Exo-Moons and Goblins

The discovery of planets orbiting around other stars has been one of humankinds greatest achievements. The existance of these ‘exo-planets’ can challenge our perception of our place in the universe. Since the first confirmed detection of a planet around another normal star (51 Peg) in 1995, many thousands of planets have been discovered. Indeed, it is likely that most stars will have their own system of planets. It is important in answering the question – is there intelligent life out there?

Hydrogen-Deficient Stars 2018 – Armagh Observatory and Planetarium

September 2018 will see over 50 astronomers from around the world gather at the Armagh Observatory and Planetarium to discuss the latest news about hydrogen-deficient stars. These stars have lost nearly all the hydrogen from which they were made, to leave only nuclear ash. Astronomers want to learn how these rare and short-lived remnants formed, and what drives their spectacular changes in brightness. 

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.