arxiv.org/abs/2511.17884

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