Astronomical Society of Coonabarabran

OUT OF THIS WORLD DISCOVERY HAS ASTRONOMERS IN A SPIN

Classroom science contributes to space research

By Liz Cutts

The previous record for fast rotating natural objects has been smashed.

Revolving once every 42.7 seconds, newly-discovered asteroid 2008 HJ has been classified as a 'superfast rotator' which makes it the fastest rotating natural object known in our solar system

The exciting discovery was made by British amateur astronomer, Richard Miles using the Faulkes Telescope South located at the Siding Spring Observatory in Coonabarabran.

Confirmation of his discovery was formally announced by the International Astronomical Union on Thursday, 22nd May.

He made his observations by operating the Faulkes Telescope South remotely via the Internet from his home in Dorset.

Scientists say the discovery will boost our sparse knowledge of near Earth asteroids and is another successful find for the Faulkes Telescope near-Earth asteroid project.

The previous record holder was asteroid 2000 DO8, discovered eight years ago and found to rotate once every 78 seconds.

"A discovery like this demonstrates the capabilities of amateur astronomers and school students to produce exciting scientific results if given the right tools," stated Dr. Paul Roche, director of the Faulkes Telescope Project at Cardiff University.

"By providing Richard with access to a big telescope we have smashed the previous record, and opened up the search for even faster objects to UK amateur astronomers and school students. This helps to put all that classroom science, maths and IT to real use!"

This latest discovery is the most recent outcome of a new project to use the Faulkes Telescopes, situated in Hawaii and Australia, to survey the properties of small (150-metre) near-Earth asteroids.

UK schools and colleges have already participated in the project, which in April had an early success having found that asteroid 2008 GP3 rotates once every 11.8 minutes.

Asteroid 2008 HJ was only the second object observed as part of this study.

The observations suggest that 2008 HJ is a compact stony object measuring some 12m x 24m in size - smaller than a tennis court yet probably having a mass in excess of 5,000 tonnes.

It was moving at almost forty-five kilometres per second (more than 100,000 mph) when it hurtled past the Earth in late April.

Since the asteroid was travelling so fast the telescope had to be continually repositioned so as to keep it in view as it tracked across the sky. Short exposures of a few seconds yielded trailed images and a tell-tale sign of a super-fast rotator was the observed change in brightness along the trail caused by the oblong-shaped asteroid turning and reflecting sunlight differently.

However, despite it being classified as a "near-Earth asteroid" (NEA), it came no closer than 1 million km and never posed a threat to our planet.

It is believed that most asteroids are probably fragments ejected from collisions between larger bodies which took place some time in the distant past. However, other objects may have originated when the solar nebula was formed over 4.6 billion years ago.

Amateur contribution
Because our knowledge of the near-Earth population of small asteroids is very limited, any observations made by schools and other amateurs can contribute directly to furthering understanding of these nearest neighbours.

The Faulkes team says that the early success for the Faulkes Telescope NEA project bodes well for the future and should prove especially encouraging to schools, colleges and other amateur astronomers looking to participate.

It is findings like these that demonstrate providing the public and schools with professional grade telescopes can lead to record-breaking astronomical discoveries.

"The idea of an amateur discovering something like this using Faulkes Telescope South is quite nice," added Dr. Roche.

"In the future we're hoping schools will get more involved in the whole process and it would be great if we could get some Australian schools onboard."

The challenge now is to find objects spinning even faster than asteroid 2008 HJ!

Note; The Faulkes Telescope Project is an educational charity based at the School of Physics and Astronomy at Cardiff University. Faulkes Telescope South at Siding Spring Observatory has a mirror diameter of 2-metres, stands around 8m tall and weighs almost 25 tonnes. It is a research-grade instrument, but is used by UK schools for around 4 hours each (Australian) night (corresponding with UK day time). Students can control the telescope live using a website; www.faulkes-telescope.com.

speeding_asteroid

Figure 1: (Speeding asteroid) The cigar-shaped speeding asteroid, 2008 HJ, (centre) moves almost 1,500 kilometres through space and makes almost a complete revolution in the time it took to snap this picture!