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Star dates Van Gogh canvas

The White House at Night, which hangs in St Petersburg's Hermitage Museum, shows a house at twilight with a prominent star with a yellow halo in the sky.

Astronomers at Southwest Texas State University in San Marcos calculated that the star is Venus, which was bright in the evening sky in June 1890 when Van Gogh is believed to have painted the picture.

They then organised a field trip to the small town of Auvers-sur-Oise, north-west of Paris, and located the white house itself.

This enabled them to work out the position from where Van Gogh made the painting.

The researchers, Donald Olson and Russell Doescher, say that the canvas was painted from the bottom up during the course of an afternoon and early evening.

"You can see it is about seven o'clock from the sunlight on the house, but as the sun sets, Venus becomes bright and obvious," said Mr Doescher, who added that he was astonished by the accuracy of the star's position in the picture.

Turbulent history

Using computer programmes, the astronomers calculated that Venus was in the position shown in the painting at around eight o'clock on 16 June 1890 - just six weeks before the artist killed himself.

The White House at Night has a history almost as turbulent as Van Gogh's.

It was hidden from Nazi looters and only re-emerged in Russia in 1995, after the fall of the Soviet Union.