Nestled in the greenery of Co. Offaly is one of the most important pieces of scientific technology Ireland has to its name. The quiet gardens of Birr Castle are home to one of the over 50 antennae of the European LOFAR (Low Frequency Array) interferometry network. The Irish (I-LOFAR) telescope is part of a large network of radio telescopes stretching from Poland to the Netherlands. These telescopes work in unison; by using the combination of smaller antennae like one large antenna they make valuable contributions to the field of astrophysics. As one of the many cogs in the LOFAR machine, Trinity researchers are hard at work trying to unravel more of the complex mysteries of our universe.
The I-LOFAR site had its beginnings as Trinity’s own Rosse Solar Terrestrial Observatory. Built in 2010 for the School of Physics, it soon became clear that the site of the observatory offered a lot of scope for other projects. The low radio frequency interference in Birr allowed for the collection of particularly clear data, and so the road to I-LOFAR began. In much more distant history, the Birr Castle site was also home to the most innovative telescope of the 19th century. The Leviathan optical telescope was built in 1845 by the 3rd Earl of Rosse and retained the title of the world’s largest telescope until 1917. The telescope, which has stood on the same grounds as I-LOFAR for over 170 years, has a peculiar canon-like appearance and is protected by high walls. The Leviathan was rebuilt and refurbished in the 90s after it became clear that the site was an important part of the cultural and scientific heritage. A modern mirror was added to the rebuilt Leviathan so as to allow for its continued relevance as technology improved.
“As one of many cogs in the LOFAR machine, Trinity researchers are hard at work trying to unravel more of the complex mysteries of our universe.”
In 2017, continuing the strong astronomical tradition on the Birr Castle grounds, building began for a project for the newest generation of star gazers. The telescope, which was built by a team of undergraduate scientists from Trinity and other Irish universities including University College Dublin (UCD), Dublin City University (DCU), Technological University Dublin (TU Dublin) and the National University of Ireland, Galway (NUI Galway), officially opened in July 2017. The build cost around €1.4 million but, to the untrained eye, the specialist radio telescope might not appear to be anything special. The site contains a large cluster of antennae placed on top of a labyrinth of wire mesh. This doesn’t look at all like the traditional optical telescope we imagine one uses to peruse the night sky, and yet it too allows us to learn about the universe around us.
The telescope operates by using the wire mesh to reflect radio waves into the copper antennae, similar to how a tv satellite dish works. It uses a carefully designed array of these detectors, of both low band and high band to collect information on a range of wavelengths from many different celestial objects, near and far. Radio telescopes collect information about light waves that are outside the visible light spectrum for humans. Many celestial bodies emit radiation in the form of radio waves and detecting these can alert us to the presence of undiscovered planets and galaxies, which we would not be able to pick out using optical methods. These radio waves can even be used to image distant objects and give us an idea of what they look like though we can’t actually “see” them in the visible spectrum.
Since I-LOFAR’s opening their team have been hard at work. In April 2017 the Birr interferometer was used to detect a stellar flare explosion in red dwarf star “CN Leo” 75 trillion kilometers away. The team has also investigated the effects of solar eruptions on particles in the sun’s outermost, gaseous layer, the corona. I-LOFAR has recently started to do more public outreach having opened an education centre in 2018, to inform the public on the history of the observatory and the work being carried out there. Only time will tell if I-LOFAR will have a lasting legacy on the field of astronomy like its precursor Leviathan. One thing is certain: generations of Irish scientists will continue to have their sights firmly fixed on the stars for years to come.
Stargazing in October:
Even without a €1.4 million radio telescope at your disposal, there’s plenty to be seen as an amateur astronomer this coming October. October 5 brings NASA’s International Observe the Moon Night when the moon will be in its first quarter and, weather permitting, it will be possible to clearly see a striking semicircular lunar phase. Those interested in participating can register to be lunar observers on the NASA website and follow along on social media.
Also visible in the October night sky will be the constellation of Pegasus and the spiral galaxy of Andromeda. The former can be seen as the horse shaped constellation, while the latter appears as a dim fuzzy “star”. Andromeda is the furthest object that can be seen with the naked eye, and if viewed with a pair of binoculars you can clearly see the elliptical shape of the galaxy.
When heading out to have a look at the stars, light pollution should be avoided at all costs. Head out to rural areas or higher ground away from tall buildings. Given the inactive nature of stargazing, wrapping up in warm clothes is a must. There are plenty of useful apps and websites to keep you updated on the night sky or alternatively it is also possible to download and a print good old fashioned star map online. The International Space Station (ISS) also regularly updates their website with times the station may be visible in its orbit. By using this tool it is possible to see a timetable of when the ISS crosses the night sky at any given location.
Alternatively, when the weather isn’t suitable or escaping the city’s light pollution is not possible, apps such as Google Star Maps can be a great way to explore the vastness of space and familiarise yourself with its many wonders without even having to leave the comfort of your home.