Astronomers from the University of Strasbourg recently took a long look at the black hole P13 of the galaxy NGC7793 about 12 million light years from Earth. Because the object was 100 times brighter than our sun it was generally assumed that it was very large.

“It was generally believed the maximum speed at which a black hole could swallow gas and produce light was tightly determined by its size. So it made sense to assume that P13 was bigger than the ordinary, less bright black holes we see in our own galaxy, the Milky Way,” said Dr Roberto Soria of the International Centre for Radio Astronomy Research (ICRAR) in a statement.

The researchers discovered, however, that the rules governing how much a black hole can eat are not hard and fast. P13’s ‘donor’ star is 20 times heavier than our sun and the researchers noted that one side of the star was always brighter than the other. ”

This allowed us to measure the time it takes for the black hole and the donor star to rotate around each other, which is 64 days, and to model the velocity of the two objects and the shape of the orbit. From this, we worked out that the black hole must be less than 15 times the mass of our Sun,” said Dr Soria.

The researchers calculated that the black hole was swallowing gas from the donor star at a rate 10x larger than what was thought possible. According to the researchers P13 is “…ingesting a weight equivalent to 100 billion billion hot dogs every minute.”

Hot dogs are an unusual choice for the measurement of matter, in large part because their weight is not standardized. However, according to Self Nutrition Data, they weigh approximately one-tenth of one pound. Using that measurement we can assume that the black hole is consuming 5 quadrillion (5,000,000,000,000,000) tons of gas per minute.

The research from Soria and his colleagues can be found in the journal Nature.