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Astronomers identify imprints of chemical evolution in rare carbon and oxygen isotopes of 32 nearby red dwarf stars. Metal-rich stars exhibit lower isotope ratios than the Sun, suggesting substantial chemical enrichment in the past few billion years.

Hot Jupiters are a class of extrasolar planet that orbit their parent stars at very short distances and are expected to be tidally locked, which can lead to a large temperature difference between the dayside and the nightside. Here, the day–night contrast of the transiting extrasolar planet HD 188733b is 'mapped' using infrared observations; the data are consistent with the nightside hemisphere being entirely black, with the dayside flux dominating the optical phase curve.

Seven small planets whose surfaces could harbour liquid water have been spotted around a nearby dwarf star. If such a configuration is common in planetary systems, our Galaxy could be teeming with Earth-like planets. See Letter p.456

If the orbital velocity of an extrasolar planet could be determined, the masses of both the planet and its host star could be calculated using Newton's law of gravity. Here, high-dispersion ground-based spectroscopy of a transit of the extrasolar planet HD 209458b is reported. This allowed the radial component of the planet's orbital velocity to be calculated, and thus the masses of star and planet. Moreover, a strong wind flowing from the irradiated dayside to the non-irradiated nightside of the planet is suggested.

Observations of ¹³CO in the atmosphere of a young, accreting super-Jupiter indicate a ¹³C-rich atmosphere, which is attributed to the accretion of carbon from ices enriched in ¹³C through fractionation.

Near-infrared spectroscopic observations of the young extrasolar planet β Pictoris b indicate that it spins significantly faster than any planet in the Solar System, in line with the extrapolation of the known trend in spin velocity with planet mass.

The detection of carbon monoxide absorption in the spectrum of the extrasolar planet τ Boötis b, and its tracing of the change in the radial velocity of the planet, demonstrates that atmospheric characterization is possible for non-transiting planets.

For most binary stars, the theoretical and observed precession rates are in agreement, but the observed precession rate for the DI Herculis system is a factor of four slower than the theoretical rate, a disagreement that once was interpreted as evidence for a failure of general relativity. Here, both stars of DI Herculis are reported to rotate with their spin axes nearly perpendicular to the orbital axis, an observation that leads to the reconciliation of the theoretical and observed precession rates.