Henry Crozier Keating Plummer facts for kids

Henry Crozier Keating Plummer was an English astronomer. He was born on October 24, 1875, and passed away on September 30, 1946. He was known for his important work studying stars and galaxies.

His Early Life and Learning

Henry Plummer was born in Oxford, England. His father, William Edward Plummer, was also involved in astronomy. Henry went to St. Edward's School and later Oxford University. He studied physics and then taught mathematics at Owen's College in Manchester.

Working as an Astronomer

In 1900, Henry Plummer started working as an assistant at the Radcliffe Observatory in Oxford. His father had also worked there before him. Henry stayed at this observatory for about twelve years. During this time, he also spent a year as a special researcher at Lick Observatory in the United States.

In 1912, Henry Plummer became the Andrews Professor of Astronomy at Trinity College, Dublin. This important job also gave him the title of Royal Astronomer of Ireland. He was the last person to hold both of these positions. He was also in charge of the Dunsink Observatory from 1912 to 1920.

In 1921, he joined the Military College of Science at Woolwich as a professor of mathematics. He worked there until he retired in 1940. He also served as the President of the Royal Astronomical Society from 1939 to 1941.

His Contributions to Astronomy

During his career, Henry Plummer helped create the Astrographic Catalogue, which is a huge map of stars. He also wrote many scientific papers. He studied how the brightness of certain stars changed over time. He also looked at how cepheid variable stars pulsate, or expand and shrink.

In 1911, he created a special mathematical formula. This formula helps scientists understand how gravity works in groups of stars called globular clusters. It also helps with large groups of stars called galaxies that are shaped like a ball. This formula is now known as the Plummer potential. In 1918, he published a book called An Introductory Treatise on Dynamical Astronomy. You can find it online here: An Introductory Treatise on Dynamical Astronomy.

He also studied the history of science. He was part of a special committee from the Royal Society. This group worked to publish the important papers of Sir Isaac Newton.

Awards and Recognition

Henry Plummer received several honors for his work:

• He became a Fellow of the Royal Society in 1920.
• He became a Fellow of the Royal Astronomical Society in 1899.
• A crater on the Moon is named after him. It is called Plummer.