frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

Open in hackernews

Gemini North telescope discovers long-predicted stellar companion of Betelgeuse

https://www.science.org/content/article/betelgeuse-s-long-predicted-stellar-companion-may-have-been-found-last
121•layer8•12h ago
https://noirlab.edu/public/news/noirlab2523/

Comments

layer8•12h ago
1-minute video: https://noirlab.edu/public/videos/noirlab2523b/
htrp•11h ago
Gemini North is a telescope, not some new feature of Google's AI model https://en.wikipedia.org/wiki/Gemini_Observatory

>Gemini North telescope in Hawai‘i reveals never-before-seen companion to Betelgeuse, solving millennia-old mystery

dylan604•11h ago
At least they got to see it before Betelgeuse went supernovae. Do we have examples of the results of the companion star when the main star lets go?
dontlikeyoueith•10h ago
Wouldn't all Type Ia supernova be examples of at least one possible end state of such an event?

https://science.nasa.gov/resource/type-ia-supernova/

The larger star explodes first in a Type II supernova, becomes a Type Ia.

dylan604•10h ago
You're asking a question in response to a question. Your Type Ia link suggests this is not what is happening with Betelgeuse though. Its companion star is not a white dwarf. Betelgeuse itself is the start expected to go boom. So what happens to its companion? The anim you linked to shows that the white dwarf's explosion didn't destroy its larger star companion, but Betelgeuse is the opposite with the larger star going boom.
dontlikeyoueith•5h ago
You're misunderstanding.

I'm not saying Betelgeuse would be a type Ia. Betelgeuse will be a Type II supernova.

I'm wondering whether Type II supernovae with smaller partners later become Type Ia once the larger partner explodes and becomes a white dwarf. The former smaller partner then becomes the relatively larger partner that loses mass to the remnant.

bongoman42•9h ago
For all we know, it might have gone supernova in the last few hundred years and we've yet to receive the light from it.
dylan604•7h ago
Betelgeuse is approximately 650 to 700 light-years away from Earth, so if you consider a few 300 then that means we have at least ~350 years to continue studying it.
chasil•11h ago
The companion star "has an estimated mass of about 1.5 times that of the Sun and appears to be an A- or B-type main pre-sequence star, i.e. a hot, young, bluish-white star that has not yet begun to burn hydrogen in its core... The companion is located at a relatively close distance to Betelgeuse, about 4 times the distance between Earth and the Sun. This discovery is the first time a stellar companion has been detected orbiting so close to a red supergiant star. Even more surprising is that the companion orbits inside Betelgeuse's outer atmosphere."
pixl97•10h ago
Also

>This discovery provides a clearer picture of this red supergiant’s life and future death. Betelgeuse and its companion star were likely born at the same time. However, the companion star will have a shortened lifespan as strong tidal forces will cause it to spiral into Betelgeuse and meet its demise, which scientists estimate will occur within the next 10,000 years.

It's unfortunate our flesh lasts but a blink of cosmic time. That would be something to witness.

adastra22•10h ago
We should fix that.
colechristensen•8h ago
>It's unfortunate our flesh lasts but a blink of cosmic time. That would be something to witness.

My preferred solution to the Fermi paradox is that hundred million year long lifespans become trivial relatively soon at which point sublight speed galactic travel becomes no big deal and the differing time scale means that not being contacted by an alien intelligence simply hasn't happened yet, have you tried to establish communication with an ant hill in the last 10 seconds? Everybody else in the galaxy who could talk to us lives so long that they just haven't tried to say hello in the last 10,000 years because they were out to lunch.

ofcrpls•1h ago
https://en.wikipedia.org/wiki/Yuga_cycle
pavel_lishin•11h ago
Could this explain why Betelgeuse's brightness seems to vary so much?

edit: apparently, yep, that's why.

arnavpraneet•11h ago
Could you provide any links as to this? Was not able to find anything
layer8•10h ago
See here: https://en.wikipedia.org/wiki/Betelgeuse#Variability

And from the original NOIRLab link: “This discovery answers the longstanding mystery of the star’s varying brightness”.

jimmytucson•1h ago
The system’s brightness decreases when the companion star swings around behind Betelgeuse. It also dips when Betelgeuse goes behind the companion star but much less so because Betelgeuse is so much larger.
dang•10h ago
The submitted URL was https://noirlab.edu/public/news/noirlab2523/, but for some reason is frequently returning the Spanish version of the article. We replaced it with a link to a third-party article and will include the noirlab.edu link at the top.
layer8•10h ago
I suspect the following should work to force the English version: https://noirlab.edu/public/news/noirlab2523/?nocache=true&la...
ac794•7h ago
Gemini also has a press release here: https://www.gemini.edu/news/press-releases/noirlab2523
anjel•9h ago
dumb question: If a pre-sequence star is assimilated into a larger EOL star, does all the newly assimilated fuel delay or accellerate the larger star's demise?
bonzini•8h ago
It may prolong life by a few million years. A red supergiant's outer layers still have a few solar masses worth of hydrogen, and the extra material would delay the collapse of the star onto its core.

On the other hand, if the merger happens after the star has started burning carbon, it would have no effect. The explosions and collapses occurring in a supergiant are driven by successive phases of nuclear fusion in the core (collapse when one kind of fuel is exhausted, explosion as the previous fusion products become fusion ingredients), and they happen on a very short timescale (starting at thousands of years and ending at days before the star goes supernova). The presence of lighter elements billions of km away would not really have any impact on that.

e23c16•9h ago
The paper is here: https://arxiv.org/abs/2507.15749

The detection appears to be statistically very marginal, 1.5sigma, and the image contains a very similar bright spot on the opposite side of the star (which, for some reason, does not warrant a detection claim).

ac794•7h ago
The 'ghost' on the other side is an artifact of the speckle imaging technique.
mkw5053•9h ago
Wow, so it's currently shining purely from gravitational energy release, not nuclear reactions. I hadn't realized that it was possible or that we'd be able to see something of the sort.
Sharlin•8h ago
This was how physicists hypothesized the sun and other stars work in the late 19th and early 20th century, before the discovery of nuclear fusion. It presented a conundrum because calculations showed that the sun could only sustain the observed rate of energy release for a few million years – whereas the contemporary geological evidence was indicating that the Earth must be billions of years old.
AverageSavage•6h ago
Is it Beetlejuice, Beetlejuice?
carabiner•6h ago
Juice of the beetle, yes.
_spduchamp•2h ago
The sequel wasn't as good.
SirLJ•1h ago
Any comments from Ford Prefect about this?

Qwen3-Coder: Agentic coding in the world

https://qwenlm.github.io/blog/qwen3-coder/
421•danielhanchen•8h ago•147 comments

Mathematics for Computer Science (2024)

https://ocw.mit.edu/courses/6-1200j-mathematics-for-computer-science-spring-2024/
25•vismit2000•1h ago•1 comments

The Benefits of Trunk-Based Development

https://thinkinglabs.io/articles/2025/07/21/on-the-benefits-of-trunk-based-development.html
5•gpi•27m ago•0 comments

Countries across the world see food price shocks from climate extremes

https://www.bsc.es/news/bsc-news/countries-across-the-world-see-food-price-shocks-climate-extremes-research-involving-bsc-shows
16•littlexsparkee•1h ago•1 comments

Show HN: WTFfmpeg

https://github.com/scottvr/wtffmpeg
10•ycombiredd•1h ago•0 comments

Algorithms for Modern Processor Architectures

https://lemire.github.io/talks/2025/sea/sea2025.html
126•matt_d•6h ago•11 comments

More than you wanted to know about how Game Boy cartridges work

https://abc.decontextualize.com/more-than-you-wanted-to-know/
256•todsacerdoti•10h ago•24 comments

Android Earthquake Alerts: A global system for early warning

https://research.google/blog/android-earthquake-alerts-a-global-system-for-early-warning/
227•michaefe•10h ago•68 comments

Why you can't color calibrate deep space photos

https://maurycyz.com/misc/cc/
86•LorenDB•5h ago•48 comments

Swift-erlang-actor-system

https://forums.swift.org/t/introducing-swift-erlang-actor-system/81248
248•todsacerdoti•10h ago•49 comments

We built an air-gapped Jira alternative for regulated industries

https://plane.so/blog/everything-you-need-to-know-about-plane-air-gapped
187•viharkurama•10h ago•115 comments

No Cheese Please

https://www.lrb.co.uk/the-paper/v47/n13/anthony-grafton/no-cheese-please
14•Petiver•1d ago•5 comments

Don't animate height

https://www.granola.ai/blog/dont-animate-height
334•birdculture•3d ago•197 comments

Subliminal learning: Models transmit behaviors via hidden signals in data

https://alignment.anthropic.com/2025/subliminal-learning/
146•treebrained•11h ago•32 comments

I watched Gemini CLI hallucinate and delete my files

https://anuraag2601.github.io/gemini_cli_disaster.html
131•anuraag2601•10h ago•153 comments

TODOs aren't for doing

https://sophiebits.com/2025/07/21/todos-arent-for-doing
313•todsacerdoti•15h ago•178 comments

TapTrap: Animation‑Driven Tapjacking on Android

https://taptrap.click/
46•Bogdanp•5h ago•5 comments

Managing EFI boot loaders for Linux: Controlling secure boot (2015)

https://www.rodsbooks.com/efi-bootloaders/controlling-sb.html
7•CaliforniaKarl•3d ago•0 comments

Gemini North telescope discovers long-predicted stellar companion of Betelgeuse

https://www.science.org/content/article/betelgeuse-s-long-predicted-stellar-companion-may-have-been-found-last
121•layer8•12h ago•30 comments

Show HN: Phind.design – Image editor & design tool powered by 4o / custom models

https://phind.design
49•rushingcreek•11h ago•15 comments

Comparing the Glove80 and Maltron Keyboards

https://tratt.net/laurie/blog/2025/comparing_the_glove80_and_maltron_keyboards.html
46•ltratt•7h ago•21 comments

Font Comparison: Atkinson Hyperlegible Mono vs. JetBrains Mono and Fira Code

https://www.anthes.is/font-comparison-review-atkinson-hyperlegible-mono.html
191•maybebyte•15h ago•127 comments

Firebender (YC W24) Is Hiring

https://www.ycombinator.com/companies/firebender/jobs/yisDXr5-founding-engineer-generalist
1•kevo1ution•8h ago

Many lung cancers are now in nonsmokers

https://www.nytimes.com/2025/07/22/well/lung-cancer-nonsmokers.html
127•alexcos•13h ago•168 comments

Ask HN: What software subscriptions are worth paying for?

4•helloworlddd•13m ago•0 comments

Show HN: Compass CNC – Open-source handheld CNC router

https://www.compassrouter.com
126•camchaney•3d ago•29 comments

Tiny Code Reader: a $7 QR code sensor

https://excamera.substack.com/p/tiny-code-reader-a-7-qr-code-sensor
123•jamesbowman•12h ago•39 comments

Hegel Dust

https://www.bookforum.com/print/3201/hegel-dust-62209
22•pepys•1d ago•4 comments

OSS Rebuild: open-source, rebuilt to last

https://security.googleblog.com/2025/07/introducing-oss-rebuild-open-source.html
151•tasn•15h ago•48 comments

NonRAID – fork of unRAID array kernel module

https://github.com/qvr/nonraid
54•qvr•9h ago•43 comments