What is Radio Astronomy?

Our view of the cosmos is biased by the vista that is apparent to our eyes.  This is what the view in what we call the optically visible portion of the spectrum. To the unaided eye it is a view of a universe full of stars, together with five planets, one Moon and of course the Sun. When augmented with a telescope, our eyes can then see a universe full of galaxies – giant cities of stars.

Measuring the Universe – 150th birthday of Henrietta Swan Leavitt

July 4, 2018 saw the 150th birthday of Henrietta Swan Leavitt (1868 – 1921), one of the most important astronomers of the 20th century. Born in Lancaster, Massachusetts, Leavitt graduated from Radfcliffe College, Harvard, in 1892. She then stayed on at the Harvard College Observatory as a volunteer research assistant. Whilst attempting a graduate degree in astronomy and travelling in Europe, she became ill with grave consequences for her hearing. In 1902, then director, Edward Pickering, invited Henrietta to join the permanent staff at Harvard, where she was assigned to study “variable” stars.

A new ultra-compact binary star

Approximately every other star in the Milky Way galaxy is in a ‘binary’ system. These binaries are made up of two stars orbiting around a common centre of gravity. The time taken for the stars in the binary to make one revolution is called the ‘orbital period’. Binaries have a wide range of orbital period. The closest stellar system to the Sun is alpha Centauri which has two stars not unlike our Sun orbiting around one another every 80 years. A third member of the system, Proxima Centauri, which is much smaller red dwarf star, orbits around these two stars once every 10,000 years.