Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Illustration of a brown dwarf

A rapidly spinning brown dwarf (pictured, artist’s impression) tends to have narrow atmospheric bands; the faster the spin, the thinner the bands. Credit: NASA/JPL-Caltech

Astronomy and astrophysics

Dim stars that have failed at fusion are masters of spin

Three brown dwarfs whirl on their axes at a dizzying rate that might be close to the celestial speed limit for these bodies.

Astronomers have caught three brown dwarfs spinning at the fastest rates ever recorded for these objects, which are sometimes described as ‘failed stars’.

Brown dwarfs are celestial objects with masses that fall between those of large, Jupiter-like planets and the smallest ordinary stars. They are cooler and dimmer than ordinary stars because they are too small to sustain long-term nuclear fusion.

Megan Tannock at the University of Western Ontario in London, Canada, and her collaborators analysed nearly 80 brown dwarfs with regular variations in their brightness and light spectrum. Such variations are produced when brighter spots on the stars’ surfaces come in and out of view as the stars rotate. Measuring the period of such variations gives an accurate estimate of how fast a star is spinning.

The authors found that 3 of the brown dwarfs had record-short rotation periods, ranging from 1 hour and 5 minutes to 1 hour and 14 minutes. The similarity between the periods suggests that the objects might be moving at close to a maximum speed limit, beyond which they would break apart.

More Research Highlights...

Light micrograph of a human egg cell during fertilisation

As a human egg cell is fertilized, two chromosome-containing cellular structures (dotted circles, centre) merge into one — a process that often goes wrong. Credit: Pascal Goetgheluck/Science Photo Library

Developmental biology

The error-prone step at the heart of making an embryo

High-resolution imaging shows why the union between two sets of chromosomes goes awry as least as often as not.
Satellite image of broken iceberg B-44.

Dark water borders chunks of iceberg broken off a West Antarctica glacier. The melting of the region’s ice sheet could allow the bedrock to rise, sloughing water into the ocean. Credit: NASA

Climate change

Antarctic rocks on the rebound could raise sea level much more than expected

When the ice covering the west of the continent disappears, the bedrock could rise up and shove extra water into the ocean.
Monteverde Cloud Forest Preserve, Costa Rica

Mist wafts through the trees at the Monteverde Cloud Forest Biological Preserve in Costa Rica. Cloud forests around the world are threatened by development, wood collection and climate change. Credit: Stefano Paterna/Alamy

Conservation biology

Forests that float in the clouds are drifting away

Tropical cloud forests are safe havens for a vast range of creatures and plants, but they are under siege around the globe.
Aerial photograph of beef cattle standing at the Texana Feeders feedlot in Floresville, Texas

Large-scale facilities such as this feedlot in Floresville, Texas, help to meet the global appetite for beef and other red meat, which remains strong despite the growing consumption of chicken and fish. Credit: Daniel Acker/Bloomberg/Getty


Meat lovers worldwide pay climate little heed

People are eating more poultry and fish — but they’re not giving up their hamburgers.
Midshipmen at dining table eat in formation, CIRCA 1900

Midshipmen in the United States in around 1900. A study found that body-mass index, a gauge of obesity, has increased with the generations during the twentieth century. Credit: Buyenlarge/Getty


A century of US data documents obesity’s racially skewed rise

An analysis also finds that obesity is common at a much younger age among people born in the early 1980s than those born in the late 1950s.
Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing


Quick links