Despite physicists ' insistency and ease of deliberation , ethereal body are not perfect spheres ( or point masses ) . Their surfaces could be rugged or their boundaries indecipherable . When it comes to star , the one we know best is the Sun and it seems like we do not know it quite as well as we thought – unlike ways to quantify its sizing do not exactly fit in on a single number .

The officially accepted wheel spoke of the Sun is estimated to be 695,700 kilometers ( 432,288 miles ) . This was launch in 2015 by theInternational Astronomical Unionand it is estimated by observing the photosphere , the deepest level of the atmosphere of the Sun . That is what we unremarkably view the surface of the Sun and what is used in models .

But this is not the only fashion to measure the size of the Sun . Researchers have used all different method to estimate the size of our lead . In new work , there is a small difference ; the generator believe that the radius of the Sun is a few hundredths percent big than the official photospheric radius .

Researchers Takata and Gough , from the University of Tokyo and the Institute of Astronomy severally , have appliedasteroseismologyto the Sun . They tracked the motion of waves within our star topology , literal solar oscillations . These oscillations are fuck so incisively that they can be used to make estimation of the general properties of the Sun , including its sizing .

Sound wafture name f - waves have been used in the yesteryear to estimate the radius . These waves are quite close to the surface and using them , researchers found a value that was different from the photospheric estimate . In the Modern study , Takata and Gough look at phosphorus - waves . These are waves that pass through the entireness of the Sun , including its core .

“ It ’s a different method . I would n’t say it ’s better . It has some advantages and disadvantages . P - modes are sound wave , and they circularise right through the Sun . So they are in reality giving a measure of the entire Sun . Whereas the f - modal value is a surface undulation and it ’s assess the surface layers,”Professor Douglas Goughsaid to IFLScience when asked about take this method acting to estimate the size of the Sun .

The newspaper found the radius of the Sun to be 695,780 kilometers ( 432,340 nautical mile ) , about 80 kilometers larger than the prescribed record . The difference is small but it matters with the high - precision analysis man acquit on the Sun and beyond . And it might entail that the current model of the Sun is not exactly correct .

“ The acoustic wafture are measuring things deeper down . They are give you a measure of the radius of the Sun as seen from the interior of the Sun , rather than , if you care , from the exterior . And so that ’s the difference . And so there are two dissimilar measures , ” Professor Gough explained to IFLScience .

Why are undulation methods and ocular methods giving different results ? It is presently ill-defined . One possibility Tanaka and Gough are keen to look into has to do with thesolar Hz , the magnetic declination in activity that our star topology experiences every 11 years .

It is potential that the round might affect more so the surface and brightness of the Sun , so altering the measurements in the f - mode and photosphere . But it is equally potential that it ’s a deeper phenomenon , and that p - wave will be affect too , and the differences might have to be found elsewhere .

There is a batch going on in the Sun and we do not fully understand our maven . This subject field confirms that more research is necessary to figure out the many mysteries environ the Sun , but low magnetic declination in radius may affect other bailiwick beyond uranology . Solar neutrinos , for object lesson , come from the core of the Sun and they are analyze here on Earth , bring home the bacon brainwave into nuclear physics . Their numbers , however , are very sensitive to the sizing of the Sun . If the Sun is slightly bigger or smaller , the flux will be much bigger or smaller – something very important in many possibility .

The study is publish inMonthly Notices of the Royal Astronomical Society .