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The Einstein Probe has discovered a fast X-ray transient, EP240414a, associated with a broad-lined type Ic supernova. Its unusually soft spectrum and weak jet add to the diversity of stellar deaths and suggest a previously unknown Wolf–Rayet star explosion mechanism.

A stripped-envelope supernova, SN 2022jli, shows 12.4-day periodic undulations during the declining light curve, and narrow Hα emission is detected in late-time spectra with concordant periodic velocity shifts.

The death of massive stars has traditionally been discovered by explosive events in the gamma-ray band. Liu et al. show that the sensitive wide-field monitor on board Einstein Probe can reveal a weak soft-X-ray signal much earlier than gamma rays.

A possible kilonova associated with a nearby, long-duration gamma-ray burst suggests that gamma-ray bursts with long and complex light curves can be spawned from the merger of two compact objects, contrary to the established gamma-ray burst paradigm.

A multi-frequency observing campaign of the γ-ray burst GRB 190114C reveals a broadband double-peaked spectral energy distribution, and the teraelectronvolt emission could be attributed to inverse Compton scattering.

A double neutron star merger gave rise to the gravitational-wave event GW 170817, with counterpart electromagnetic radiation in the optical and gamma-ray spectra. Polarization measurements of the optical emission reveal a lanthanide-rich macronova.

A report of the optical discovery and follow-up observations of the type Ic supernova SN 2006aj associated with X-ray flash XRF 060218. SN 2006aj was intrinsically less luminous than the gamma-ray burst (GRB)–supernovae connection, but more luminous than many supernovae not accompanied by a GRB.

Long-duration γ-ray bursts (GRBs), thought to result from the explosions of certain massive stars, are bright enough that some of them should be observable out to redshifts of z > 20. So far, the highest redshift measured for any object has been z = 6.96, for a Lyman-α emitting galaxy. Here, and in an accompanying paper, GRB 090423 is reported to lie at a redshift of z ≈ 8.2, implying that massive stars were being produced and dying as GRBs approximately 620 million years after the Big Bang.

Late-time optical and near-infrared observations of the binary neutron star merger GW170817 are at odds with kilonova models but match a Gaussian-structured relativistic jet, which would have launched a high-luminosity short gamma-ray burst to an aligned observer.

Observations from the JWST of the second brightest GRB ever detected, GRB 230307A, indicate that it belongs to the class of long-duration GRBs resulting from compact object mergers, with the decay of lanthanides powering the longlasting optical and infrared emission.

Reanalysis of the spectra associated with the merger of two neutron stars identifies strontium, spectroscopically establishing the origin of the heavy elements created by rapid neutron capture and proving that neutron stars comprise neutron-rich matter.

An unusual ultraviolet compact object associated with a dusty starburst has been observed at a redshift of about 7.2, with a luminosity that falls between that of quasars and galaxies, possibly in transition between the two. 

This paper presents evidence for dynamical interactions in the very dense regions in the core of galaxies causing two compact objects, such as neutron stars and black holes, to merge, leading to a gamma-ray burst.

Circularly polarized light is unexpectedly detected in the afterglow of γ-ray burst GRB 121024A measured 0.15 days after the burst, and is shown to be intrinsic to the afterglow and unlikely to be produced by dust scattering or plasma propagation effects.

γ-ray bursts are more concentrated in the very brightest regions of their host galaxies than are supernovae — in addition, the host galaxies of the γ-ray bursts are significantly fainter and more irregular than the hosts of the supernovae.

A new class of ultra-long-duration γ-ray bursts (GRBs) has recently been suggested, with durations in excess of 10,000 seconds, and now a supernova (SN 2011kl) has been found to be associated with the ultra-long-duration GRB 111209A, allowing a physical understanding of the nature of ultra-long-duration GRBs.

Multi-epoch observations of a supernova associated with a γ-ray burst reveal spectral features at extremely high expansion velocities within the first day after the burst, indicative of a choked jet.

The astronomical event GW170817, detected in gravitational and electromagnetic waves, is used to determine the expansion rate of the Universe, which is consistent with and independent of existing measurements.

Observations of the transient associated with the gravitational-wave event GW170817 and γ-ray burst GRB 170817A reveal a bright kilonova with fast-moving ejecta, including lanthanides synthesized by rapid neutron capture.