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First pictures from Euclid satellite reveal billions of orphan stars

nottingham.ac.uk

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Re: First pictures from Euclid satellite reveal billions of orphan stars

#71

Post by neamar »

pavel_lishin wrote: post #53
gcanyon wrote: post #39

The stars near us in the Milky Way are tens of light years away, and we’ll have to do some incredible science and technology to visit them. How much worse would it be if you were an intelligent life form on a planet orbiting one of those orphans, and the nearest star was a thousand, ten thousand, even a million light years away?

There is a novel written with that premise as the background! I can share the title with you, if you'd like - that particular premise is a very small part of the novel.

I'd like to read it!

Re: First pictures from Euclid satellite reveal billions of orphan stars

#72

Post by raverbashing »

SJC_Hacker wrote: post #49
recursive wrote: post #46

Earlier quoted context omitted.

I suspect in any solar system, the mass of the non-stars are a rounding error compared to the whole system's mass.

> I suspect in any solar system, the mass of the non-stars are a rounding error compared to the whole system's mass. A brown dwarf orbiting a red dwarf would beg to differ.

Which are both "low mass" compared to other stars out there

It might even be possible to have this combination weigh less than our sun

Re: First pictures from Euclid satellite reveal billions of orphan stars

#73

Post by martinpw »

Ringz wrote: post #30
PeterCorless wrote: post #20

We can spot the orphan stars at this distance. However, Euclid needs to turn to closer targets than the Pegasus cluster to spot rogue planets. https://www.theguardian.com/science/article/2024/may/23/eucl... . In this case, it found dozens of rogue planets in the Orion nebula, which is only 1,500 ly away. I am presuming there are also going to be great numbers of rogue planets in deep space, not tied to any star or ga…

It would be interesting to calculate how much these stars contribute to the mass deficit of the universe.

Probably not that much relatively.

Specifically the Perseus cluster reported on here has a mass of around 10^15 solar masses in total. Of that ~10% is in the form of stars, 20% is intergalactic gas and the remainder is dark matter.

The report here says 1.5 trillion of these stars in this cluster which is ~10^12 solar masses (assuming average star mass is similar to the sun's.)

So the newly observed stars reported here are around 0.1% of the total cluster mass, or around 1% of the total mass of stars in the cluster. All very approximate of course.

Re: First pictures from Euclid satellite reveal billions of orphan stars

#74

Post by alenrozac »

whimsicalism wrote: post #28
rob74 wrote: post #18

Earlier quoted context omitted.

The long scale is far from just a novelty, most European countries other than the UK use it. Actually I thought it was used in all non-English-speaking countries, but Wikipedia showed me that the situation is far more complicated than I thought: https://en.wikipedia.org/wiki/Long_and_short_scales#/media/F... Besides short scale and long scale, there is a sizable "short scale with milliard instead of billion" fraction…

almost all scientific writing i can find from people in portugal uses the short scale. english formal communication has standardized around the short scale

All scientific writing in Slovenia uses long scale. I've heard it being used in EU institutions too.

Re: First pictures from Euclid satellite reveal billions of orphan stars

#77

Post by withinboredom »

dwaltrip wrote: post #60
wrycoder wrote: post #34

Earlier quoted context omitted.

Tell them it's comparable to $1 bills laid end to end from here to the sun. And tell them it's only 1/35 of the US national debt, which is roughly $350,000 per US taxpayer.

How many Olympic swimming pools is that?

It’s several football fields full of cash.

Re: First pictures from Euclid satellite reveal billions of orphan stars

#78

Post by deprecative »

Retric wrote: post #59
recursive wrote: post #55

Earlier quoted context omitted.

Is the brown dwarf not considered a star? I don't know.

“A brown dwarf is an object which is made of the same stuff as stars, but does not have enough mass for hydrogen fusion (combining hydrogen atoms into helium atoms). Hydrogen fusion is what makes stars glow. Brown dwarfs are not massive enough to do this, so they are not stars. On the other hand, they are not regular giant planets, because they do glow.” https://simple.wikipedia.org/wiki/Brown_dwarf While very young…

The nebulous space the Brown dwarf occupies in terms of classification is fascinating to say the least. I'm a passing not even hobbyist on the subject but that they glow but not like that is really interesting.

When I think of the brown dwarf I am also reminded of the hypothesized black dwarf. This would be the stage after white dwarf. It's hypothesized because it takes longer for the white dwarf bodies to cool than exists presently in the history of the universe. It's only a handful of sentences and will largely repeat the previous paragraph but there's the wiki page for black dwarf.

https://simple.wikipedia.org/wiki/Black_dwarf

Very interesting stuff all around. Space is so fucking cool, y'all.

Re: First pictures from Euclid satellite reveal billions of orphan stars

#80

Post by gcanyon »

FredPret wrote: post #69
gcanyon wrote: post #39

The stars near us in the Milky Way are tens of light years away, and we’ll have to do some incredible science and technology to visit them. How much worse would it be if you were an intelligent life form on a planet orbiting one of those orphans, and the nearest star was a thousand, ten thousand, even a million light years away?

Might be much harder to bootstrap your astronomy in that situation as well. As I understand, we built much of our picture of the universe on the fact that we can do precise parallax measurements of nearby stars. Then we used that to see how far the nearby Cepheid variable stars are, and used the patterns those exhibit to measure distant galaxies. Then at some point we could determine the distance to a certain kind of…

Ooh, this is super interesting! This video by The Science Asylum lays out the "distance ladder" in great detail: https://www.youtube.com/watch?v=zrpdwJNNskk This wikipedia article also lays out the distance ladder: https://en.wikipedia.org/wiki/Cosmic_distance_ladder so if our hypothetical "intelligent species on a planet orbiting an orphan star" were more than 30,000 light years away from the nearest star, they wouldn't be able to measure that distance with accuracy using the technology we have now. That might not apply to ranging whole galaxies? And they could get better with time? In any case, my idea that they might take off for a "nearby" star "only" ~100 light years away because they don't know better is foolish.
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