Clouds, Large and Small, of the Southern Sky

Welcome to Sky & Telescope’s new Southern Hemisphere stargazing column, in which month by month I’ll introduce you to some of the wonders to be found south of the celestial equator. I’ll be focusing mostly on sights that can be seen just with the naked eye — stars, constellations and the brighter (and sometimes darker!) deep sky objects. If you haven’t yet experienced the southern skies but hope to one day, let this column be your inspiration and guide.

Deep in January’s sky, far south of the equator, are two of the most amazing celestial showpieces — the Large and Small Magellanic Clouds. Easily visible from dark locations as two foggy expanses, they’re a bit harder for light-polluted city dwellers to discern. Each is a small galaxy near our own Milky Way, with the Large Magellanic Cloud around 160,000 light-years away and the Small Magellanic Cloud about 200,000 light-years distant.

When you first spot them, you really would think that they are just two wispy clouds. That they don’t drift with the wind is a bit of a giveaway that they are celestial in nature, however.

Known to Southern Hemisphere indigenous peoples since antiquity, the Magellanic Clouds have collected many names through the years. For a long while they were referred to by Europeans simply as Nubecula Major and Nubecula Minor, but their present names recall Ferdinand Magellan, who was the initial leader of a Spanish expedition to circumnavigate the globe between 1519 and 1522. Although he came to grief in a battle in the Philippines in April 1521, his colleagues completed the voyage.

It has to be said that not everyone is happy having the galaxies named after Magellan, due to his treatment of indigenous peoples encountered on the voyage and the expedition’s role in the opening up of South America to Spanish colonialism. Some have suggested renaming them simply the “Milky Clouds.”

The Large Magellanic Cloud (LMC) is the fourth-largest galaxy in our Local Group (behind the Andromeda Galaxy, our own Milky Way and the Triangulum Galaxy). It’s so large in apparent size — about 20 times the Moon’s apparent diameter — that it spans the border of two constellations, Dorado and Mensa.

The LMC is a marvellous sight through any optic, from binoculars to large telescopes, and contains many fine objects. Especially noteworthy is the huge region of ionized gas, NGC 2070, also known as the Tarantula Nebula or 30 Doradus.

Famously, the first bright supernova in almost 400 years was spotted in Tarantula in February 1987, designated SN 1987A. I remember seeing it, after I received a phone call from a friend who told me, “There’s a supernova in the LMC — get outside and take a look!” I promptly did so and saw a star where there had been none the night before . . .  indeed, where none had been for all of observational history.

We weren’t the only ones paying attention — astronomers everywhere, professional and amateur alike, dropped what they were doing and focused on SN 1987A in the weeks and months afterward. After all, humankind had been waiting nearly 400 years for a supernova bright enough to see by the naked eye — maybe it would be another 400 until before it happened again. 1987A has long since faded, but the memories of it haven’t.

The Small Magellanic Cloud (SMC) is a splendid sight, too. As its name suggests, it’s smaller than the LMC in both actual size and in apparent size, but it, too, crosses the boundary of two constellations, Hydrus and Tucana. Whereas the LMC has its own unique classification type — a Magellanic barred spiral — the SMC is considered to be an irregular dwarf galaxy.

While in the vicinity of the SMC, make sure you take in the nearby naked-eye globular cluster NGC 104, or 47 Tucanae. Southern Hemisphere astronomers consider themselves very lucky to have such a splendid globular so easily visible — at magnitude 4.1 and declination — 72°, it’s easily visible all year long for most people.

After savoring these showpieces of the night, let’s take a look at just a few more highlights for mid-January evenings.

Spaced out across the sky are three bright stellar beacons: High in the south-southeast is Canopus; in the south-southwest is Achernar; and in the southwest, Fomalhaut. These three stars are the 2nd-, 9th- and 18th-brightest in the sky at magnitudes –0.74, 0.46, and 1.16, respectively. They are also single, double, and triple star systems, respectively.

Achernar marks the end of the long, winding constellation Eridanus, the River, while Fomalhaut is the brightest star in the constellation Piscis Austrinus, the Southern Fish. Oddly, the fish, is located quite far from the river.

Finally, Crux, the Southern Cross, is perhaps the one thing that everyone wants to see when they first go stargazing in the south. Well, this time of year — the southern summer — isn’t the best time to see it. At mid-evening it can be found very low on the south-southeastern horizon, tilted almost upside down, so you need to wait until later in the night for it to really show itself. First-timers often have a bit of trouble spotting it, expecting to see something huge and prominent, but it’s in fact the smallest of all the 88 official constellations. Still, I consider it to be lovely and compact, and quite eye-catching once you know what to expect.

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Jonathan Nally was the launch editor for the Australian edition of this magazine in 2004, and served again as editor from 2014 to 2023. Back in 1988 he founded Australia’s first-ever amateur astronomy publication, Southern Astronomy, which later underwent a name change to Sky & Space. In 2001 he was the inaugural recipient of the Astronomical Society of Australia’s prestigious David Allen Prize for excellence in communicating astronomy to the public.