An amateur astronomer has discovered a comet that could have come from a distant star.

ESO’s VISTA telescope reveals a remarkable image of the Large Magellanic Cloud, one of our nearest galactic neighbours. VISTA has been surveying this galaxy and its sibling the Small Magellanic Cloud, as well as their surroundings, in unprecedented detail. This survey allows astronomers to observe a large number of stars, opening up new opportunities to study stellar evolution, galactic dynamics, and variable stars.

Nature, Published online: 12 September 2019; doi:10.1038/d41586-019-02729-8

The age of a giant star is one of its most difficult traits to measure, but a new method tells all.

Portal origin URL: NASA’s Hubble Finds Water Vapor on Habitable-Zone Exoplanet for 1st TimePortal origin nid: 451609Published: Wednesday, September 11, 2019 - 13:05Featured (stick to top of list): noPortal text teaser: With data from the Hubble Space Telescope, water vapor has been detected in the atmosphere of a super-Earth with habitable temperatures.Portal image: exoplanet K2-18b illustrationScience Categories: Universe

The local expansion rate of the Universe is parametrized by the Hubble constant, , the ratio between recession velocity and distance. Different techniques lead to inconsistent estimates of . Observations of Type Ia supernovae (SNe) can be used to measure , but this requires an external calibrator to convert relative distances to absolute ones. We use the angular diameter distance to strong gravitational lenses as a suitable calibrator, which is only weakly sensitive to cosmological assumptions. We determine the angular diameter distances to two gravitational lenses, and megaparsec, at redshifts and . Using these absolute distances to calibrate 740 previously measured relative distances to SNe, we measure the Hubble constant to be kilometers per second per megaparsec.

Astronomers discover water in the atmosphere of a "habitable" planet orbiting a distant star.

Nature, Published online: 11 September 2019; doi:10.1038/s41586-019-1556-x

Galaxy GSN 069 has unprecedented eruptions of X-ray light every nine hours, which indicate fast transitions between cold and warm states and may shed light on black hole accretion.

Nature, Published online: 11 September 2019; doi:10.1038/d41586-019-02652-y

A galaxy has been seen producing strong, regular bursts of X-rays that recur on timescales of hours. The eruptions imply that the matter flowing onto the galaxy’s central black hole undergoes repeated restructuring.

Nature, Published online: 11 September 2019; doi:10.1038/s41586-019-1532-5

Radio observations show a bipolar bubble structure of size 140 parsecs by 430 parsecs both above and below the Galactic Centre.

Nature, Published online: 11 September 2019; doi:10.1038/d41586-019-02721-2

The exoplanet is just twice the diameter of Earth, and could potentially host life.

Nature, Published online: 11 September 2019; doi:10.1038/d41586-019-02726-x

First major result from South Africa’s pioneering MeerKAT radiotelescope reveals remnants of energetic explosions at Galaxy’s centre.

Portal origin URL: New Models Suggest Titan Lakes Are Explosion CratersPortal origin nid: 451516Published: Monday, September 9, 2019 - 06:58Featured (stick to top of list): noPortal text teaser: A new theory, based on radar data from NASA's Cassini mission, proposes that some of Titan's lakes formed when pockets of nitrogen blew out basins that filled with methane.Portal image: Artist's concept of a lake at the north pole of Saturn's moon Titan.Science Categories: Solar System

Video Length: 3:15

Neptune will be at opposition in September, providing sky watchers and astronomers the opportunity to observe this planet that is invisible to the naked eye, but that scientists would love to see more clearly.

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Nature, Published online: 06 September 2019; doi:10.1038/d41586-019-02695-1

The Event Horizon Telescope team has won US$3-million. Plus: the lost half of one of the most important fossils of all time has been virtually restored and scientists see the first hint that body’s ‘biological age’ can be reversed.

Nature, Published online: 07 September 2019; doi:10.1038/d41586-019-02697-z

The Chandrayaan-2 mission would have been the first to land near the lunar south pole.

The team that took the first ever image of a black hole announces plans to take a "razor sharp" full-colour video of the one at the centre of our galaxy.

Nature, Published online: 04 September 2019; doi:10.1038/s41586-019-1510-y

Observations of highly redshifted broad absorption lines of helium and hydrogen atoms provide unambiguous evidence of fast infalling gas that is merging into an accretion disk around a black hole.

Nature, Published online: 05 September 2019; doi:10.1038/d41586-019-02659-5

The Event Horizon Telescope team wins a Breakthrough Prize — one of six awards covering physics, the life sciences and mathematics.