this post was submitted on 05 Sep 2026
41 points (97.7% liked)

Ask Science

17667 readers
148 users here now

Ask a science question, get a science answer.


Community Rules


Rule 1: Be respectful and inclusive.Treat others with respect, and maintain a positive atmosphere.


Rule 2: No harassment, hate speech, bigotry, or trolling.Avoid any form of harassment, hate speech, bigotry, or offensive behavior.


Rule 3: Engage in constructive discussions.Contribute to meaningful and constructive discussions that enhance scientific understanding.


Rule 4: No AI-generated answers.Strictly prohibit the use of AI-generated answers. Providing answers generated by AI systems is not allowed and may result in a ban.


Rule 5: Follow guidelines and moderators' instructions.Adhere to community guidelines and comply with instructions given by moderators.


Rule 6: Use appropriate language and tone.Communicate using suitable language and maintain a professional and respectful tone.


Rule 7: Report violations.Report any violations of the community rules to the moderators for appropriate action.


Rule 8: Foster a continuous learning environment.Encourage a continuous learning environment where members can share knowledge and engage in scientific discussions.


Rule 9: Source required for answers.Provide credible sources for answers. Failure to include a source may result in the removal of the answer to ensure information reliability.


By adhering to these rules, we create a welcoming and informative environment where science-related questions receive accurate and credible answers. Thank you for your cooperation in making the Ask Science community a valuable resource for scientific knowledge.

We retain the discretion to modify the rules as we deem necessary.

For answers to historical questions, please check out our sister community: !askhistorians@lemmy.world


founded 3 years ago
MODERATORS
 

Has it already happened?

all 6 comments
sorted by: hot top controversial new old
[–] frongt@lemmy.zip 18 points 1 day ago

It has certainly happened. We know of stars that are younger than humans.

But has someone directly observed this happening? Well, it depends. As already noted, star formation takes a long time. It's not like dark, cold dust suddenly collapses and ignites into a star. During the formation process, the dust is compressed, and as you might recall, as volume decreases on a mass, pressure and temperature increase. As it heats up, it starts emitting radiation. So it's possible to observe this even before becoming a true main sequence star. And we have definitely observed a lot of those, and if you go outside and point your sufficiently powerful telescope in the right direction, you too can see one with your own eyes!

https://astronomy.stackexchange.com/questions/49792/has-the-birth-of-a-new-star-ever-been-observed-scientifically-speaking

[–] Kyrias@lemmy.ca 15 points 1 day ago* (last edited 1 day ago)

Yes. New stars are still being born. We can also see stars going supernova that we couldn't see with our bare eyes before.

[–] Catalyst7985@lemmy.zip 9 points 1 day ago (1 children)

Yes, it has already happened. When you look.up the sky, you are pretty much looking at ghosts. Due to the speed of light being finite.

[–] Kolanaki@pawb.social 7 points 1 day ago* (last edited 1 day ago) (1 children)

Well yeah, but I mean has there been or could there be a time where someone actively looking at the sky sees a new star appear before their eyes and it wasn't a super nova of a star dying or a newly formed star relatively nearby? IE the star has been there longer than Earth existed, but it is so far away it took until today to finally arrive where we could see it.

I know it has limited speed, but does it have a limited range before it would just always be invisible beyond a certain range based on size and luminosity, like a flashlight? I am ptetty sure atmosphere has something to do with that, but not 100% certain if light could travel in a vaccum forever.

[–] bjoern_tantau@swg-empire.de 9 points 1 day ago

We know of old supernovae because ancient astronomers catalogued them as new stars (nova means new). Maybe they also managed to find new stars.

The new Vera C. Rubin Observatory should help us with finding new stars and other objects. It will scan the whole southern night sky in three days, marking all changes when it gets to the same patch of sky again.

If sharks have a culture they might have recorded the appearance of Polaris, the north star. Sharks have been longer on earth than Polaris has existed.