SN Ares: A Strongly Lensed Type IIb Supernova at z=1.276 with a Predicted 70-Year Time Delay

@misc{larison2026ares,
  title = {{SN Ares: A Strongly Lensed Type IIb Supernova at $\mathbfz=1.276$ with a Predicted 70-Year Time Delay}},
  author = {Conor Larison and Justin D. R. Pierel and Matthew Siebert and Tom Resseguier and Lukas J. Furtak and Masamune Oguri and Gavin S. Farley and Hollis B. Akins and Yoshihisa Asada and Rachel Bezanson and Maruša Bradač and Gabriel Brammer and John Chisholm and Dan Coe and Pratika Dayal and Henry C. Ferguson and Steven L. Finkelstein and Seiji Fujimoto and Tomokazu Kiyota and Anton M. Koekemoer and Vasily Kokorev and Minami Nakane and Masami Ouchi and Richard Pan and Casey Papovich and Johan Richard and Luke Robbins and Fengwu Sun and Kana Takechi and Tommaso Treu and Chris Willott and Hiroto Yanagisawa and Abdurro'uf and Joseph F. V. Allingham and Ricardo O. Amorín and Franz E. Bauer and Larry Bradley and Mateusz Bronikowski and Christopher J. Conselice and David A. Coulter and James M. DerKacy and José M. Diego and Eiichi Egami and Andreas L. Faisst and Ori D. Fox and Brenda L. Frye and Yoshinobu Fudamoto and Mauro González-Otero and Massimo Griggio and Nimish P. Hathi and Tiger Yu-Yang Hsiao and Saurabh W. Jha and Y. Jiménez-Teja and Jeyhan S. Kartaltepe and Gourav Khullar and Zachary G. Lane and Paulo A. A. Lopes and Ray A. Lucas and Georgios E. Magdis and Matteo Messa},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.33161},
  eprint = {2610.33161},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.33161},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - SN Ares: A Strongly Lensed Type IIb Supernova at z=1.276 with a Predicted 70-Year Time Delay
AU  - Conor Larison
AU  - Justin D. R. Pierel
AU  - Matthew Siebert
AU  - Tom Resseguier
AU  - Lukas J. Furtak
AU  - Masamune Oguri
AU  - Gavin S. Farley
AU  - Hollis B. Akins
AU  - Yoshihisa Asada
AU  - Rachel Bezanson
AU  - Maruša Bradač
AU  - Gabriel Brammer
AU  - John Chisholm
AU  - Dan Coe
AU  - Pratika Dayal
AU  - Henry C. Ferguson
AU  - Steven L. Finkelstein
AU  - Seiji Fujimoto
AU  - Tomokazu Kiyota
AU  - Anton M. Koekemoer
AU  - Vasily Kokorev
AU  - Minami Nakane
AU  - Masami Ouchi
AU  - Richard Pan
AU  - Casey Papovich
AU  - Johan Richard
AU  - Luke Robbins
AU  - Fengwu Sun
AU  - Kana Takechi
AU  - Tommaso Treu
AU  - Chris Willott
AU  - Hiroto Yanagisawa
AU  - Abdurro'uf
AU  - Joseph F. V. Allingham
AU  - Ricardo O. Amorín
AU  - Franz E. Bauer
AU  - Larry Bradley
AU  - Mateusz Bronikowski
AU  - Christopher J. Conselice
AU  - David A. Coulter
AU  - James M. DerKacy
AU  - José M. Diego
AU  - Eiichi Egami
AU  - Andreas L. Faisst
AU  - Ori D. Fox
AU  - Brenda L. Frye
AU  - Yoshinobu Fudamoto
AU  - Mauro González-Otero
AU  - Massimo Griggio
AU  - Nimish P. Hathi
AU  - Tiger Yu-Yang Hsiao
AU  - Saurabh W. Jha
AU  - Y. Jiménez-Teja
AU  - Jeyhan S. Kartaltepe
AU  - Gourav Khullar
AU  - Zachary G. Lane
AU  - Paulo A. A. Lopes
AU  - Ray A. Lucas
AU  - Georgios E. Magdis
AU  - Matteo Messa
PY  - 2026
DA  - 2026/10/23
PB  - arXiv
DO  - 10.48550/arxiv.2610.33161
UR  - https://arxiv.org/abs/2610.33161
AB  - We present the discovery of supernova (SN) Ares, a strongly lensed supernova at z_spec=1.276±0.002 in a massive, triply imaged host galaxy behind the MACS J0308.9+2645 galaxy cluster. JWST/NIRSpec spectroscopy spanning the rest-frame optical to NIR of Ares reveals helium features at 5876 mathringA, 7065 mathringA, and 10830 mathringA, as well as Hα and Paβ. A comparison to local core-collapse SN spectra and light curves leads to a classification of SN Ares as a Type IIb supernova, the highest-redshift member of its class spectroscopically identified. A comparison to local SN IIb light curves provides a phase estimate for the spectrum of 34_−9^+10 rest-frame days post-radioactive peak, providing a unique view into a high-redshift stripped-envelope supernova in its late-photospheric evolution. A lens model of the cluster constructed using recent JWST data indicates that SN Ares is the first image to arrive and will reappear in two future images near the center of the cluster plane in ≳ 70 years, with predicted magnifications of ∼5× and ∼1.5×. Planned JWST/NIRSpec Multi-Object Spectroscopy of the cluster will allow for more detailed modeling of the lensed system for tighter constraints on the time delay and magnifications, as well as a template spectrum at the location of SN Ares.
ER  -