47 Tucanae – Astronomy Now

Star discovered in closest known orbit around likely black hole

14 March 2017 Stephen Clark

Astronomers have found evidence for a star that whips around a black hole about twice an hour. This may be the tightest orbital dance ever witnessed for a likely black hole and a companion star.

A middleweight black hole hides at center of giant star cluster

11 February 2017 Stephen Clark

All known black holes fall into two categories: small, stellar-mass black holes weighing a few Suns, and supermassive black holes weighing millions or billions of Suns. Astronomers expect that intermediate-mass black holes weighing 100 – 10,000 Suns also exist, but so far no conclusive proof of such middleweights has been found. Astronomers have announced new evidence that an intermediate-mass black hole (IMBH) weighing 2,200 Suns is hiding at the center of the globular star cluster 47 Tucanae.

Hubble reveals NGC 299 within the Small Magellanic Cloud

17 October 2016 Astronomy Now

It may be famous for hosting the Small Magellanic Cloud (SMC) and 47 Tucanae, the second brightest globular cluster in the night sky, but the southern constellation of Tucana (The Toucan) also possesses a variety of unsung cosmic beauties. One such beauty is NGC 299, an open star cluster located within the SMC just under 200,000 light-years away.

Millisecond pulsars in globular cluster 47 Tucanae

3 October 2016 Astronomy Now

Pulsars are rapidly spinning neutron stars that emit electromagnetic radiation in a sweeping, lighthouse-like beam. They are dramatic, powerful probes of supernovae, their progenitor stars. Astronomers have measured the orbital parameters of four millisecond pulsars in the globular cluster 47 Tucanae and modelled their possible formation and evolution paths.

South by Phil Hart

13 September 2016 Astronomy Now

The Southern Cross constellation of the Milky Way, visible in the southern sky creates a guiding light along Bucklands Lane in Central Goldfields Shire, Victoria, Australia.

Strange globular cluster recalls Milky Way’s infancy

14 December 2015 Astronomy Now

When our galaxy was born, around 13,000 million years ago, a plethora of clusters containing millions of stars emerged. But over time, they have been disappearing. However, hidden behind younger stars that formed later, some old and dying star clusters remain, such as the so-called E 3. European astronomers have now studied this testimony to the beginnings of our galaxy.

Discovery of white dwarf companions of millisecond pulsars

4 October 2015 Astronomy Now

When a massive star ends its life in a spectacular supernova explosion, it can leave behind a rapidly spinning neutron star with a period of 1-10 milliseconds. Such objects that emit electromagnetic radiation in a lighthouse-like beam sweeping past the Earth are known as millisecond pulsars. CfA astronomers have identified white dwarf companions of two more millisecond pulsars in the spectacular globular cluster 47 Tucanae.

Hubble catches a stellar exodus in action

17 May 2015 Astronomy Now

Using NASA’s Hubble Space Telescope, astronomers have captured for the first time snapshots of fledgling white dwarf stars beginning their slow-paced, 40-million-year migration from the crowded centre of giant globular cluster 47 Tucanae to the less populated suburbs.