Friday, 28 February 2014

Habitable planet discovery in the APS Top 10 of 2013

Each year the American Physical Society (APS) looks back at the headlines from all around the world to see which physics stories grabbed the most attention. And guess what - one of the stories from our own University of Hertfordshire astrophysicists made it into the APS top 10 Physics Newsmakers of 2013!

Artist's impression of the Gliese 667C system
Credit:ESO/M. Kornmesser
In June 2013, an international team of astronomers led by Mikko Tuomi, from the University’s Centre for Astrophysics Research (CAR) and Guillem Anglada-Escude, University of Goettingen, Germany, found a nearby star which has a record-breaking three super-Earths lying in the habitable zone where liquid water could exist!

New observations of the star, known as Gliese 667C, were combined with existing data to reveal a system with at least six planets. Three of these planets were confirmed to be super-Earths — planets more massive than Earth, but less massive than planets like Uranus or Neptune.

And even more exciting, these three super-Earths were found to be within their star’s habitable zone - a thin shell around a star in which water may be present in liquid form if conditions are right and making them possible candidates to support life.

This was the first time that three such planets had been spotted orbiting in this zone in the same star system!

As Mikko said: “Finding three low-mass planets in the star’s habitable zone is very exciting!”

And so does the APS!!

Tuesday, 18 February 2014

Asteroid hurtles past Earth

Guest blog by Dr Mark Gallaway, Bayfordbury Observatory

For those of you who may have been alarmed to see the fiery image of the “potentially hazardous” asteroid, known as 2000 EM26, on The Guardian website, you will be pleased to hear that this 270 metre-wide rock passed safely by beyond the orbit of the moon today – just as predicted by astronomers.
Asteroid 2000 EM26 orbit diagram. Image from Wikimedia Commons courtesy of NASA/JPL
Although 2000 EM26 is a much larger asteroid than two of our more recent asteroid encounters, it does not pose any hazard to the Earth.  Almost exactly a year ago, we tracked asteroid 2012DA14 from our observatory as it made a very close pass to the Earth in February 2013.  And, during that same week, a much smaller object unexpectedly entered the atmosphere over Russia causing a window-breaking sonic boom before breaking up.

At the University of Hertfordshire’s Bayfordbury Observatory, we keep an eye on these large rocks as part of an on-going programme to monitor ‘Near Earth Objects’ (NEO).

Monday, 10 February 2014

Filming suranga tunnel systems in India

Guest blog: Dr Darren Crook, School of Life and Medical Sciences

Abu Jaffer-Ullah and Adam Jones-LLoyd from the University of Hertfordshire’s Digital Media team in action filming in India
Over the last few weeks, myself and my fellow researcher Sudhir Tripathi, have been tracked across India by a film crew - Abu Jaffer-Ullah and Adam Jones-LLoyd from the University’s Digital Media team.

We are putting together an hour long documentary on our research into suranga tunnel systems which are found mainly in the foothills of the Western Ghats of India in southern Karnataka and northern Kerala. These suranga are used by local farmers for both irrigation and drinking water.

Our filming activity was closely followed with great interest by an Indian water journalist, Shree Padre - who also collaborated with me in giving a talk to the Alike School run by the Sri Sathya Sai Loka Seva Trust which contains some of southern India’s brightest students.

It was good to work with Shree Padre as he was able to translate our story into some of the local languages, like Kannada, which meant that our story was told in a number of local newspapers on the 16th and 17th January.

Further collaborations with Dr Suthakar Isaac of St. Johns College, Palayamkottai (a Bat expert) and Dr Ravindranath Aithala (a Snake expert) allowed us to learn more about the fauna that live in or near to suranga so that we can better understand their conservation value as a new habitat.

During our time there, we also talked with the Varanashi Research Foundation to learn more about how suranga fit into broader systems of farming and water harvesting strategies.

The full length documentary is currently being produced and we hope that it may be ready for release in about a year’s time.

Thursday, 6 February 2014

Red sky day and night….on an extreme brown dwarf

Guest blog by Federico Marocco, Centre for Astrophysics Research

Red sky at night, shepherd's delight. Red sky in the morning, shepherd's warning”. We have all heard this old saying, it first appeared in the Bible in the Gospel of Matthew, used at sunrise and sunset to indicate the changing weather.
Artist’s impression of ULAS J222711-004547. This newly discovered brown dwarf is characterized by an unusually thick layer of clouds, made of mineral dust. These thick clouds give ULAS J222711-004547 its extremely red colour, distinguishing it from “normal” brown dwarfs.
Picture credit: Neil J Cook, Centre for Astrophysics Research, University of Hertfordshire

A red sky suggests an atmosphere loaded with dust and moisture particles. If the morning skies are red, it is because clear skies to the east permit the sun to light the undersides of moisture-bearing clouds coming in from the west.

Conversely, in order to see red clouds in the evening, sunlight must have a clear path from the west in order to illuminate moisture-bearing clouds moving off to the east. However, there are places with very different atmospheres where the sky is always red. This is the case of the recently discovered brown dwarf  known as ULAS J222711-004547.

Brown dwarfs are intermediate in mass between “normal” stars, like our Sun, and giant planets, like Jupiter and Saturn - too big to be considered as planets, yet unable to fuse hydrogen in their cores like stars.  Sometimes described as failed stars, they do not have an internal source of energy – so they are cold and very faint, and keep on cooling over time.

This particular object caught our attention for its extremely red appearance compared to “normal” brown dwarfs. Further observations with the Very Large Telescope (Chile) and the use of an innovative data analysis technique have shown that the reason for its peculiarity is the presence of a very thick layer of clouds in the upper atmosphere of the brown dwarf.

Not only have we been able to infer the clouds’ presence but we’ve also been able to estimate the size of the dust grains in the clouds – which are made mostly of mineral dust, like enstatite and corundum.

The atmosphere observed in this brown dwarf is hotter than the giant planets of our Solar System (like Jupiter and Saturn) with water vapour, methane and probably some ammonia but it is dominated by clay-sized mineral particles.

Getting a good understanding of how such an extreme atmosphere works will help us to better understand the range of atmospheres that can exist.

The paper, “The extremely red L dwarf ULAS J222711−004547 - dominated by dust, is published in the Monthly Notices of the Royal Astronomical Society by Oxford University Press.