Sir Frank Watson Dyson (January 8 1868 – May 25 1939) was an English astronomer.

He was Astronomer Royal for Scotland from 1905 to 1910, and Astronomer Royal (and director of the Royal Greenwich Observatory) from 1910 to 1933. In 1928, he introduced a new free-pendulum clock in the Observatory. This wireless transmission meant that Greenwich Mean Time was more accurate. He also invented the "six pips" in 1924.

Dyson was born in Measham, near Ashby-de-la-Zouch in England. He was knighted in 1915. He died while traveling from Australia to England in 1939.

Between 1894–1906, Dyson lived at 6 Vanbrugh Hill, Blackheath, London SE3. The house is now marked by a blue plaque.

Despite their similarity in name, Freeman Dyson is not related. However, the younger Dyson does credit Sir Frank with sparking his interest in astronomy; because they shared the same last name, Sir Frank's achievements were discussed by Freeman Dyson's family when he was a young boy. Inspired, Dyson's first attempt at writing was a 1931 piece of juvenalia entitled "Sir Phillip Robert's Erolunar Collision" — Sir Philip being a thinly disguised version of Sir Frank.

A crater on the Moon is named after him, as is the asteroid 1241 Dysona .

He won the Bruce Medal in 1922 and the Gold Medal of the Royal Astronomical Society in 1925.

External links

• Bruce Medal page
• Awarding of Bruce Medal: PASP 34 (1922) 2
• Awarding of RAS gold medal: MNRAS 85 (1925) 672

Obituaries

• Astronomische Nachrichten 268 (1939) 395/396 (one line)
• Monthly Notices of the Royal Astronomical Society 100 (1940) 238
• The Observatory 62 (1939) 179
• Publications of the Astronomical Society of the Pacific 51 (1939) 336