Type Ibn supernovae (SNe) are a mysterious class of transients whose spectra exhibit persistently narrow HeI lines, and whose bolometric light curves are typically fast evolving and overluminous at peak relative to standard Type Ibc SNe. We explore the interaction scenario of such Type Ibn SNe by performing radiation-hydrodynamics and radiative-transfer calculations. We find that standard-energy helium-star explosions within dense wind-like circumstellar material (CSM) can reach on day timescales a peak luminosity of a few 10^44 erg/s, reminiscent of exceptional events like AT2018cow. Similar interactions but with weaker winds can lead to Type Ibc SNe with double-peak light curves and peak luminosities in the range ~10^42.2 to ~10^43 erg/s. In contrast, the narrow spectral lines and modest peak luminosities of most Type Ibn SNe are suggestive of a low-energy explosion in an initially <~5 Msun helium star, most likely arising from interacting binaries, and colliding with a massive helium-rich, probably ejecta-like, CSM at ~10^15 cm. Nonlocal thermodynamic equilibrium radiative-transfer simulations of a slow-moving dense shell born out and powered by the interaction compare favorably to Type Ibn SNe like 2006jc, 2011hw, or 2018bcc at late times and suggest a composition made of about 50% helium, a solar metallicity, and a total ejecta/CSM mass of 1-2Msun. A lower fractional helium abundance leads to weak or absent HeI lines and thus excludes more massive configurations for observed Type Ibn SNe. Further, the dominance of FeII emission below 5500A seen in Type Ibn SNe at late times is not predicted at low metallicity. Hence, despite their promising properties, Type Ibn SNe from pulsational-pair instability in very massive stars, which requires low metallicity, have probably not yet been observed.
Massive stars exploding in a He-rich circumstellar medium - VII. The metamorphosis of ASASSN-15ed from a narrow line Type Ibn to a normal Type Ib Supernova
Nested, asymmetric H-He circumstellar shells in the Type Icn/Ibn SN 2024abvb
European Southern Observatory（欧洲南方天文台）；Cardiff University（卡迪夫大学）；University of Ferrara（费拉拉大学）；INFN, Sezione di Ferrara（意大利国家核物理研究所费拉拉分部）；INAF, Osservatorio Astronomico d’Abruzzo（意大利国家天体物理研究所阿布鲁佐天文台）；National Central University（中央大学）；University College Dublin（都柏林大学学院）；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究研究所）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所）
A modeling perspective on the diversity of red-supergiant stars exploding within circumstellar material
Institut d’Astrophysique de Paris, CNRS-Sorbonne Université（巴黎天体物理研究所，CNRS-索邦大学）；Cahill Center for Astrophysics, California Institute of Technology（加州理工学院卡希尔天体物理学中心）
JWST Reveals Large Reservoirs of Dust and Ongoing Circumstellar Interaction in SN Ibn/Icn 2023xgo over a Year Post-Explosion
University of California, Santa Cruz（加州大学圣克鲁兹分校）；National Astronomical Research Institute of Thailand（泰国国家天文研究所）；SETI Institute（SETI研究所）；The University of Melbourne（墨尔本大学）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；INAF, Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）；Space Telescope Science Institute（太空望远镜科学研究所）；Stockholm University（斯德哥尔摩大学）；Northwestern University（西北大学）
Massive stars exploding in a He-rich circumstellar medium XII. SN 2024acyl: A fast, linearly declining Type Ibn supernova with early flash-ionisation features
Yunnan Observatories, Chinese Academy of Sciences（中国科学院云南天文台）；International Centre of Supernovae, Yunnan Key Laboratory（超新星国际中心，云南省重点实验室）；INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；Department of Astronomy, Kyoto University（京都大学天文学系）；South-Western Institute for Astronomy Research, Yunnan University（云南大学西南天文研究所）；Yunnan Key Laboratory of Survey Science, Yunnan University（云南大学云南省测绘科学重点实验室）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Electronic Science and Engineering, Chongqing University of Posts and Telecommunications（重庆邮电大学电子科学与工程学院）；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；INAF - Osservatorio Astronomico d’Abruzzo（意大利国家天体物理研究所阿布鲁佐天文台）
SN 2024acyl 是一种快速、线性衰减的 Type Ibn 超新星，具有早期闪光电离特征，其光谱和光变曲线特征支持由抛射物与 CSM 交互驱动的 SN 模型。
Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密森天体物理中心）；University of California, Santa Cruz（加州大学圣克鲁兹分校）；The University of Melbourne（墨尔本大学）；Massachusetts Institute of Technology（麻省理工学院）；University of Hawaii（夏威夷大学）；University of Illinois at Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）
SN 2023fyq: direct detection of a Type Ibn supernova progenitor and its multi-wavelength environmental constraints
University of Chinese Academy of Sciences（中国科学院大学）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天体物理研究所）；School of Space and Earth Sciences, Beihang University（北京航空航天大学空间与地球科学学院）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）；Department of Astronomy, School of Physics, Peking Unversity（北京大学物理学院天文学系）
Late-time H/He-poor circumstellar interaction in the type-Ic supernova SN 2021ocs: an exposed oxygen-magnesium layer and extreme stripping of the progenitor
The first radio view of a type Ibn supernova in SN 2023fyq: Understanding the mass-loss history in the last decade before the explosion
University of Virginia（弗吉尼亚大学）；National Radio Astronomy Observatory（国家射电天文台）；University of California, Berkeley（加州大学伯克利分校）；California Institute of Technology（加州理工学院）；The Observatories of the Carnegie Institution for Science（卡内基科学研究所天文台）；Northwestern University（西北大学）；The University of Tokyo（东京大学）
SN 2024abvb: a Type Ibn/Icn supernova with evidence of helium and an extreme offset from its host galaxy
Cardiff University（卡迪夫大学）；INAF-Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；European Southern Observatory（欧洲南方天文台）；Universidad de Tarapacá（塔拉帕卡大学）；University of Arizona（亚利桑那大学）；University of Hawaii at Manoa（夏威夷大学马诺阿分校）；National Central University（中央大学）；Las Cumbres Observatory（激光观测站）；University of California, Santa Barbara（加州大学圣塔芭芭拉分校）
SN 2024abvb是一种具有氦证据的Ibn/Icn型超新星，其与宿主星系存在极端偏移，光谱和光度特征显示其独特的演化模式。
Supernovae interacting with Si and S-rich circumstellar matter from double white dwarf mergers
National Astronomical Observatory of Japan, National Institutes of Natural Sciences（日本国立天文台，日本国立科学研究所）；Graduate Institute for Advanced Studies, SOKENDAI（综合研究大学院大学）；School of Physics and Astronomy, Monash University（蒙纳士大学物理与天文学学院）；International Center of Supernovae (ICESUN), Yunnan Key Laboratory of Supernova Research, Yunnan Observatories, Chinese Academy of Sciences（中国科学院云南天文台超新星国际研究中心（ICESUN），云南省超新星研究重点实验室）
The flash-ionised SN Ibn 2025kzr: H-free CSM formed during a precursor outburst 55 days prior to explosion
DTU Space, Technical University of Denmark（丹麦技术大学空间中心）；South African Astronomical Observatory（南非天文台）；Department of Astronomy, University of Cape Town（开普敦大学天文学系）；Department of Physics, University of the Free State（自由邦大学物理系）；Department of Physics, Stellenbosch University（斯坦伦布什大学物理系）；Department of Astrophysics/IMAPP, Radboud University（拉德堡德大学天体物理学系/IMAPP）；The Inter-University Institute for Data Intensive Astronomy, University of Cape Town（开普敦大学跨大学数据密集型天文研究所）；Department of Particle Physics and Astrophysics, Weizmann Institute of Science（魏茨曼科学研究所粒子物理与天体物理系）
Signatures of Circumstellar Interaction in the Type IIL Supernova ASASSN-15oz
富氢、核心坍缩的超新星通常分为四类：IIP、IIL、IIn和IIb。一般来说，与星周物质的相互作用只被认为是IIn型超新星。然而，最近对IIP和IIL超新星的流体动力学建模需要星周物质来重现它们早期的光变曲线。在这种情况下，IIL超新星在爆炸前经历了大量的质量损失。我们在ASASSN-15 oz上测试了这一假设，这是一颗IIL型超新星。随着X射线、紫外线、光学、红外线和无线电的广泛跟踪，我们提出了我们对相互作用迹象的搜索，以及由它们的检测所指示的质量损失历史。我们发现的证据表明，短暂的激烈的质量损失之前，爆炸的光变曲线建模，相当于在1.5 M $_{\odot}$的材料在1800 R $_{\odot}$的祖先。我们还检测到超新星的无线电，表明质量损失率$10^{-6}-10^{-7}$ M $_{\odot}$年$^{-1}$之前的极端质量损失期。我们未能在X射线中探测到这颗超新星，在紫外线、可见光和近红外线中也没有窄的发射谱线，这些都与这幅图并不矛盾，并在$<10^{-4}$ M $_{\odot}$ yr $^{-1}$的极端周期之外设定了质量损失率的上限。本文强调了收集更多II型超新星的全面数据的重要性，以便详细建模的祖星和超新星，可以阐明他们的质量损失历史和包络结构，从而告知恒星演化模型。
Type Ib supernovae are bluer than Type Ic supernovae
Max Planck Institute for Astrophysics（马普天体物理研究所）；European Southern Observatory（欧洲南方天文台）；Technische Universität München（慕尼黑工业大学）；Seoul National University（首尔大学）；Tel Aviv University（特拉维夫大学）；Michigan State University（密歇根州立大学）
