StarDate

There just aren’t enough superlatives to describe the galaxy OJ 287. It’s a quasar – an especially bright object powered by two supermassive black holes.

One of them is about 150 million times as massive as the Sun. The other is 18 billion times the Sun’s mass – one of the heaviest black holes yet seen. They team up to produce outbursts that are a trillion times brighter than the Sun – brighter than all the stars in the Milky Way Galaxy combined.

OJ 287 is always bright. But every few years, it flares up – the result of interactions between the black holes.

Each of them is encircled by a giant disk of gas. As the gas spirals in, it gets extremely hot. That makes the disks extremely bright.

The smaller black hole orbits the larger one every 12 years. The orbit is tilted. So every six years, the black hole plunges through the disk around the larger black hole. That can heat some regions to trillions of degrees, producing the flare-ups.

Astronomers recently used radio telescopes to take a picture of the system. They saw a long “jet” of particles from the smaller black hole. The jet is twisted by the interactions between the black holes – confirming the profile of this amazing system.

OJ 287 is in Cancer, which is low in the east at nightfall. Even though it’s billions of light-years away, OJ 287 is bright enough to see through most amateur telescopes.

Script by Damond Benningfield

Saturn’s rings are among the most beautiful features in the solar system – and the most mysterious. Scientists continue to debate how and when the rings formed, and how much longer they might hang around.

But the rings aren’t Saturn’s only beautiful and mysterious feature. An almost perfect hexagon of clouds wraps around the planet’s north pole. And scientists continue to debate how it formed and what keeps it going.

Saturn is the second-largest planet in the solar system – nine-and-a-half times the diameter of Earth. So the hexagon is giant as well – more than twice as wide as Earth. And it’s long-lasting – it was first observed in 1981.

There are several ideas about what shapes the hexagon. Perhaps the leading idea says that winds deep in the atmosphere blow at different speeds at different latitudes. As these jet streams rub against other, they create waves that ripple to the top of the clouds. Those clouds form regular patterns – the sides of the hexagon.

There’s one other mystery about the hexagon: It appears only at the north pole, not the south. So scientists are still working to explain this beautiful feature at the top of a beautiful planet.

Saturn poses near the Moon the next couple of evenings. It looks like a bright golden star. It’s to the upper left of the Moon tonight, and a bit farther below the Moon tomorrow night.

Tomorrow: a system that defies description.

Script by Damond Benningfield

Orion climbs high across the sky on winter nights. It’s in the east-southeast at nightfall, and it’s easy to pick out. Look for the constellation’s “belt” – a short line of three stars that points straight up.

In ancient Greece and Rome, Orion was known as a mighty hunter. But in ancient Egypt, the figure was even mightier. It represented Osiris, the god of the underworld. In fact, he was thought to reside in the stars of the belt.

The story of Osiris dates to Egypt’s Old Kingdom, at least 4500 years ago. It says that Osiris was a great king. But he was murdered and chopped apart by his brother, Set. Isis, Osiris’s wife and sister, recovered the pieces, wrapped him in bandages, and used a magic spell to resurrect him. She then gave birth to Horus, who avenged his father by killing Set.

As a god, Osiris reigned over the underworld. When the Sun passed through the underworld at night, Osiris gave new life to the Sun god, Re. So he became known as the god of rebirth and resurrection. He was associated with the start of a new year, when the Nile brought lifegiving floods to the fields.

When a king died, he joined Osiris in the stars. Some researchers have suggested that a shaft in the Great Pyramid of Giza aimed toward Orion’s Belt at the time it was built. Others say there’s no astronomical significance to the shaft. But just about everyone agrees that Orion’s Belt was considered the resting place of Osiris.

Script by Damond Benningfield

Orion is a land of monsters. It’s packed with stars that are among the most impressive in the galaxy – they’re big, heavy, and bright. Even among all those superstars, though, Lambda Orionis stands out. It consists of two monster stars. The largest is about 35 times the mass of the Sun, and perhaps 200 thousand times brighter.

Orion is home to so many major stars because it’s on the leading edge of a spiral arm – a zone where many new stars are being born. Lambda belongs to a cluster that’s one hotbed of starbirth. It contains many stars of all sizes and masses. Lambda’s main star is the brightest and heaviest in the cluster.

The cluster is encircled by a ring of gas and dust – probably outlining the shockwave of a massive star that exploded as a supernova. Lambda’s radiation zaps the material in the ring, making it glow.

Lambda is only a few million years old, yet its time is almost up. Because it’s so massive, it will live a very short life. Soon, it may explode as a supernova, with its core collapsing to form a black hole.

On the other hand, it might be massive enough for the entire star to become a black hole, with no explosion at all – a monstrous ending for a monster star.

Orion is in the east and southeast at nightfall. Bright orange Betelgeuse marks its left shoulder. Lambda is to the upper right. Despite its true brilliance, it looks fainter than many of the hunter’s other impressive stars.

Script by Damond Benningfield

For a while now, astronomers have suspected that Betelgeuse has a companion. And they might have found it. If it really exists, though, it won’t be around for long.

Betelgeuse is a supergiant. It’s about 15 times as massive as the Sun, hundreds of times wider than the Sun, and tens of thousands of times brighter.

There’s a wobble in the star’s light that lasts about six years – possibly caused by the gravity of a smaller companion star. A team looked for the companion in 2020 and 2024. The team stacked thousands of short-exposure images together, producing a sharp view of the system.

The researchers didn’t see anything in 2020 – but they hadn’t expected to. The two stars were predicted to be too close together to tell them apart. But the team did see the companion in 2024, when the stars were farther apart.

If the star really exists, it would be a little bigger and heavier than the Sun. But it’s so close to Betelgeuse that it’s enveloped in the supergiant’s outer atmosphere. That’s pulling the star closer in. Eventually, it should get so close that the gravity of Betelgeuse will rip it apart. And even if that doesn’t happen, before long Betelgeuse will explode as a supernova – bad news for both stars.

Betelgeuse is the bright orange shoulder of Orion the hunter. It’s a third of the way up in the east-southeast at nightfall, to the left of Orion’s Belt.

More about Orion tomorrow.

Script by Damond Benningfield