[HN Gopher] Gemini North telescope discovers long-predicted stel...
___________________________________________________________________
Gemini North telescope discovers long-predicted stellar companion
of Betelgeuse
https://noirlab.edu/public/news/noirlab2523/
Author : layer8
Score : 91 points
Date : 2025-07-22 16:41 UTC (6 hours ago)
(HTM) web link (www.science.org)
(TXT) w3m dump (www.science.org)
| layer8 wrote:
| 1-minute video: https://noirlab.edu/public/videos/noirlab2523b/
| htrp wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| 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.
| bongoman42 wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| We should fix that.
| colechristensen wrote:
| >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.
| pavel_lishin wrote:
| Could this explain why Betelgeuse's brightness seems to vary so
| much?
|
| edit: apparently, yep, that's why.
| arnavpraneet wrote:
| Could you provide any links as to this? Was not able to find
| anything
| layer8 wrote:
| 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".
| dang wrote:
| 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 wrote:
| I suspect the following should work to force the English
| version:
| https://noirlab.edu/public/news/noirlab2523/?nocache=true&la...
| ac794 wrote:
| Gemini also has a press release here:
| https://www.gemini.edu/news/press-releases/noirlab2523
| anjel wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| The 'ghost' on the other side is an artifact of the speckle
| imaging technique.
| mkw5053 wrote:
| 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 wrote:
| 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 wrote:
| Is it Beetlejuice, Beetlejuice?
| carabiner wrote:
| Juice of the beetle, yes.
___________________________________________________________________
(page generated 2025-07-22 23:00 UTC)