When nuclear fuel in the core of a massive star with a zero-age main-sequence mass $M_{\rm ZAMS} \gtrsim 8M_\odot$ is exhausted, the central part of the iron or magnesium core collapses and forms a neutron star or a black hole. At the same time, the material above the collapsing core is rapidly ejected, leading to a stripped-envelope supernova (SESN) explosion if the outer hydrogen envelope of the star was removed before its explosion. The envelope is presumably stripped either via strong stellar winds or due to mass transfer to a companion star in a close binary orbit. It is not clear which process is dominant, and whether different mechanisms are at work for different classes of SESNe; type IIb, Ib, and Ic SNe in order of increasing degree of envelope stripping. In this work, a new analysis of late-time nebular spectra of SESNe is presented, which is more sensitive to differences in the core structure than early-phase spectral analysis. The results show that the progenitors of SNe IIb and Ib are indistinguishable except for the residual amount of hydrogen envelope while the progenitors of SNe Ic are not only deficient in hydrogen and helium, but are also distinctly more massive than SNe IIb and Ib. These findings strongly suggest that more than one mechanism is responsible for the removal of the outer hydrogen envelope and the deeper helium layer, with the former most likely due to binary interaction, and the latter involving a mass-dependent process such as strong stellar winds or episodic pre-explosion mass ejection.
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
NLTE Spectral Modelling of the Nearby Stripped-Envelope Supernova 2024ehs
Stockholm University（斯德哥尔摩大学）；Max Planck Institute for Extraterrestrial Physics（马克斯·普朗克地外物理研究所）；California Institute of Technology（加州理工学院）；Weizmann Institute of Science（魏茨曼科学研究所）
The hydrogen-free circumstellar interaction in the Type Ib supernova 2021efd: A clue to the mechanism of the helium-layer stripping
University of Turku（图尔库大学）；Nordic Optical Telescope（北欧光学望远镜）；Aalto University（阿尔托大学）；National Astronomical Observatory of Japan, National Institutes of Natural Sciences（日本国立天文台，国立自然科学研究所）；Finnish Center of Astronomy with ESO (FINCA)（芬兰ESO天文学中心）；Aarhus University（奥胡斯大学）；Kyoto University（京都大学）；Zhejiang University（浙江大学）
Low-Luminosity Type IIP Supernovae from the Zwicky Transient Facility Census of the Local Universe. III: Hunting for electron-capture supernovae using nebular spectroscopy
California Institute of Technology（加州理工学院）；Stockholm University（斯德哥尔摩大学）；Weizmann Institute of Science（魏茨曼科学研究所）；NSF NOIRLab（美国国家光学-红外天文研究实验室）
Spectral Dataset of Stripped-Envelope Supernovae from the Tsinghua Supernova Group
Beijing Planetarium（北京天文馆）；Beijing Academy of Sciences and Technology（北京市科学技术研究院）；Department of Physics, Tsinghua University（清华大学物理系）；Yunnan Observatories, Chinese Academy of Sciences（中国科学院云南天文台）；International Centre of Supernovae, Yunnan Key Laboratory（云南省超新星国际研究中心）；Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences（中国科学院天体结构与演化重点实验室）；School of Physics and Information Engineering, Jiangsu Second Normal University（江苏第二师范学院物理与信息技术学院）
The Berkeley Sample of Stripped-Envelope Supernovae
我们提出了完整的样本的剥离信封超新星（SN）光谱观测的利克天文台超新星搜索（LOSS）合作在过去的三十年中：888光谱的302 SNe，652在这里首次公布，与384光谱（92 SNe）具有光度测定的阶段。在校正红移和银河系尘埃红化和重新评估每个SN的光谱分类后，我们构建了三个主要光谱亚型（IIb型，Ib型和Ic型）的平均光谱。我们比较了这个样本的谱线强度和宽度的测量结果与以前的结果，证实了在峰值亮度后的前30天内，Ic型SNe中O I λ7774的吸收比Ib或IIb型SNe更强，并且速度更快，尽管星云发射谱线的宽度在亚型之间是一致的。我们还强调了一些罕见的感兴趣的亚群的新观察。
Reconciling the Tension Between Light Curve Modeling of Type II Supernovae and Neutrino-Driven Core-Collapse Supernovae Models with Late-Phase Spectroscopy
SN 2022ngb: A faint, slowly evolving Type IIb supernova with a low-mass envelope
Yunnan Key Laboratory of Survey Science, Yunnan University（云南省测绘科学重点实验室，云南大学）；INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；Yunnan Observatories, Chinese Academy of Sciences (CAS)（中国科学院云南天文台）；International Centre of Supernovae, Yunnan Key Laboratory（超新星国际研究中心，云南省重点实验室）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（ICE，CSIC））；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；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）
SN 2022ngb是一颗低光度IIb型超新星，其前身星为中等质量、相对紧凑的剥离包层恒星，爆炸参数包括喷流质量、能量和放射性物质分布。
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）
A low mass, binary-stripped envelope for the Type IIb SN 2024abfo
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, Stellenbosch University（斯泰伦博斯大学物理系）；Department of Astrophysics/IMAPP, Radboud University（拉德堡德大学天体物理学/IMAPP系）；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）
SN 2024abfo是具有直接前身体检测的最暗淡IIb型超新星，其低质量氢包层可能由二元系统导致，光谱特征与SN 2008ax相似，但无双峰光变曲线。
我们提出了一个分析的507光谱的173剥离信封（SE）超新星（SNe）发现的非目标帕洛玛瞬态工厂（PTF）和中间PTF（iPTF）的调查。我们的样本包含55个IIb型SNe（SNe IIb），45个Ib型SNe（SNe Ib），56个Ic型SNe（SNe Ic）和17个Ib/c型SNe（SNe Ib/c）。我们通过测量He I $λ\lambda5876, 7065$和O I $\lambda7774$吸收线的伪等效宽度（pEW）和速度来比较SE SN亚型。与以前的工作一致，我们发现，SNe Ic显示更高的pEW和速度在O I $\lambda7774$相比，SNe IIb和Ib。He I $λ\lambda5876, 7065$谱线的pEW在最大光照后在SNe Ib和IIb中是相似的。在最大光照下，He I $λ\lambda5876, 7065$在SNe Ib中的速度高于SNe IIb。我们已经确定了SNe IIb和Ib中He I $\lambda7065$ pEW和O I $\lambda7774$速度之间的关系。这可以解释为爆炸时He含量的连续性。有人认为，SNe Ib和Ic具有相似的He含量，并且较低的混合可能是SNe Ic中隐藏He的原因。然而，我们的数据与这种混合假设相矛盾。如果假设SE SN亚型之间的其他爆炸参数不变，则在SNe Ic（$V_{\mathrm{m}}…
SN2017ckj: A linearly declining Type IIb supernova with a relatively massive hydrogen envelope
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）；University of Chinese Academy of Sciences（中国科学院大学）；INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（ICE，CSIC））；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）
SN 2024aecx: a fast-evolving Type IIb supernova with a prominent shock-cooling peak
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）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天文与天体物理研究所）；Aryabhatta Research Institute of Observational Sciences（阿亚巴塔观测科学研究所）；Mahatma Jyotiba Phule Rohilkhand University（马哈特马·乔蒂巴·普尔·罗希尔坎德大学）；Department of Physics, Royal Holloway, University of London（伦敦大学皇家霍洛威学院物理系）；National Astronomical Research Institute of Thailand（泰国国家天文研究所）；Institute of Astrophysics, Central China Normal University（华中师范大学天体物理研究所）；Education Research and Application Center, National Astronomical Data Center（国家天文数据中心教育研究与应用中心）；Key Laboratory of Quark and Lepton Physics (Central China Normal University), Ministry of Education（教育部夸克与轻子物理重点实验室（华中师范大学））；Millennium Institute of Astrophysics（天体物理千年研究所）；Department of Physics, Indian Institute of Technology Roorkee（印度理工学院卢尔基分校物理系）；Department of Physics, University of Warwick（华威大学物理系）；Department of Applied Optics and Photonics, University of Calcutta（加尔各答大学应用光学与光子学系）；Chinese Academy of Sciences South America Center for Astronomy (CASSACA), National Astronomical Observatories, CAS（中国科学院南美天文中心（CASSACA），中国科学院国家天文台）；Centre for Astrophysics Research, University of Hertfordshire（赫特福德大学天体物理学研究中心）
SN 2024aecx是一颗快速演化型IIb超新星，通过高频率观测揭示其冲击冷却峰值和双星前身系统特征。
