28 June 2016

Royal Astronomical Society’s National Astronomy Meeting 2015 – report 4

By Kulvinder Singh Chadha

The Venue Cymru conference centre on Llandudno seafront, home of the Royal Astronomical Society's National Astronomy Meeting 2015. Image credit: Venue Cymru
The Venue Cymru conference centre on Llandudno seafront, home of the Royal Astronomical Society’s National Astronomy Meeting 2015. Image credit: Venue Cymru
Around 500 astronomers and space scientists gathered at Venue Cymru in Llandudno, Wales, from 5-9 July, for the Royal Astronomical Society National Astronomy Meeting 2015 (NAM2015, Cyfarfod Seryddiaeth Cenedlaethol 2015). The conference is the largest regular professional astronomy event in the UK and saw leading researchers from around the world presenting the latest work in a variety of fields. Science writer and editor Kulvinder Singh Chadha presents his fourth and final report from the last day of the event:

The two-hearted Sun beckons new ‘mini ice-age’
Like the enigmatic, eponymous character from Doctor Who our Sun may have two hearts. A new model of the Sun’s interior is producing predictions of its behaviour with unprecedented accuracy; predictions with interesting consequences for Earth. Professor Valentina Zharkova of Northumbria University presented results for a new model of the Sun’s interior dynamo in a talk at NAM2015.

Montage of images of solar activity between August 1991 and September 2001 taken by the Yohkoh Soft X-ray Telescope, showing variation in solar activity during a sunspot cycle. Image credit: Yohkoh/ISAS/Lockheed-Martin/NAOJ/U. Tokyo/NASA.
Montage of images of solar activity between August 1991 and September 2001 taken by the Yohkoh Soft X-ray Telescope, showing variation in solar activity during a sunspot cycle. Image credit: Yohkoh/ISAS/Lockheed-Martin/NAOJ/U. Tokyo/NASA.
Our Sun has an approximately 11-year activity cycle. During peak periods, it exhibits lots of solar flares and sunspots. Magnetic bubbles of charged particles (coronal mass ejections) may burst from the surface during this period, streaming material into space. These ejections can affect satellites and powerlines on Earth. During lull periods, such activity may almost stop altogether. But the 11-year cycle isn’t quite able to predict all of the Sun’s behaviour — which can seem erratic at times. Zharkova and her colleagues (Professor Simon Shepherd of Bradford University, Dr Helen Popova of Lomonosov Moscow State University, and Dr Sergei Zarkhov of Hull University) have found a way to account for the discrepancies: a ‘double dynamo’ system.

The Sun, like all stars, is a large nuclear fusion reactor that generates powerful magnetic fields, similar to a dynamo. The model developed by Zharkova’s team suggests there are two dynamos at work in the Sun; one close to the surface and one deep within the convection zone. They found this dual dynamo system could explain aspects of the solar cycle with much greater accuracy than before — possibly leading to enhanced predictions of future solar behaviour. “We found magnetic wave components appearing in pairs; originating in two different layers in the Sun’s interior. They both have a frequency of approximately 11 years, although this frequency is slightly different [for both] and they are offset in time,” says Zharkova. The two magnetic waves either reinforce one another to produce high activity or cancel out to create lull periods.

Comparison of three images over four years apart illustrates how the level of solar activity has risen from near minimum to near maximum in the Sun's 11-years solar cycle. Image credit: SOHO/ESA/NASA.
Comparison of three images over four years apart illustrates how the level of solar activity has risen from near minimum to near maximum in the Sun’s 11-years solar cycle. Image credit: SOHO/ESA/NASA.
She and her colleagues used magnetic field observations from the Wilcox Solar Observatory in California for three solar cycles, from the period of 1976 to 2008. In addition, they compared their predictions to average sunspot numbers — another strong marker of solar activity. All the predictions and observations matched closely. Their predictions using the model suggest an interesting longer-term trend beyond the 11-year cycle. It shows that solar activity will fall by 60 percent during the 2030s, to conditions last seen during the Maunder Minimum of 1645-1715. “Over the cycle, the waves fluctuate between the Sun’s northern and southern hemispheres. Combining both waves together and comparing to real data for the current solar cycle, we found that our predictions showed an accuracy of 97 percent,” says Zharkova.

The model predicts that the magnetic wave pairs will become increasingly offset during Cycle 25, which peaks in 2022. Then during Cycle 26, which covers the decade from 2030-2040, the two waves will become exactly out of synch, cancelling one another out. This will cause a significant reduction in solar activity. “In cycle 26, the two waves exactly mirror each other, peaking at the same time but in opposite hemispheres of the Sun. We predict that this will lead to the properties of a ‘Maunder minimum’,” says Zharkova.


A lookback at the NAM2015
The National Astronomy Meeting 2015, organised by the Royal Astronomical Society (RAS), is the second time the event has been held in Llandudno. Venue Cymru, where the conference was held, overlooks the Irish Sea and was a popular venue with attendees. This year saw a lively lecture on the Rosetta mission to Comet 67/P by Dr Matt Taylor of the European Space Agency. The public lecture this year by Lord Martin Rees, attended by well-over 500 people, pondered humanity’s future in space and the fate of the Universe.

Attendees at the National Astronomy Meeting 2015 at Venue Cymru, Llandudno, looking at posters. Image credit: Sian Prosser, RAS.
Attendees at the National Astronomy Meeting 2015 at Venue Cymru, Llandudno, looking at posters. Image credit: Sian Prosser, RAS.
Topics covered during this year’s conference ranged from exoplanetary science, a look forward to New Horizons’ flyby of Pluto (see this story), large-scale structure of the Universe and dark matter, and galaxy surveys. A lot of fun was had by attendees trying out an Oculus Rift virtual Reality headset running planetarium software. This demonstrated the StarsightVR Project (see former story). There was also a strong emphasis on solar science and associated space weather. Also evident at this year’s conference was a strong emphasis on outreach, with teachers invited to the event for the first time-ever, for a STEM (science, technology, engineering, mathematics) subjects workshop. The RAS Patrick Moore Medal for outstanding teaching was presented during this workshop. But there are two aspects to outreach:

One involves an emphasis on astronomy and science education in schools (the aforementioned STEM subjects). The Royal Astronomical Society’s Education and Outreach Officer, Dr Sheila Kanani, was involved in outreach activities with both primary and secondary school-aged pupils from the local area. “We had forty 13 to 18 year-olds at the conference to hear a 45-minute talk by Matt Taylor, with 15 minutes for questions. That went so well it became a 90-minute talk with 45 minutes of questions!” she says. Eight to ten year-olds from several local primary schools were treated to a bilingual demonstration of the Astrodome inflatable planetarium, by Techniquest Glyndwr. Kanani says, “The reason we do outreach work like this is to inspire future generations to take up STEM subjects, as we live in an increasingly technological era. Space is a great hook for that.”

Kanani mentions that another reason for outreach is to provide a link between scientists and members of the public. This formed the other aspect of outreach at NAM. Scientists are increasingly asking the public to ‘get their hands dirty’ and contribute to real science. This is increasingly important in an age of unprecedented quantities of data, which professional scientists could never hope to check themselves in its entirety. In a talk on Tuesday, postgraduate student at Oxford University Rebecca Smethurst, outlined an upcoming project called ‘Snapchat Supernovae’, which will feature as part of the enormously successful Galaxy Zoo public science initiative. In her talk Smethurst said, “Immediacy is important for supernovae as they need to be followed up spectroscopically before they fade.” The public’s input will be crucial in flagging such events.

TV Impressionist, RAS fellow and keen amateur astronomer Jon Culshaw entertains attendees at the NAM conference dinner and awards ceremony. Image credit: Sian Prosser, RAS.
TV Impressionist, RAS fellow and keen amateur astronomer Jon Culshaw entertains attendees at the NAM conference dinner and awards ceremony. Image credit: Sian Prosser, RAS.
Mandy Bailey, one of the main conference organisers, recalls her favourite moments from this year’s event. “When everything to do with organising NAM, setting up the website, etc. had been completed — and all the stress had gone, that was a good moment,” she says. She then added, “It was great to see the venue filling up with attendees and seeing the posters go up. The icing on the cake was Jon Culshaw at the conference dinner, which included the RAS awards’ ceremony. Every time someone went up to collect their award the band played space-themed music from Doctor Who, 2001, The Big Bang Theory, etc. It was wonderful.”