Big weather on brown dwarf

SMALL PRINT:WE MAY HAVE had some blustery weather in Ireland this week, but it's small fry compared to apparent disturbances spotted on a "brown dwarf" in space by astronomers.

The findings jumped out during a project that’s looking at nearby brown dwarves – sub-stellar bodies that bridge the gap between small stars and giant planets.

Using an infra-red camera on a telescope in Chile, the astronomers captured images of the brown dwarf 2Mass 2139 and saw striking changes in brightness over the course of hours.

“We might be looking at a gigantic storm raging on this brown dwarf, perhaps a grander version of the Great Red Spot on Jupiter in our own solar system, or we may be seeing the hotter, deeper layers of its atmosphere through big holes in the cloud deck,” said study co-author Prof Ray Jayawardhana from the University of Toronto.

Elsewhere, astronomers announced a flurry of 50 newly discovered exoplanets, or planets that lie outside our own solar system, including 16 “super-Earths”.

One of the exoplanets, HD 85512 b, is estimated to be 3.6 times the mass of Earth and is at the edge of the “habitable zone” – a narrow region around a star in which water may be present in liquid form if conditions are right, according to a release from the European Southern Observatory.

“In the coming 10 to 20 years we should have the first list of potentially habitable planets in the Sun’s neighbourhood,” said Michel Mayor from the University of Geneva, who leads a team using the Harps spectrograph on the 3.6-metre telescope at ESO’s La Silla Observatory in Chile to hunt for exoplanets.

“Making such a list is essential before future experiments can search for possible spectroscopic signatures of life in the exoplanet atmospheres,” Mayor says.

– Claire O’Connell

When hello baby means goodbye testosterone

MEN IN stable relationships who become fathers experience a drop in testosterone following the birth of their child, according to a new study published online this week in the Proceedings of the National Academy of Sciences.

Such a hormonal dip is seen in some non-human species where males care for the young, and previous studies on humans had taken cross-sectional“snapshots” of testosterone levels in groups of men. But what’s different about this study is that it monitored hormonal changes longitudinally over time as single non-fathers become fathers in a stable relationship.

The researchers measured testosterone levels in a community-based cohort of 624 men living in or near Cebu City in the Philippines, “where it is common for fathers to be involved in day-to-day care of their children”, write the study authors, from Northwestern University in the US and the University of San Carlos in the Philippines.

They found that single men with no children who had high testosterone levels at baseline aged 21 were more likely to have become partnered fathers at follow-up over four years later.

And those who had become partnered fathers in that time had larger drops in waking and evening testosterone levels than the changes seen in single non-fathers at follow-up.

“Our findings suggest that human males have an evolved neuroendocrine architecture that is responsive to committed parenting, supporting a role of men as direct caregivers during hominin evolution,” write the authors.

– Claire O’Connell