The FU Ori outburst of PR Ori B

@misc{pena2026outburst,
  title = {{The FU Ori outburst of PR Ori B}},
  author = {Carlos Contreras Pena and Zsofia Nagy and Gregory Herczeg and Jeong-Eun Lee and Agnes Kospal and Peter Abraham and Doug Johnstone and Bo Reipurth and Chul-Hwan Kim and Hyun-Il Sung and Yihan Li and Jiaze Wang and Rui Wu and Foteini Lykou and Mizna Ashraf and John Bally and Fernando Cruz-Saenz de Miera and Min Fang and Eleonora Fiorellino and Christoffer Fremling and Teresa Giannini and Jessy Jose and Mansi Kasliwal and Maria Kun and Ho-Gyu Lee and Michal Siwak and Mate Szilagyi and Sung-Yong Yoon and Zsofia Bora and Borbala Cseh and Agoston Horti-David and Zsoka Horvath and Andras Peter Joo and Csilla Kalup and Klara Lelkes and Andras Pal and Zsolt Regaly and Krisztian Sarneczky and Balint Seli and Adam Sodor and Norton O. Szabo and Zsofia Szabo and Robert Szakats and Nora Takacs and Miguel Vioque},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.09722},
  eprint = {2609.09722},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.09722},
}

TY  - UNPB
TI  - The FU Ori outburst of PR Ori B
AU  - Carlos Contreras Pena
AU  - Zsofia Nagy
AU  - Gregory Herczeg
AU  - Jeong-Eun Lee
AU  - Agnes Kospal
AU  - Peter Abraham
AU  - Doug Johnstone
AU  - Bo Reipurth
AU  - Chul-Hwan Kim
AU  - Hyun-Il Sung
AU  - Yihan Li
AU  - Jiaze Wang
AU  - Rui Wu
AU  - Foteini Lykou
AU  - Mizna Ashraf
AU  - John Bally
AU  - Fernando Cruz-Saenz de Miera
AU  - Min Fang
AU  - Eleonora Fiorellino
AU  - Christoffer Fremling
AU  - Teresa Giannini
AU  - Jessy Jose
AU  - Mansi Kasliwal
AU  - Maria Kun
AU  - Ho-Gyu Lee
AU  - Michal Siwak
AU  - Mate Szilagyi
AU  - Sung-Yong Yoon
AU  - Zsofia Bora
AU  - Borbala Cseh
AU  - Agoston Horti-David
AU  - Zsoka Horvath
AU  - Andras Peter Joo
AU  - Csilla Kalup
AU  - Klara Lelkes
AU  - Andras Pal
AU  - Zsolt Regaly
AU  - Krisztian Sarneczky
AU  - Balint Seli
AU  - Adam Sodor
AU  - Norton O. Szabo
AU  - Zsofia Szabo
AU  - Robert Szakats
AU  - Nora Takacs
AU  - Miguel Vioque
PY  - 2026
DA  - 2026/09/09
PB  - arXiv
DO  - 10.48550/arxiv.2609.09722
UR  - https://arxiv.org/abs/2609.09722
AB  - We report the discovery of a nearby FU Ori-type outburst (FUor), PR Ori B, in the L1641 cluster of the Orion star-forming region. The high-amplitude variability was first identified in the NEOWISE (3-5 μm) photometry of the unresolved PR Ori binary system. Long-term, resolved optical photometric monitoring demonstrates that PR Ori B is the driver of a ΔG=5mag outburst, while PR Ori A has remained constant over the last 20 years. The near-IR spectrum of PR Ori B changes from a late K-type spectral type during quiescence to a viscously heated disk during outburst, including deep absorption in ^12CO and H_2O bands. The optical spectrum also exhibits features that are commonly associated with FUors, including P Cygni profiles in Na I D lines and absorption in the Ca II infrared triplet. The luminosity of the outburst (L_acc∼30--40 L_⊙) is similar to that commonly observed in FUors. The comparison of Spitzer/IRS and VLT/VISIR spectroscopy shows some evidence of silicate crystallisation during the outburst. PR Ori B is one of the closest and brightest FUors discovered over the last few years, only one magnitude fainter than the archetype of the class FU Ori. The proximity and brightness will allow for future high angular resolution observations to probe the physics of the inner disk and to evaluate changes in the disk due to the increased luminosity.
ER  -