No, it's not a burgeoning population of beard-growing, cold drip coffee-sipping hipsters.

It's their grid street layouts, and a spectacular celestial event they make possible.

In New York, the biannual event is called "Manhattanhenge". In Melbourne, it's dubbed "Melbhenge".

And it happens when the sun sets precisely in line with the city's streets, between the city's skyscrapers.

These events take their names from the similar phenomenon at Stonehenge, when the setting sun appears directly between the mysterious monoliths at certain times of the year.

On Tuesday night, astronomers in Melbourne had their gaze firmly fixed west in a bid to catch a glimpse of the unique sunset.

The prime viewing time was at exactly 8.27pm.

"We don't know why the ancient druids of Britain created Stonehenge where sunlight streamed between gaps in thousands of tons of rock at key times of the year," astrophysicist Dr Alan Duffy said.

"We do know that Melbhenge has more to do with efficient city planning by Robert Hoddle in 1837, but the effect is the same.

"Melbhenge occurs at sunset a couple of times a year when the sun sets directly between the skyscrapers going along the Hoddle grid; that is Collins, Bourke, Lonsdale streets.

"You get this beautiful alignment of the setting sun ... framed in a mile-long corridor."

Locations closer to Spring Street make for the best viewing, Dr Duffy said.

Melbourne Henge from Bourke Street Mall on Tuesday night. Photo: Peter Choong

"You may find, depending on exactly how far down the grid you are, how close to the west side of city [you are], you will definitely be able to frame the sun," he said.

He was appealing to other Melbhenge enthusiasts to help plot the best points in the city to view the evening light show.

"We'll try to build up a map, so over these next couple of years we find the perfect viewing location," Dr Duffy said.

The next opportunity to catch the unique sunset will be on November 3 this year.

 

#sunset #melbhenge #melbournehenge #melbourne #melbournecity

A photo posted by reynaldi darma (@me_rayman) on Feb 7, 2017 at 2:00am PST