Search

Observations of optical flares from AT2022tsd (the ‘Tasmanian Devil’) show that they have durations on the timescale of minutes, occur over a period of months, are highly energetic, are probably nonthermal and have supernova luminosities.

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.

Observations of SN 2021yfj reveal that its progenitor is a massive star stripped down to its O/Si/S core, which remarkably continued to expel vast quantities of silicon-, sulfur-, and argon-rich material before the explosion, informing us that current theories for how stars evolve are too narrow.

A few missing photons in Fermi Gamma-ray Space Telescope observations lead to robust neutron star mass measurements in eclipsing millisecond pulsar binaries, ruling out an ultra-massive pulsar in the original Black Widow system.

By day 1,041 after explosion, SN Ia-CSM 2018evt had produced an estimated 0.01 solar masses of dust in the cold, dense shell behind the supernova ejecta–circumstellar medium interaction, ranking it as one of the most prolific dust-producing supernovae ever recorded.

Using ultraviolet data as well as a comprehensive set of further multiwavelength observations of the supernova 2023ixf, a reliable bolometric light curve is derived that indicates the heating nature of the early emission.

Archival images of the progenitor system of supernova SN 2011fe are so sensitive that the presence of luminous red giants or most helium stars is directly ruled out.

Superluminous supernova SN 2017egm has a complex light curve that is well modelled by successive collisions of a shockwave with dense circumstellar shells ejected by its massive progenitor star during the pair-instability pulsation stage. Such a scenario might be responsible for providing a power source for superluminous supernovae in general.

Analysis of a set of 1,863 bursts from the repeating source FRB 20201124A provides evidence of a complicated magnetized site within about an astronomical unit from the source in a barred galaxy.

The early stages of a lensed supernova at redshift 3 are found in images taken by the Hubble Space Telescope, with observations beginning from around 5.8 hours after the explosion.

Modelling the spectra and light curve of supernova SN 2006aj shows that it had a much smaller explosion energy and ejected much less mass than other gamma-ray burst–supernovae, suggesting that it was produced by a star whose initial mass was only ∼20 solar masses, and which left behind a neutron star, rather than a black hole.

An individual star at z = 1.49 is gravitationally lensed and highly magnified by a foreground galaxy cluster. Fluctuations in the star’s emission provide insight on the mass function of intracluster stars, compact objects and the presence of dark-matter subhaloes.

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.

Type II supernova explosions are common, but our understanding of such events is not complete. Such an event was observed just three hours after the explosion started, providing important information about the early stages.

A mass-loss event 40 days before the explosion of the type IIn supernova SN 2010mc has been detected; the outburst indicates that there is a causal relation between explosive mass-loss events seen in some massive stars before their explosion and the onset of the supernova explosion.

S. R. Kulkarni and colleagues report the discovery of a mysterious optical transient called M85 OT2006-1 in the outskirts of the lenticular galaxy Messier 85 in the Virgo Cluster. Brighter than novae and fainter than supernovae, it is unlikely to be a giant eruption from a luminous blue variable star because no such star is known to be there, but a possible origin is a stellar merger.

The JWST, with the aid of gravitational lensing, confirms the extreme distance of an ultra-faint galaxy at a redshift of 9.79, showing it to have a luminosity typical of the sources responsible for cosmic reionization and highly compact and complex morphology.

Observations of the supernova SN 2019hgp, identified about a day after its explosion, show that it occurred within a nebula of carbon, oxygen and neon, and was probably the explosion of a massive WC/WO star.

Supernovae are thought to arise through one of two processes. Type Ib/c and type II supernovae are produced when the cores of massive, short-lived stars undergo gravitational core collapse and eject a few solar masses. Type Ia supernovae are thought to form by the thermonuclear detonation of a carbon-oxygen white dwarf. Here a faint type Ib supernova, SN 2005E, is reported that seems not to have had a core-collapse origin, but perhaps arose from a low-mass, old progenitor, probably a helium-accreting white dwarf in a binary.

Extremely massive stars with initial masses of more than 140 solar masses end their lives when pressure-supporting photons turn into electron–positron pairs, leading to a violent contraction that triggers a nuclear explosion, unbinding the star in a pair-instability supernova. Here, the mass of the exploding core of supernova SN 2007bi is estimated at around 100 solar masses, in which case theory unambiguously predicts a pair-instability supernova. Further observations are well fitted by models of pair-instability supernovae.

Two unusual transient events, discovered by Hubble behind a strong-lensing galaxy cluster, can be explained as separate eruptions of a luminous blue variable star or a recurrent nova, or as an unrelated pair of stellar microlensing events.

Electron-capture supernovae are thought to come from progenitors with a narrow range of masses, and thus they are rare. Here the authors present six indicators of an electron-capture supernova origin, and find that supernova 2018zd fulfils all six criteria.

The discovery of a newly born type IIb supernova reveals a rapid brightening at optical wavelengths that corresponds to the shock-breakout phase of the explosion.

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.

Observations of an event (several energetic eruptions leading to a terminal explosion that is surprisingly hydrogen-rich) with the spectrum of a supernova do not match with other observations of supernovae.

The peculiar Type Ib supernova SN 2006jc is spatially coincident with a bright optical transient that occurred in 2004. An outburst (similar to that of a luminous blue variable star) of a Wolf–Rayet star could be invoked for the transient, but this would be the first observational evidence of such a phenomenon. Alternatively a massive binary system composed of an LBV which erupted in 2004, and a Wolf–Rayet star exploding as SN 2006jc, could explain the observations.

The explosion of a type Ia supernova could be triggered either by accretion from a companion—which should be indicated by brightening caused by interaction of supernova ejecta with the companion—or by a merger with a white dwarf or other small star; here observations by the Kepler mission of three type Ia supernovae reveal no such brightening, leading to the conclusion that they were triggered by a merger.

The detection of strong emission lines in an early-time spectrum of type IIb supernova SN 2013cu reveals Wolf–Rayet-like wind signatures, suggesting that the supernova’s progenitor may have been a Wolf–Rayet star with a wind dominated by helium and nitrogen, with traces of hydrogen.