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A new ultraluminous X-ray source has been discovered in M 31, whose variability and associated bright, compact radio emission identify it as a stellar-mass black hole accreting close to the Eddington limit.

A massive starburst galaxy with 100 billion solar masses of gas is identified at a redshift of 6.34; a ‘maximum starburst’ converts the gas into stars at a rate more than 2,000 times that of the Milky Way.

Massive galaxies in the early Universe have been shown to be forming stars at high rates. Probing the properties of individual star-forming regions is beyond the resolution and sensitivity of existing telescopes. Here, however, observations are reported of the galaxy SMMJ2135–0102 at redshift z=2.3259, which has been gravitationally magnified by a factor of 32 by a galaxy cluster lens in the foreground. The physics underlying star formation here is similar to that in local galaxies, but the energetics are very different.

An observation of a rare merger of two massive submillimetre bright galaxies that is forming stars at an unexpectedly high rate of 2,000 solar masses a year shows that such mergers can indeed form the most massive elliptical galaxies by about redshift 1.5.

In June 2022, the IXPE satellite observed a shock passing through the jet of active galaxy Markarian 421. The rotation of the X-ray-polarized radiation over a 5-day period revealed that the jet contains a helical magnetic field.

Molecular emission lines originating in Titan’s relatively unexplored upper mesosphere and thermosphere reveal a strong prograde jet that reaches speeds of 340 m s^–1 at 1,000 km altitude.

Pluto’s haze could have a major icy component created by the condensation of organic molecules such as C₄H₂. This is different from Titan whose haze, despite a similar atmospheric composition, is mostly macromolecular aggregates. Triton’s haze, instead, should be dominated by ices, particularly C₂H₄.

The millimetre image of the Centaurus A nucleus by the Event Horizon Telescope reveals a highly collimated, asymmetrically edge-brightened jet. The source’s event horizon shadow should be visible at terahertz frequencies, consistent with the universal scale invariance of black holes.

The spectral variability of the blazar CTA 102 during a recent extreme outburst could be explained by a twisted, inhomogeneous jet containing regions of different orientations that vary in time.

The detection of ~20 ppb of phosphine in Venus clouds by observations in the millimetre-wavelength range from JCMT and ALMA is puzzling, because according to our knowledge of Venus, no phosphine should be there. As the most plausible formation paths do not work, the source could be unknown chemical processes—maybe even life?

The cores of most large galaxies are thought to harbour super massive black holes. Sagittarius A*, the compact source of radio, infrared and x-ray emission at the centre of the Milky Way, is the closest example of this phenomenon. This paper reports observations that set a limit less than the expected apparent size of the event horizon of the presumed black hole, suggesting that the bulk of Sgr A* emission may not be centred on the black hole, but arises in the surrounding accretion flow.

It is widely accepted that strong and variable radiation detected over all accessible energy bands in a number of active galaxies arises from a relativistic, Doppler-boosted jet pointing close to our line of sight. However, the size of the emitting zone and the location of this region relative to the central supermassive black hole are poorly understood. Here, the coincidence of a γ-ray flare with a dramatic change of optical polarization angle is reported, providing evidence for co-spatiality of optical and γ-ray emission regions and indicating a highly ordered jet magnetic field.