Author Archives: Chris North


About Chris North

Dr Chris North is the Ogden Science Lecturer in Cardiff University's School of Physics and Astronomy. He also holds an STFC Public Engagement Fellowship entitled "The Dawn of Gravitational Wave Astronomy". Chris is also an astronomy researcher by training, focusing most recently on the Herschel Space Observatory.

Pythagorean Astronomy: the GLEAM Survey


The GLEAM Survey

We’ve got a lot of news items to discuss this month. In the outer Solar System, Edward Gomez and I discuss the Cassini spacecraft, which has made its final major orbital manoeuvre, and the Juno spacecraft, which has had a few issues getting into its main science orbit. Further from home, we’ve got the first “official” star names from the International Astronomical Union, and the discovery of the roundest known star.

Our main guest this month is Dr Natasha Hurley-Walker, based at the International Centre for Radio Astronomy Research (ICRAR) at Curtin University. Natasha works on the Murchison Widefield Array, and has produced GLEAM: an all-sky image of the sky at radio wavelengths at very high resolution and in a wide range of radio “colours”, or wavelengths. This gives us a better understanding of some of the most energetic processed taking place in the centres of nearby galaxies, but the end goal is somewhat further afield. Natasha tells me all about the MWA, the GLEAM project, and even how you can view it – on the interactive GLEAMoscope site (or using the GLEAM Android app)

Originally broadcast on 28th November 2016 as part of Pythagoras’ Trousers on Radio Cardiff.

Pythagorean-Astronomy: ExoMars and Galaxies

A lot has happened this month – ESA got a spacecraft into orbit around Mars, but sadly lost the Schiaparelli lander, China launched two new taikonauts to their space station, and the Swarm mission uncovered details from Earth depths. Edward Gomez and I discussed these, and more, this month (though before the full nature of the status of the Schiaparelli lander were available).

In other astronomy news, a scientific paper hit the headlines claiming to have worked out how many galaxies there are in the observable Universe. Cardiff colleague Professor Steve Eales told me quite what he thought of this latest result…

Originally broadcast on 24th October 2016 as part of Pythagoras’ Trousers on Radio Cardiff.

Pythagorean Astronomy: Rosetta and OSIRIS-REx

Rosetta_at_comet_67P_landscape_1280This month sees the start of one mission and the end of another. NASA’s OSIRIS-REx mission launched at the start of the month to go and study asteroid Bennu, and even bring back a sample to Earth.

Meanwhile, the end of the month sees the finale of ESA’s Rosetta mission, which has spent two years studying comet 67P/Churyumov-Gerasimenko. With stunning images accompanied by fascinating results from other instruments, not to mention the plucky little Philae lander, Rossetta has been one of the most exciting missions of recent years.

This month, the Open University’s Professor Monica Grady tells me about comets, asteroids, and these two exciting missions.

Originally broadcast on 26th September 2016 as part of Pythagoras’ Trousers on Radio Cardiff.

[Cross posted from our Cardiff University School of Physics and Astronomy engagement site]

Pythagorean Astronomy: Mission Juno


Artist’s Impression of a Juno and Jupiter. Credit: NASA

In July 2016 NASA’s Juno spacecraft completed its five year journey to the planet Jupiter. On board is a suite of instruments and experiments that will provide exquisite insight into the history of our Solar System’s largest planet.

The process of Jupiter’s formation is a long-standing mystery that planetary scientists have been trying to answer for decades. As the University of Leicester’s Dr Leigh Fletcher explains, Juno will make careful measurements of Jupiter’s gravitational field and yield crucial information about its interior.

Originally broadcast on 28th July 2016 as part of Pythagoras’ Trousers on Radio Cardiff.

Pythagorean Astronomy: the Origins of Black Holes

GRO J1655-40 is the second so-called 'microquasar' discovered in our Galaxy. Microquasars are black holes of about the same mass as a star. They behave as scaled-down versions of much more massive black holes that are at the cores of extremely active galaxies, called quasars. Astronomers have known about the existence of stellar-mass black holes since the early 1970s. Their masses can range from 3.5 to approximately 15 times the mass of our Sun. Using Hubble data, astronomers were able to describe the black-hole system. The companion star had apparently survived the original supernova explosion that created the black hole. It is an ageing star that completes an orbit around the black hole every 2.6 days. It is being slowly devoured by the black hole. Blowtorch-like jets (shown in blue) are streaming away from the black-hole system at 90% of the speed of light.

Artist’s Impression of a black hole in a binary star system. Credit: ESA/Hubble

[cross-posted from Cardiff Physics Outreach blog]

On 15th June 2016 the LIGO collaboration released more detections of gravitational waves. As with the first detection, announced back in February, these gravitational waves were emitted by pairs of black holes, spiralling together and merging,

But of course, those black holes need to come from somewhere, and in this case it’s thought to be the deaths of some of the most massive stars in the Universe. To understand more about the deaths of massive stars, and the formation of black holes, I talked to Professor Stephen Smartt, from Queen’s University Belfast, who’s been on the hunt for black holes.

Originally broadcast on 30th June 2016 as part of Pythagoras’ Trousers on Radio Cardiff.

Pythagorean Astronomy: New worlds


Artist’s impression of the Kepler spacecraft

This month’s focus is on two different stories, but both involving the same spacecraft: Kepler. Edward Gomez and I discuss a result from the outer edge of our Solar System, regarding the icy world that goes by the catchy name of “2007 OR10”. By combining information from the Kepler Spacecraft, now in the second phase of its mission with a partially-functioning spacecraft, with results from the Herschel Space Observatory, astronomers have made a new estimate of its size. Continue reading

Breakthrough Starshot

Breakthrough StarshotEarlier this week we heard the announcement of a new project from the “Breakthrough Initiatives”. The group is led by Yuri Milner, a Russian entrepreneur apparently named after Yuri Gagarin, along with Stephen Hawking and Mark Zuckerberg, and with support of an advisory panel of astronomers, theoretical physicists, space scientists, engineers and business leaders. The new initiative, Breakthrough Starshot, has the goal of sending a fleet of tiny spacecraft to the nearest star system. It gathered a fair bit of attention, at least for 24 hours—BBC Radio Wales even asked me to chat to them about it on Good Evening Wales. Continue reading

Pythagorean Astronomy: To Mars – and Beyond!

[Cross-posted from the Cardiff Physics Engagement blog]

March 2016 saw the launch of the first part of Europe’s two-part mission to Mars. The mission, called ExoMars, comprises the “Trace Gas Orbiter” – the part that’s just launched – and a large rover, which launches in 2018. The orbiter will sniff the atmosphere to test for evidence of past  – or maybe even present – life. Elsewhere in the world of astronomy, this month has also seen the discovery a cluster of “monster stars”, and the most distant galaxy ever seen. I chatted to Edward Gomez and Tim Davis, a relatively new arrival here in Cardiff, about these discoveries.

Originally broadcast on 31st March 2016 as part of Pythagoras’ Trousers on Radio Cardiff.

Could we get rid of leap years?

It probably didn’t escape your notice that yesterday was 29th February – a date that comes round but once every 4 years. The reason for having leap years is explained in detail by Phil Plait on his Bad Astronomy blog (which is actually quite good). It’s essentially because the Earth’s rotation and the Earth’s orbit around the Sun aren’t quite in sync. Although a year is usually 365 days long, the Earth actually takes around 365.25 to get to the same place in space around its orbit. (It’s not exactly 365.25, and Phil Plait explains the details so I’ll defer to him.) Continue reading

Pythagorean Astronomy: The Voice of Einstein

[Cross-posted from the Cardiff Physics Engagement site]

Unless you’ve been under a bush for the past month, you can’t have missed what could be described the news of the Century – the first direct detection of gravitational waves. This month, I speak to Edward Gomez about what this discovery means, and catch up with some of the gravitational physicists here in Cardiff, Andrew Williamson, Frank Ohme and Lionel London. They tell me quite how sensitive the LIGO instruments are, and how gravitational waves are the voice of Einstein.

Originally broadcast on 25th February 2016 as part of Pythagoras’ Trousers on Radio Cardiff.