T. Brink

Tomography analysis of the intermediate-luminosity Type Iax SN 2024pxl

Barnabás Barna, Mridweeka Singh, Lindsey A. Kwok +90

We present an abundance tomography analysis of SN 2024pxl, an intermediate luminosity Type Iax supernova ( $M_{r} = - 16.82 \pm 0.19$ mag), with the most-detailed follow-up in the Type…

First Pre-peak Ultraviolet Spectrum of a Tidal Disruption Event: A Fast Outflow Revealed Prior to Maximum Light in TDE2025aarm

Erica Hammerstein, Ryan Chornock, Jean Somalwar +32

The tidal disruption and eventual accretion of a star by a massive black hole can lead to the launching of outflows and winds that encode important information about the tidal disr…

CHASE Spectral Survey I: Measuring Contamination in the Color-selected J-region Asymptotic Giant Branch Distance Indicator

Siyang Li, Alexei V. Filippenko, Arief Ahmad +11

The J-region asymptotic giant branch (JAGB) method for distance measurements uses the near uniform luminosity of carbon-rich AGB stars as a standard candle. Its application rests o…

SN 2026dix: a nearby, transitional Type IIb/Ib supernova consistent with a warm supergiant progenitor

Tamás Szalai, Schuyler D. Van Dyk, Dominik Bánhidi +20

Understanding the final evolution stages of (very) massive stars and their explosive outcomes, stripped-envelope supernovae (SESNe), represent a long-term challenge for astrophysic…

AT 2016blu: Accretion-Powered Outbursts in a Luminous Blue Variable and Compact Object Binary

Mojgan Aghakhanloo, Núria Torres-Albà, Nathan Smith +33

We present the first X-ray detection of the supernova (SN) impostor AT 2016blu in NGC 4559. AT 2016blu exhibited 27 detected quasiperiodic (~113 day) outbursts between 2012 and Jun…

JWST Spectroscopy of Type Ia Supernova 2025rbs from Maximum Light to the Nebular Phase

Lindsey A. Kwok, Stéphane Blondin, Adam A. Miller +53

We present JWST observations of the Type Ia supernova (SN Ia) 2025rbs ( $D =$ 14.5 Mpc) at +1, +23, and +84 days after B-band maximum, spanning peak light through a wavelength-depende…

JWST Spectra Indicate a Large Mass of Postshock Dust Formed by SN 2010jl

Nathan Smith, Melissa Shahbandeh, Ori D. Fox +22

We present new JWST mid-IR spectra and ground-based optical spectra of the lingering source at the position of SN 2010jl, which was a relatively nearby superluminous Type IIn super…

SN 2022erq: A Superluminous Thermonuclear Supernova with Escalating Preexplosion Mass Loss

Qian Zhai, Jujia Zhang, Xiaofeng Wang +51

We present a photometric and spectroscopic study of the superluminous Type Ia supernova SN 2022erq. Its early spectra, dominated by iron-group elements with weak intermediate-mass…

Ultraviolet to Infrared Spectroscopy of the Type Ibn SN 2023tsz Suggests a Lower-mass Progenitor

Sergiy S. Vasylyev, Griffin Hosseinzadeh, Luc Dessart +42

Type Ibn supernovae are stripped-envelope explosions whose spectra indicate interaction with dense, helium-rich and hydrogen-poor circumstellar material (CSM), making them importan…

In the Eye of the Storm: The Third Giant X-ray Outburst of the Extreme Changing-look AGN IC 3599

D. Grupe, S. Komossa, W. Zheng +10

We report the discovery and multiwavelength follow-up observations of a giant (factor >100) X-ray outburst of the exceptional changing-look active galactic nucleus (AGN) IC 3599. T…

X-rays breaking out of pre-explosion ejecta mark a supernova's first light

Weimin Yuan, Qiu-Ju Huang, Jin-Ping Zhu +130

Massive stars die as core-collapse supernovae, whose optical light emerges days after the implosion. Theory predicts that the initial collapse-driven shock, upon breaking through t…

JWST Observations of Calcium-Strong Transients: I. Complex Nebular He Emission in SN 2024uj

Saarah Hall, Lindsey A. Kwok, Aravind P. Ravi +29

We present the first JWST observations of a Calcium-Strong Transient (CaST), SN 2024uj, a rare class of supernovae (SNe) with observable properties that are consistent with both th…

SN 2019vxm: A luminous and long-lived Type IIn supernova with early flash-ionisation features

Y. -Z. Cai, A. Pastorello, T. J. Moriya +38

We present the photometric and spectroscopic analysis of the luminous and long-lasting Type IIn supernova (SN) 2019vxm. The SN reaches a peak V-band absolute magnitude of MV = -20.…

First Results from the LSST Shadow Survey: The Restless Luminous Blue Variable AT2017des in the Virgo-Cluster Galaxy, NGC4532

Conor L. Ransome, Bhagya M. Subrayan, David J. Sand +66

The Legacy Survey of Space and Time (LSST) will start in late-summer 2026, revolutionizing transient astronomy. Here, we present the Dark Energy Camera (DECam) Shadow Survey, which…

OQ~208: A New Fe~II Changing-look Active Galactic Nucleus and Implications for the Nature of the Changing-look Phenomenon

J. Wang, W. K. Zheng, D. W. Xu +5

In addition to the traditional hydrogen Balmer emission lines, here we extend the optical changing-look (CL) phenomenon occurring in some active galactic nuclei (AGNs) to the optic…

GRB 250424A: A Case Study of Energy Injection with Multiwavelength Observations

Yifang Liang, Yun Wang, WeiKang Zheng +61

We present a comprehensive multiwavelength analysis of the long-duration gamma-ray burst (GRB) 250424A. Our dataset spans from the prompt gamma-ray emission to late-time optical mo…

The pair-instability origin of supernova 2023vbw

Daichi Hiramatsu, Edo Berger, Daichi Tsuna +18

Stars in the initial and carbon-oxygen core mass ranges of $\sim 140 - 260$ and $50 - 130$ M $_{⊙}$ , respectively, with low metallicity are predicted to experience copious electron-pos…

SN2023ixf: ultraviolet-to-infrared radiative-transfer modeling of the nebular-phase evolution until 1000 days

Luc Dessart, Wynn V. Jacobson-Galan, K. Azalee Bostroem +6

We present non-local thermodynamic equilibrium radiative-transfer modeling of SN2023ixf during the nebular phase out to 1000d, using the same ejecta that matched its photospheric e…

JWST Nebular Spectroscopy of SN 2023qov: Circumstellar Dust Emission in a Normal Type Ia Supernova

Colin W. Macrie, Conor Larison, Huei Sears +43

We present panchromatic observations of the Type Ia supernova (SN Ia) 2023qov, ranging from $\sim$ 2 weeks before to $\sim$ 1 year after maximum light. JWST near- and mid-infrared sp…

SN2023ixf: Radiative-transfer modeling of the photospheric phase evolution from the ultraviolet to the infrared

Luc Dessart, Wynn V. Jacobson-Galan, K. Azalee Bostroem +4

SN2023ixf, a Type II supernova (SN) showing early signs of interaction with circumstellar material (CSM), has been observed with unprecedented detail across the electromagnetic spe…

Are "Changing-Look" Active Galactic Nuclei Special in the Coevolution of Supermassive Black Holes and their Hosts? II. The Case of Changing-Look Narrow-Line Seyfert 1 Galaxies

J. Wang, S. Jin, D. W. Xu +5

The evolutionary role of the so-called ``changing-look'' (CL) active galactic nucleus (AGN), which is characterized by spectral-type transitions within $\sim 10$ yr, has been sugges…

AT 2024wpp: the most luminous fast-evolving optical transient linked to the merger explosion of a black-hole binary

Jialian Liu, Bao Wang, Xiaofeng Wang +48

Fast blue optical transients (FBOTs) represent one of the most exotic astrophysical transients, exhibiting unusually strong emission across X-ray, optical, and radio wavelengths. T…

SN 2024igg: A Super-Chandrasekhar/03fg-like SN exhibiting C II-dominated spectra after explosion

Jialian Liu, Xiaofeng Wang, Liyang Chen +14

We present and analyze photometric and spectroscopic observations of the Type Ia supernova (SN Ia) 2024igg, another ``super-Chandrasekhar'' (or 03fg-like) SN whose strong C II $\la…