What is Betelgeuse B?

Betelgeuse B is a companion star to the red supergiant Betelgeuse, with a mass of approximately 2–3 solar masses, recently imaged directly by ESO's VLT/SPHERE instrument.

How far away is the wandering black hole discovered by Swift?

The wandering black hole is located approximately 30,000 light-years from its galaxy's core, in a galaxy roughly 750 million light-years away from Earth.

When will the Nancy Grace Roman Space Telescope launch?

The Nancy Grace Roman Space Telescope is scheduled to launch on 30 August 2026.

What problem is affecting the LINK servicing spacecraft?

LINK began spinning over the weekend with two of three reaction wheels non-operable and some cold-gas thruster degradation; the team is using electric xenon thrusters to arrest the spin.

When do the Perseids peak in 2026?

The Perseids peak on the moonless night of 12–13 August 2026, coinciding with a total solar eclipse.

Betelgeuse Is Not Alone!

Avery: One of the most famous stars in the whole

night sky has been keeping a secret for about

100 years.

Anna: And this week, a telescope in the Chilean

desert finally caught it red handed.

Betelgeuse, it turns out, is not alone.

Avery: Also ahead, a black hole caught wandering the

lonely outskirts of a galaxy dreading a

star tens of thousands of light years from

where any black hole has a right to be.

Anna: NASA's next great observatory gets its tank

filled and a date on the calendar.

Avery: And the little spacecraft sent to rescue an

aging telescope suddenly needs rescuing

itself. G', day, and welcome to Astronomy

Daily, your daily dose of space and astronomy

news. I'm Avery.

Anna: And I'm, um, anna. It's Wednesday, the 29th

of July, four stories and a look at the sky

from both hemispheres. Let's get into it.

If you've ever looked up at Orion, and from

Sydney or Seattle, just about everyone has,

you've seen tonight's star Betelgeuse,

that deep orange point marking the hunter's

shoulder. It's a red supergiant, roughly

650 light years away, and it is

enormous. Drop it where our sun sits and it

would swallow the orbit of Jupiter.

Avery: And it's famous for misbehaving. It

flickers.

Anna: It does. Betelgeuse brightens and dims on

a whole set of overlapping cycles. And people

have been writing that down for more than a

thousand years. But there's one rhythm, um,

in particular, a slow beat about six years

long that astronomers have never been able to

fully explain. And for almost a century,

one idea kept coming back. What if

Betelgeuse has a companion, a second star,

orbiting close, tugging on it?

Avery: The famous Betel Buddy.

Anna: That's the affectionate nickname, yes. The

trouble is nobody had ever seen it. And you

can see why. Imagine trying to spot a

candle sitting right next to a lighthouse.

Betelgeuse is so blindingly bright and so

physically huge that any little companion

tucked in beside it just drowns in the glare.

For a hundred years, it stayed a hypothesis.

Avery: So what changed?

Anna: A team led by Miguel Montargis at the Paris

Observatory in Chile, the vlt,

and an instrument called Sphere that's built

for exactly this job. Blocking out a bright

star to hunt for faint things right beside

it. And crucially, they picked their moment.

They observed in December 2024, at the

point in the orbit when the companion was

predicted to swing out as far from Betelgeuse

as it ever gets from seen from Earth. Best

possible chance to split the two apart. And

there it was. A faint little source right

Where a companion should be. Their paper

landed yesterday, 28th July in the journal

Astronomy and Astrophysics. And Montargis

called it the end of a century long quest.

After a hundred years of arguing about it, we

have a direct image of what is very likely

Betelgeuse B.

Avery: That gives me chills, honestly. A star that

people have watched since antiquity and we're

still learning brand new things about it.

Anna: And here's the lovely twist. The reason they

could see it at all is that it surprised

them. The companion was predicted to be

roughly the mass of our Sun. But the data

say it's bigger than that, something like two

to three times the Sun's mass. Montargis put

it beautifully, because it's more massive

than we expected, it's brighter than we

expected, and that's the only reason it

peeked out of the glare. If it had been as

small as the textbook said, they might have

missed it entirely.

Avery: So the companion did us a favor by being

chunkier than advertised. What is it though?

Another supergiant?

Anna: No, nothing like Betelgeuse. Think of it as

a young, hot, fairly ordinary star,

but locked in a very awkward orbit.

It appears to circle so close that it's

essentially skimming through the outer puffed

up layers of the supergiant. And that has

consequences. That orbit is almost

certainly what paces that mysterious M6

year brightness cycle. But it's also most

likely a death sentence for the companion.

Avery: Ooh, M. Go on.

Anna: Plowing through a supergiant's outer

atmosphere means constant drag. Every

orbit, the little star loses a bit of energy.

And models suggest it's slowly spiraling

inward on astronomical timescales.

Betelgeuse is very likely to swallow its

own companion. Not tomorrow. We're talking

thousands of years. But the relationship is,

let's say, not built to last.

Avery: The lighthouse eats the candle.

Anna: Eventually, yes. And this matters for the big

question everyone actually wants answered

about Betelgeuse. When is it going to

explode? Because it will. It's an old

massive star, near the end of its life, and

one day it will go supernova and briefly

outshine everything in the night sky. Now,

before anyone emails us, that's expected on a

timescale of up to 100,000 years.

So don't cancel your weekend. But whether a

star has a close binary companion

changes the whole picture. How it sheds mass,

the shape of the gas around it, even the

choreography of the explosion when it finally

comes. Knowing Betelgeuse is a pear

rewrites part of that story.

Avery: And this was direct imaging. An actual

Picture not just an inference from wobbles in

the light.

Anna: That's what makes it land. There had been

circumstantial hints for years, but this is a

direct detection light caught from the

companion itself in the right place at the

right time. It's the difference between the

data suggest a second star and here

it is.

Avery: So if you want to go and look at the star at

the center of all this, Betelgeuse itself.

Where are we? Both hemispheres right now?

Anna: Orion is a pre dawn act. It's climbing

back into the morning sky after being lost in

the sun's glare. For our Southern hemisphere

listeners, Orion rides high in the northern

part of the early morning sky. And it's

upside down compared to the northern view.

Look for Betelgeuse as the bright orange star

from North America and mid northern

latitudes. It's lower in the east southeast

before dawn, climbing higher each week. As we

head towards the northern winter, we'll come

back to it properly in the sky watch. But

next time you find it, just remember it's not

one star. It never was.

Avery: Now from a star that's hiding a companion to

a black hole that was hiding full stop.

Anna, picture, uh, a supermassive black hole.

Where is it?

Anna: Dead center of a galaxy. That's the rule. The

big ones sit in the core.

Avery: That's the rule. And this week, NASA's Swift

observatory helped break it. Astronomers

announced a tidal disruption event. That's

the technical name for a black hole tearing a

star apart and eating it. And the flare it

produced was blazing briefly outshining its

entire host galaxy in ultraviolet. Like

10 billion suns switched on at once. But

here's the thing. It didn't happen in the

middle of the galaxy. It went off about

30,000 light years out from the core.

Anna: 30,000. That's not a rounding error.

That's further from the center than the sun

is from the middle of the Milky Way. That

black hole is out in the suburbs.

Avery: Way out in the suburbs. The event's called

TDE 2025 ABCR

in a Galaxy about 750 million light

years away. And the teams one led out of

NASA and the University of Maryland, another

from UNC Chapel Hill, published it on

27 July in the Astrophysical Journal

Letters. It's the most off center tidal

disruption ever seen. And what it reveals is

a wandering black hole, a around a million

times the mass of the sun, just roaming

through its galaxy, nowhere near the core.

Anna: How does a black hole end up out there? They

don't exactly stroll.

Avery: Best guess is a, uh, galaxy merger. When two

galaxies collide and their central black

holes get thrown together, one can get kicked

out of the middle and left drifting.

Theorists have predicted these wanderers for

years. The problem is they're invisible. A

black hole sitting quietly in the dark emits

no light. You only ever attach one if it does

something dramatic.

Anna: Like grabbing a passing star and lighting up.

Avery: Exactly. The star is the flashbulb. It

wanders too close, gets shredded, and for a

few weeks, the wreckage glows and gives the

whole thing away. That's the only reason we

know this black hole is there at all.

Anna: And there's a lovely modern wrinkle to how

they found it isn't there. This wasn't a

human squinting at plates.

Avery: Not a chance. The sky is too big for that

now. The initial flare was picked up back in

November 2025 by a survey at Palo are

in California that scans the whole northern

sky every couple of nights. It throws up

something like half a million flashes every

single night. So the team trained an AI to

sift that fire hose and flag the ones that

look like a tidal disruption. And it caught

this one precisely because it was in a weird

place off in the outskirts where nobody would

have thought to look. Swift followed up to

nail down the details.

Anna: And that's the taste of what's coming, right?

Once the big new survey telescopes are

running.

Avery: That's the real headline. Under the headline,

with observatories like the Vera Rubin

Observatory and UNC's Argus array coming

online, we go from finding a handful of these

a year to potentially hundreds or thousands.

And suddenly all those invisible wandering

black holes become findable. We're about to

start taking a census of the galaxy's hidden

monsters. And keep swip in mind, by the

Anna: way, because it's going to come back to bite

us later in the show.

Avery: It is. Hold that thought.

Anna: Speaking of survey telescopes about to change

the game, let's talk about one that's now

genuinely nearly on the

NASA's Nancy Grace Roman Space

Telescope, because as of this week, it is

fueled and counting down.

Avery: Fueled. That's a real milestone. That's not a

slide in a presentation. That's propellant in

the tank.

Anna: Precisely. On the 25th of July,

teams at, uh, Kennedy loaded around

290 gallons of hydrazine into

the observatory. That's the fuel it'll use to

hold its position and point with real

precision once it's out there. And NASA is

holding its big mission preview briefing

today, exactly one month out from launch.

The date to circle is the 30th of August

and remarkably, that's about eight months

ahead of the original schedule.

Avery: A NASA flagship running early and as

I understand it, on budget. Let the record

show it can be done.

Anna: It can. And here's why Roman is worth

the excitement. Think of it as a telescope

with Hubble quality sharpness, but a jaw

droppingly wide field of view. Something like

a hundred times the patch of sky Hubble sees

in a single shot. Bass estimate is that in

its first five years, it could image more

than 50 times as much sky as Hubble has

in 30. It's built to survey fast and

wide.

Avery: And what's that actually hunting?

Anna: Two headline jobs. One, dark Energy,

the mystery. Pushing the universe apart

faster and faster. Roman will map how

cosmic structure has grown over billions of

years to pin down what Dark Energy is

actually doing. And two, this is the one

I love. It's an exoplanet machine.

Using a trick called microlensing, Roman

is expected to find more than 100,000

new planets and to catch hundreds of others

in the very act of finding forming around

young stars.

Avery: 100,000. We do a story

most weeks about one interesting new planet

and Roman's going to hand us 100,000.

Anna: It really might reset the whole field.

And this is genuinely for everyone listening

wherever you are. It's a space telescope,

though there's no hemisphere that misses out.

The whole planet shares this one. One

month to go.

Avery: Fingers crossed for the 30th of August.

Right? I told you Swift would come back

around. In story two, Swift was the hero,

the observatory that helped us catch that

wandering black hole. Well, here's the

thing in the tale, Swift itself is in

trouble and the spacecraft sent to save it

is now in trouble too.

Anna: Set it up. Why does Swift need saving in

the first place?

Avery: Because Swift is falling. It's a fantastic

gamma ray and X ray observatory that's been

working since 2004. But it has no

engine of its own, no way to boost its own

orbit, and its orbit has been decaying faster

than expected, partly because heightened

solar activity puffs up the upper atmosphere

and increases the drag. Left alone,

Swift is looking at an uncontrolled re entry

by around the end of this year.

Anna: So it burns up unless someone

goes up and gives it a push.

Avery: Which is exactly the plan. A company called

Catalyst Space Technologies built a

robotics servicing spacecraft named Link.

And NASA hired them for what its own mission

director called a fast, high risk, high

reward rescue. Link launched on 3

July, and the goal is genuinely a first

to fly up, grab hold of Swift, a

satellite that was never designed to be

docked with or serviced and physically

boosted into a higher, safer orbit.

Nobody has ever commercially docked with a

government spacecraft that wasn't built for

it.

Anna: That's ambitious. So what's gone wrong?

Avery: Over the weekend, Link ran into an attitude

control problem and started spinning with its

communications dropping in and out. According

to NASA's update, and I want to be precise

here because this is developing, the

preliminary finding is that two of Link's

three reaction wheels are no longer working

and, and there's some loss of function in its

cold gas thruster system as well.

Anna: Reaction wheels, Those are the spinning

wheels inside a spacecraft that let it turn

and hold steady without using fuel.

Lose those and you lose fine control of which

way you're pointing.

Avery: That's the one. And losing two of three is

serious, especially because there was already

a wobble with one Wheel earlier in

commissioning that they patched in software.

The good news, Link is not lost. It's still

powered, still in contact, and its other

major systems are behaving. The team's plan

is to use Link's electric thrusters, its

xenon propulsion, to stop the spin over the

next few days, then re establish stable

pointing, update the spacecraft's guidance

and navigation to work around the dead

hardware, and only then sit, uh, down with

NASA and decide whether it's still safe to

attempt the approach and capture of Swift.

Anna: So the rescue isn't canceled, it's on

hold while they figure out if the rescuer can

still do the job.

Avery: That's exactly it. And I'll flag for

everyone. This is a life situation as of when

we're recording. By the time you hear this,

the team may already have stopped a spin or

the picture may have changed again. But step

back and look at the shape of it. The same

little observatory that just helped us find

an invisible black hole halfway across the

universe is now clinging on in low Earth

orbit, waiting to see if its own lifeboat can

limp over and give it a shovel. Space is

hard. Even the rescue missions need rescuing.

Anna: We'll keep you posted as that one develops.

And that brings us to the sky over the next

few nights. And there's one thing you cannot

miss, because it's going to be lighting up

the whole night. The moon.

Avery: The full buck moon.

Anna: The full buck moon. Full tonight, the

29th, and near enough to 100%

lit for a couple of nights either side.

Gorgeous to look at as it climbs the eastern

sky after sunset. But it is a

floodlight and that shapes everything else we

can and can't

Avery: do this week, starting with the meteors,

because there are three showers on the go at

once.

Anna: There are. And this is where our two

hemispheres genuinely differ. The headline

shower right now is the Southern Delta

Aquarius, peaking over the next couple of

nights. And the clue is in the name of. For

our Southern Hemisphere listeners, this one's

yours. The radiant over near the bright star

Fomalhaut rides high almost

overhead in the pre dawn hours. So from

Australia, New Zealand and southern Africa,

you're in the best seats on Earth for it.

And for the north, from North America,

it's lower and stingier, though observers

in the southern United States still get a

fair look. Best window everywhere is

the couple of hours before dawn. But

big caveat, this year, that brilliant

moon is going to wash out most of the faint

Delta Aquarids. So temper expectations.

Avery: If the faint ones are drowned out, what's

worth staying up for?

Anna: The fireballs. The Alpha Capricornids

are active at the same time. They're sparse,

only a handful an hour. But they specialize

in slow, brilliant fireballs bright enough

to punch through moonlight. And unlike the

Delta Aquarids, the Capricornids play

fair. They're just as good from either

hemisphere. So the tip for everyone this

week, don't chase quantity. Get

comfortable, be patient and wait for

one big slow fireball to make your

night.

Avery: And the shower, everyone's really waiting for

the Perseids.

Anna: And here's the good news to hold onto.

They're building now, but they peak on the

night of the 12th into the 13th of August.

And this year the timing is close to perfect.

The peak lands right on the New Moon.

Dark skies, no moonlight.

Potentially the best Perseids in years.

They favor the northern Hemisphere, but mid

southern latitudes will catch some too. Mark

it. The night of 12 August is the one to

keep clear.

Avery: And that same date is a big one for another

reason.

Anna: It is a, uh, total solar eclipse on

12 August, with the path of totality

crossing Greenland, Iceland and slice of

Spain, and a partial eclipse visible across

much of Europe and parts of North America.

We'll have full timings closer to the day.

And the one rule that never changes

wherever you are, never look at the

partial phases of a solar eclipse. Without

certified eclipse glasses, ISO

123122

or a properly filtered telescope.

Ordinary sunglasses will not protect your

eyes. That safety line stays in.

No exceptions.

Avery: One quick planet note before we wrap the sky.

Anna: Yes, say goodbye to Jupiter for a

little while. Today the 29th

Jupiter reaches solar conjunction. It's

passing almost directly behind the sun from

our point of view, so it's lost in the glare

and out of action for the next few weeks.

It'll creep back as a pre dawn object

later in August. And for early risers,

Mercury is putting on its best morning

showing of the season, low in the pre dawn

east,

Avery: and we have to close the loop on our lead

story.

Anna: We do. If you're up before dawn chasing

those meteors, look for Orion climbing in

the east and find Betelgeuse, that bright

orange shoulder from the southern hemisphere.

It's high in the northern sky and flipped

over from the north. It's lower in the east

before sunrise. Either way, give it a nod.

You now know something about that star that

nobody knew for a hundred years.

It's got a companion before we go,

Avery: a bit of proper news from our end. We've just

launched the brand new home for the show

astronomydaily.

Anna: Uh, IO same

address you already know, but it's had a

complete makeover and there's a lot there.

Now you can stream the entire back catalog

every episode. There's a news feed that

updates continuously through the day so you

can keep up with the latest space and

astronomy headlines between episodes. You can

read listener reviews and leave one of your

own. And you can sign up for uh, our daily

Space News newsletter to get it all straight

to your inbox.

Avery: And there's a spot to drop us a line,

questions, suggestions, a story you think

we've missed, or just to say good day, we

read them.

Anna: It's brand new, so we genuinely love your

feedback on it. Head to astronomydaily

IO have a wander around and tell us what you

think, what you love, what you change. Help

us make it yours.

Avery: That's astronomy daily for Wednesday, 29th of

July. Betelgeuse's Hundred Year Secret

A black hole in the wrong part of town, Roman

on the clock and a rescue mission holding its

breath.

Anna: Thanks for spending part of your day with us.

Look after each other and whichever

hemisphere you're in.

Avery: Clear skies.

Betelgeuse Is Not Alone!

In this episode

Key Takeaways

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