On the night of May 20th, 1863, Mr N R Pogson, the government astronomer at Madras, observed a star of the ninth magnitude on a spot in the constellation Scorpio, where no star had been seen in the months of April and May during the last nine years.
At first it was supposed to be one of the minor planets, but
a series of micrometrical measures of its position with respect to other stars
near it, made the same night, established its fixity, and revealed its true
character.
On the following night it was decidedly less bright, and by
the 28th May it had diminished to less than the twelfth magnitude.
Strong moonlight then interfered with observations, but on the night of June 1st,
during the darkness caused by the total eclipse of the Moon, it was again
looked for but was no longer visible.
Only three other stars are known, discovered respectively by
Mr Hind, Mr Baxendell and Herr Auwers, whose appearances and disappearances
take placed so suddenly; and every addition to the list of objects so
remarkable is regarded with considerable interest by astronomers.
Mr Pogson called his new variable star U Scorpio.
Today we know that U Scorpio is a recurrent nova system that
has been seen to brighten up not only in 1863, but also 1906, 1936, 1979, 1987,
1999, 2010, and 2022. Pogson’s observations from 1863 are the only ones known regarding that outburst.
None of the outbursts were bright enough to be seen by the
naked eye, all needing either binoculars or a small telescope.
www.theramblingastronomer.co.uk
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