A guide to what's up in the sky for Southern Australia

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Starwatch for April 2026 (31st Mar 2026)

As you venture out these crisp autumn evenings for a look at the night sky, bid a fond farewell to our starry companions over summer, and welcome the stars that will become our friends during the frosty winter evenings ahead. Stars with names like Arcturus, Antares, Spica, and Regulus.

Over to the north, the constellation of Leo, the lion is quite prominent. Many different cultures have seen a lion in this pattern of stars. But others have seen a sickle, which forms the lion's head and shoulders, and a small triangle, which forms its hindquarters.
The brightest star in the sickle is Regulus; the heart of the lion. The brightest star in the triangle is Denebola, also known as Beta Leonis because it's Leo's second-brightest star. It's about half as bright as Regulus.
It is in that apparently vacant part of sky between Leo and Virgo, that we find the Virgo Cluster of Galaxies. A telescope will reveal dozens of galaxies. Each one is home to anywhere from a few million to hundreds of billions of stars. Using data obtained with the Hubble Space Telescope, astronomers now estimate that the distance between Earth and the centre of the Virgo Cluster is some 48 million light years. That means that the light left the galaxies 48 million years ago, travelling at a speed of 300,000 kilometres per second!
Very low in the west, red Betelguese, at the shoulder of Orion the Hunter bids us farewell, having been our companion during the warm summer months. Meanwhile, across the other side of the sky in the constellation of Scorpius, the Scorpion, Antares, another red star, rising in the east announces the coming of winter. For me, I don't think there are any other constellations in the sky that herald the coming of the seasons so well as these two do. Orion in the east, signals summer is around the corner, whilst Scorpius in the east, brings the chill winds of winter with it.
Antares, is a star of gargantuan proportions. If we replaced our Sun with it, then all the planets from Mercury through to Jupiter would all find themselves engulfed within it! Just below the tail of Scorpius, you can find the star clusters designated M6 and M7. Take the trouble to observe these with binoculars. They make a beautiful sight, with many bright stars sparkling like diamonds against a background of gold dust.
Further to the northeast, we find the constellation of Virgo. One of the most famous objects in the sky; a quasar known as 3C273, is located in this constellation. In the early 1960’s, 3C273 was known as a "radio star." Though astronomers could detect it with radio telescopes, they couldn't pinpoint its location well enough to see it with optical telescopes.

But that changed the day the Moon passed between the radio star and Earth, blocking its radio signals and allowing astronomers to pinpoint its location. With this information, they could find the object with optical telescopes for the first time.
Even then, they couldn't quite fathom what they saw. Photographic plates showed only an inconspicuous blue star. But when astronomers split the star's light into its individual wavelengths, they found that it was unlike any known star, galaxy, or nebula. Further study eventually revealed that it's over 3.5 billion light-years away, which means it must be incredibly bright. It's also small, which means its energy source must be incredibly powerful.

Today, astronomers believe that 3C 273 and the thousands of other known quasars are monstrous black holes encircled by disks of gas. As gas spirals into the black hole, it's heated, so it glows brightly; bright enough to be seen across the vast abyss of space and time.

High in the southern sky, we find Crux, the Southern Cross. It’s the smallest of the 88 constellations, but one of the most distinctive. This part of the sky is rich in stars, and I would encourage you to grab a pair of binoculars and scan along the Milky Way. Locate the object labelled 5139 on the star chart. Its proper name is Omega Centauri. In binoculars it resembles an out-of-focus star. You can just make it out with the naked eye from the city. It is actually a vast aggregation of some 10 million stars, all arranged in a spherical ball, about 16,000 light years away. The average distance between stars in this cluster, known as a globular cluster because of its shape, is 1 light year. This is about 4 times greater than the star density we are used to in our neighborhood. Imagine a sky filled with thousands of stars all shining brighter than Sirius. What a sight that would be!
More a telescopic object, than for binoculars, the Jewel Box star cluster (also known as NGC4755) not far from the Southern Cross, cannot be beat for pure splendour. It earned its name because it reminds observers of spying at a lady's collection of precious stones against black velvet. The many coloured stars make this object a definite tourist destination.






Whilst the Southern Cross is the smallest, Hydra, the water snake, is the longest of the 88 modern-day constellations. It’s so long that it takes many hours for the entire constellation to climb above the horizon. Yet Hydra is also one of the fainter constellations. In fact, from most cities, only one of its stars is easy to spot.
Alphard is about a third of the way up the southeastern sky as night falls. There are no other bright stars anywhere near it, so you shouldn’t have much trouble picking it out.
The traditional name Alphard is from the Arabic al-fard, "the individual", there being no other bright stars near it. Alphard is about 175 light-years away. At that great distance, the fact that we can see it so clearly tells us that the star is pretty remarkable. In fact, it’s a giant, puffed up to about 40 or 50 times the diameter of the Sun. The star is about 400 million years old, roughly one-tenth the age of the Sun. Yet it’s also about three times as massive as the Sun. Heavier stars “burn” through their nuclear fuel more quickly than less-massive stars, so they age more quickly.
Alphard is already entering the final stages of life. As it uses up the fuel in its core, its outer layers puff outward. They get cooler as they do so, which gives Alphard a reddish-orange color. In a fairly short time, astronomically speaking, those outer layers will stream away into space. That will leave only the star’s hot but dead core, a tiny remnant known as a white dwarf. It’ll be far too faint to see with the eye alone, depriving the water snake of its one bright light.
One major planet holds centre stage during these April nights. But that won’t be for much longer. Look for Jupiter low in the north-west at nightfall. Jupiter is like a mini solar system. The Sun’s largest planet has a family of almost a hundred known moons. Most of them are little more than chips of rock and ice no more than a few kilometres wide. But a few rank among the most interesting worlds in the solar system.

The four largest moons are Io, Europa, Ganymede, and Callisto. They account for more than 99.9 percent of the combined mass of all of Jupiter’s moons. They probably formed along with Jupiter itself, from dust and gas that encircled the new-born planet.

Io is the most volcanically active body in the solar system. It’s covered by hundreds of volcanoes, lakes of molten lava, and other features. The other three big moons appear to have oceans of liquid water buried below their icy crusts. And Europa’s ocean is considered one of the most likely homes for life in the solar system.

Some of Jupiter’s little moons could have formed at the same time as the big guys, then perhaps moved into different orbits. But most of them appear to be the remains of asteroids that Jupiter captured when they wandered close. The asteroids were blasted apart in big collisions, leaving small chunks of ice and rock in orbit around the planet.

Jupiter is best observed through a telescope, though even binoculars will show the four big moons like tiny stars lined up near the planet.

As mentioned last month, we have a visitor to our inner solar system. A new comet was discovered in mid-January that “could” put on quite a show for us in early April. Known as comet C/2026 A1 MAPS, it is a sungrazer comet, and believed to be a fragment of a huge comet which appeared in 371BCE, aka Aristotle’s Comet. Comets are very unpredictable. We won't really know how bright it will be or if it will survive its close encounter with the Sun. It will swing 160,000 km above the Sun's farside surface on April 4th.

Passing so close to the Sun could generate geyser-like streams of gas and dust erupting from its nucleus due to the high level of outgassing from solar heating, causing it to break to pieces. We just don’t know what will happen. If it does survive, keeps your eyes on the western sky, very close to the horizon, soon after sunset and say gidday to a visitor from far, far, away.

The Moon is Full on April 2, at Last Quarter on the 10th, New on the 17th and at First Quarter on April 24.

Below: The time is 5:44am ACST on the morning of April 16, 2026. The thin crescent Moon and three of the naked eye planets (Mercury, Mars and Saturn) make a very pretty sight low on the eastern horizon. All 4 objects just miss fitting in the field of view of 7x50 binoculars. (Created with Stellarium software).