SN 2020bio: A Double-peaked, H-poor Type IIb Supernova with Evidence of Circumstellar Interaction
C. Pellegrino, D. Hiramatsu, I. Arcavi, D. A. Howell, K. A. Bostroem, P. J. Brown, J. Burke, N. Elias-Rosa, K. Itagaki, H. Kaneda, C. McCully, M. Modjaz, E. Pad… 展开作者
C. Pellegrino, D. Hiramatsu, I. Arcavi, D. A. Howell, K. A. Bostroem, P. J. Brown, J. Burke, N. Elias-Rosa, K. Itagaki, H. Kaneda, C. McCully, M. Modjaz, E. Padilla Gonzalez, T. A. Pritchard, N. Yesmin
We present photometric and spectroscopic observations of SN 2020bio, a double-peaked Type IIb supernova (SN) discovered within a day of explosion, primarily obtained by Las Cumbres Observatory and Swift. SN 2020bio displays a rapid and long-lasting initial decline throughout the first week of its light curve, similarly to other well-studied Type IIb SNe. This early-time emission is thought to originate from the cooling of the extended outer hydrogen-rich (H-rich) envelope of the progenitor star that is shock heated by the SN explosion. We compare SN 2020bio to a sample of other double-peaked Type IIb SNe in order to investigate its progenitor properties. Analytical model fits to the early-time emission give progenitor radius ($\approx$ 100--1500 $R_\odot$) and H-rich envelope mass ($\approx$ 0.01--0.5 $M_\odot$) estimates that are consistent with other Type IIb SNe. However, SN 2020bio displays several peculiarities, including: (1) weak H spectral features indicating a greater amount of mass loss than other Type IIb progenitors; (2) an underluminous secondary light-curve peak that implies a small amount of synthesized $^{56}$Ni ($M_{\text{Ni}}$ $\approx$ 0.02 $M_\odot$); and (3) low-luminosity nebular [O I] and interaction-powered nebular features. These observations are more consistent with a lower-mass progenitor ($M_{\text{ZAMS}} \approx$ 12 $M_\odot$) that was stripped of most of its H-rich envelope before exploding. This study adds to the growing diversity in the observed properties of Type IIb SNe and their progenitors.
SN 2024iss: A Double-peaked Type IIb Supernova with Evidence of Circumstellar Interaction
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文学与空间科学学院）；Las Cumbres Observatory（拉斯坎布拉观测站）；University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；Università degli Studi di Padova（帕多瓦大学）；INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布里埃拉天文台）；Department of Astronomy, University of California, Berkeley（加州大学伯克利分校天文学系）；Yunnan Observatories, Chinese Academy of Sciences（中国科学院云南天文台）；International Centre of Supernovae, Yunnan Key Laboratory（国际超新星研究中心（云南省重点实验室））；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）；Department of Physics, Tsinghua University（清华大学物理系）
Constraints on the Progenitor of SN 2016gkg From Its Shock-Cooling Light Curve
SN 2016 gkg是一颗在超新星爆发后不久被发现的IIb型超新星。与其他几个有早期数据的IIb型事件一样，SN 2016 gkg显示出双峰的光变曲线，第一个峰值与低质量扩展祖包层的冷却有关。我们提出了前所未有的intrinight-cadence多波段测光覆盖SN 2016 gkg的第一个光变曲线峰值从拉斯坎布雷斯天文台全球望远镜网络，小行星地球撞击最后警报系统，斯威夫特卫星和各种业余操作的望远镜。将这些数据与激波冷却模型进行拟合，可以得到原始星系半径约为25-140个太阳半径，扩展包层中的物质质量约为2-30 x 10^-2（取决于模型和假设的主星系灭绝）。我们的半径估计是大致一致的价值观独立得出（在其他作品）从HST成像的祖星。然而，冲击冷却模型半径是在爆炸前成像所指示的值的下端。流体动力学模拟可以精确的祖参数推导出的冲击冷却发射和测试的分析模型。
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。
SN 2024iss: A Multi-Wavelength Exposé of a Type IIb Supernova with an Early-Time Ultraviolet Spectrum and Shock Breakout Constraints
University of North Carolina at Chapel Hill（北卡罗来纳大学教堂山分校）；California Institute of Technology（加州理工学院）；University of Illinois at Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；Institut d’Astrophysique de Paris, CNRS-Sorbonne Université（巴黎天体物理研究所，CNRS-索邦大学）
