Astronomers keeping an eye on a space visitor

Stargazers at Auckland’s Stardome Observatory are watching out for the close approach of a new comet in the skies above NZ this month.

Comet Lulin will pass closest to the Earth – coming within 61.3 million kilometres – on 24th February, when it is expected to brighten to become visible to the naked eye or at least easily seen through binoculars.

At present, the comet is at magnitude 7, which means that a reasonable sized telescope is required to spot it in any detail. Through the ­Edith Winstone Blackwell Zeiss Telescope at Stardome Observatory, the comet is currently revealed as a small, fuzzy oval.

Some astronomers are predicting that the comet may reach magnitude 4, which would make it possible to spot with the naked eye, but better seen with binoculars from within the moderate light pollution of inner Auckland City.

The exact brightness of Comet Lulin, however, cannot be confidently predicted because of the many variable factors that influence how it will appear from Earth.

In early 2007, Comet McNaught outperformed even the most optimistic predictions by lighting up the skies above Auckland, while the approach of Halley’s Comet in 1986 was not as bright as most astronomers had expected.

“There is just no knowing for sure exactly how bright Comet Lulin will get – comets are notoriously unpredictable,” said Dr Grant Christie, research astronomer at Stardome Observatory.

“But we are keeping an eye out each clear night and will be documenting its path in case it does flare up and become a spectacle.

“We will also make accurate positional measurements that are used to refine the comet’s orbit.”

Dr Christie says that if the comet does brighten significantly, NZers will have a good opportunity to see a relatively unusual astronomical event.

Comet Lulin (C/2007 N3) was discovered by Taiwanese and Chinese astronomers in 2007 using images taken at Lulin Observatory in Taiwan. This is thought to be the comet’s first ever approach into the inner solar system.

If Comet Lulin does brighten to a reasonable magnitude, Stardome Observatory will open for special comet viewing sessions in February.

To view Comet Lulin:

Now: Comet Lulin is currently located in the constellation of Libra, visible to the north east from 1.00 a.m.

Later in the month: From 20th February, Comet Lulin will be in the constellation Leo, visible to the north east from 11.00 p.m. The comet will pass very close to the planet Saturn in the north at its closest approach on 24th February.