Time-domain astronomy articles from across Nature Portfolio

There are only a few 3+1-type stellar systems known. Here the authors show that TIC 120362137 is the most compact hierarchical quadruple star, with three stars revolving within an area smaller than Mercury’s orbit, while the fourth star orbits closer to them than Jupiter from our Sun.

High-energy X-ray reverberation has been observed in active galactic nuclei but remained undetected in stellar-mass black holes. Here, the authors show detection of Compton hump reverberation in an X-ray binary, supporting a unified accretion picture across black hole masses.

Black-hole masses are estimated from broad emission-line widths and luminosity. Here, the authors show that over decades the luminosity varies while line widths remain constant biasing mass estimates, but using narrow-line luminosity corrects this.

Long-period radio transients emit periodic radio pulses of unknown origin. The longest-lived source, GPM J1839−10, has a 21-min spin and 9-h orbit, resembling the more rapid white dwarf pulsars that are powered by binary interaction, potentially linking the classes.

The study introduces radio interferometric multiplexed spectroscopy (RIMS), a method designed to efficiently monitor the radio emissions of massive samples of stars. Applying it to LOFAR data, the authors identify stellar bursts, offering clues to possible star–planet magnetic interactions.

Black hole (BH) masses can be estimated from tidal disruption events (TDEs). Here, the authors show that AT 2018cqh, a TDE, exhibits unusual X-ray characteristics consistent with a TDE scenario involving an intermediate-mass BH.

Long-period transients are repeating radio pulses of mysterious origin with minute-to-hour periods. The longest-lived of these — GPM J1839–10 — is now shown to be a binary system and seemingly mirrors the more rapid white dwarf pulsars, in which interaction of a stellar remnant with a companion star generates powerful radio beams.

These two types of compact objects share several similarities, despite their different compositions. A short workshop in Spain brought communities together to share understanding of dense matter under extreme conditions.