How physically realistic are very close binary stars/planets?

[DjVortex]

Binary star systems, where the two stars are really close to each other, seem to be relatively common in the game. Like really, really close to each other. In some cases there's perhaps only a star's diameter distance between them. (In fact, I once jumped to such a star system and the other star just happened be on the way, and I literally flew through that star. I was lucky I got out of there alive. I have video of it and all.)

Perhaps not as common, but still relatively common are binary planets or moons, or planet/moon pairs, where the bodies are really, really close to each other (again, perhaps with just a planet's diameter distance between them). In fact, there's one system (near Sol, I think, I can't remember exactly) where there's a planet with a moon orbiting it so close that it takes like less than a minute for it to go around the planet. There are many examples where two planets/moons are about the same size, and very close to each other.

But how physically realistic is this? Can two stars be really that close to each other, in a stable orbit for millions/billions of years? Or two planets/moons. (I suppose a really small moon could be orbiting an atmosphereless planet very close and be stable, but in this case we are talking about planet/moon pairs that are about the same size.)

I don't think "it's just a game, don't expect realism in it" is a satisfactory answer, given that the game takes pride in modeling the Milky Way 1-to-1 as accurately as possible, using all the information we currently have about star systems in our galaxy.

 

[fennster]

Can't speak for the majority of this, but the moon that orbits in less than a minute is Mitterand Hollow and is indeed an error in the stellar forge. However it was much loved and Frontier decided to leave it in the game as an oddity to visit.

(Also, something, something, roche limit.)

 

[metatheurgist]

As long as the orbits are fast enough it's not impossible but what would be happening is one star should be devouring the other and it should look more spectacular.

Source: https://www.youtube.com/watch?v=_1QXeEtBCSY

 

[Northpin]

I don't think "it's just a game, don't expect realism in it" is a satisfactory answer, given that the game takes pride in modeling the Milky Way 1-to-1 as accurately as possible, using all the information we currently have about star systems in our galaxy.

But it should be a satisfactory answer.
They indeed attempted to model the Milky Way, but still, StarForge cannot be very accurate and/or it had a lot of glitches when it generated the galaxy
Some were probably corrected, but only when mostly visible - as in the Bubble, but even in the bubble some were left unchanged - the most famous example being Mitterand Hollow

There are people that specifically hunted StarForge glitches. For example it was a thread that i cannot seem to be able to find now where a commander was hunting systems having bodies with very peculiar orbits.

But there are all sorts of glitches, from peculiar orbits to peculiar temperatures, atmo pressure, etc.

 

[Ian Doncaster]

Binary star systems, where the two stars are really close to each other, seem to be relatively common in the game. Like really, really close to each other. In some cases there's perhaps only a star's diameter distance between them. (In fact, I once jumped to such a star system and the other star just happened be on the way, and I literally flew through that star. I was lucky I got out of there alive. I have video of it and all.)

Contact Binary systems exist, but the gas transfer between the two stars isn't modelled in Elite Dangerous. (Pity, as it'd look very impressive close-up)

Perhaps not as common, but still relatively common are binary planets or moons, or planet/moon pairs, where the bodies are really, really close to each other (again, perhaps with just a planet's diameter distance between them). In fact, there's one system (near Sol, I think, I can't remember exactly) where there's a planet with a moon orbiting it so close that it takes like less than a minute for it to go around the planet. There are many examples where two planets/moons are about the same size, and very close to each other.

The one with the minute's orbit is a bug in a hand-placed system where they entered the orbital period in the wrong units, which "we" wouldn't let them fix once it was spotted because it was more fun that way. It is entirely unrealistic.

Close orbiting objects more generally are subject to Roche Limits - at some point the gravitational differential from one side of the object to another is larger than its own integrity, and it breaks up into fragments. Ring systems are often thought to form this way after a moon gets too close to a much larger planet and shatters. I'm fairly sure that Roche Limits aren't modelled in Elite Dangerous and therefore some of the binary systems are much closer than they should be - though they have long since fixed the ones that were so close they ended up passing through each other.

Equally, the galaxy does sometimes contain weird stuff - the World of Death is a planet orbiting exceptionally close to a White Dwarf star (mostly inside the exclusion zone!) which you'd think would be impossible and is just a system generation glitch ... but a couple of years after we found it in-game, astronomers found a similar real planet (different size and orbital pattern, but similar mean orbit radius) - so a lot of the strange things are entirely possible.

 

[Navigare Necesse Est]

It IS a game though and the buggy stuff is the flavour on the cake. It's the rare outliers that make the peculiarities and sights to see in a sea of 400 bn more or less bland star systems.

 

[DjVortex]

On that note, is it possible for your ship to get destroyed when jumping to a binary star and ending up inside (or way too close to) the other star? And if that's so then, ostensibly, there's no way to predict or prevent that from happening?

As mentioned, I already had one very close call (literally flying through a star). I'm wondering if I was lucky and didn't get destroyed.

 

[Navigare Necesse Est]

On that note, is it possible for your ship to get destroyed when jumping to a binary star and ending up inside (or way too close to) the other star? And if that's so then, ostensibly, there's no way to predict or prevent that from happening?

As mentioned, I already had one very close call (literally flying through a star). I'm wondering if I was lucky and didn't get destroyed.

Never heard of it - must be extremely rare. Like a couple in 400 bn.

 

[Ian Doncaster]

On that note, is it possible for your ship to get destroyed when jumping to a binary star and ending up inside (or way too close to) the other star? And if that's so then, ostensibly, there's no way to predict or prevent that from happening?

Yes, but it'd be incredibly rare.

You won't end up inside the star once the hyperspace sequence completes - you'd be moved to the edge of the exclusion zone. From there, you should almost always be able to either enter supercruise and get away, or pick a star that's not blocked by either of the pair to hyperspace away to.

You could in theory end up in a situation where supercruising just ended up bouncing you between two exclusion zones, and there were no stars in range and suitable direction to hyperspace to, and so escape was literally impossible; more likely (though still very rare) you'd end up in a situation you could escape from but your ship melts before you manage to find it.

For mitigations:
- 100% reliable but incredibly tedious: check the star classes of the system on the galaxy map before jumping, never jump to a system with more than one star (if you've already had such a close call that your ship is nearly dead already, you might need to do this as far as the nearest repair station)
- good enough that stories of this actually getting someone directly are virtually unknown: make sure you carry a heatsink launcher and keep at least your FSD and Engines subsystems in good repair (with power priorities set so that they can both run even if the rest of your ship fails) so that if you do end up somewhere tough, you can get out of it again.

Heat damage alone - even from being trapped between two binary stars - will take a while to kill a ship, and each heatsink will stop the damage for a while, so a full launcher should always be enough to get out of trouble. Basic manufactured materials can be used to synthesis heatsinks if you need more - stock up on a few before you leave on a long trip.

 

[Brrokk]

Binary star systems, where the two stars are really close to each other, seem to be relatively common in the game. Like really, really close to each other. In some cases there's perhaps only a star's diameter distance between them. (In fact, I once jumped to such a star system and the other star just happened be on the way, and I literally flew through that star. I was lucky I got out of there alive. I have video of it and all.)

Perhaps not as common, but still relatively common are binary planets or moons, or planet/moon pairs, where the bodies are really, really close to each other (again, perhaps with just a planet's diameter distance between them). In fact, there's one system (near Sol, I think, I can't remember exactly) where there's a planet with a moon orbiting it so close that it takes like less than a minute for it to go around the planet. There are many examples where two planets/moons are about the same size, and very close to each other.

But how physically realistic is this? Can two stars be really that close to each other, in a stable orbit for millions/billions of years? Or two planets/moons. (I suppose a really small moon could be orbiting an atmosphereless planet very close and be stable, but in this case we are talking about planet/moon pairs that are about the same size.)

I don't think "it's just a game, don't expect realism in it" is a satisfactory answer, given that the game takes pride in modeling the Milky Way 1-to-1 as accurately as possible, using all the information we currently have about star systems in our galaxy.

I believe it's realistic to have close binaries, but the stars should be pulled out of round shape into eggs.

What the game really gets wrong IMO is planetary rings. Those just shouldn't exist for any planet near another major body; they should be ripped away by tidal forces. There are also reasons to think they'd be short-lived features which is why only Saturn has spectacular rings in our solar system, and rings larger than Saturn's should be very unlikely.

 

[Walter2]

I expect the algorithms FD designed are far simpler than anything the universe has on offer. Weren't there stories of planets growing hair when the Odyssey planetary generation software was pushed too far?

 

[Navigare Necesse Est]

There is no algorithm that can recreate the real galaxy, only approximations.

 

[Navigare Necesse Est]

And it's a commercially used algo for employment in a video game. What do people expect?

 

[Walter2]

There is no algorithm that can recreate the real galaxy, only approximations.

Although there is the possibility that we're all inside a simulation of the galaxy that's running in a supercomputer sitting on someone's desk.

That possibility would explain a lot.

 

[varonica]

Perhaps not as common, but still relatively common are binary planets or moons, or planet/moon pairs, where the bodies are really, really close to each other (again, perhaps with just a planet's diameter distance between them). In fact, there's one system (near Sol, I think, I can't remember exactly) where there's a planet with a moon orbiting it so close that it takes like less than a minute for it to go around the planet. There are many examples where two planets/moons are about the same size, and very close to each other.

The Earth/Moon Roche Limit is actually smaller than the diameter of the earth at just over 11,000klms, so it is indeed possible to have planets, solid ones with a high level of integrity....not mushy balls....be very close to each other in a binary orbit. Mitterand Hollow has been explained by others already.

 

[Navigare Necesse Est]

Although there is the possibility that we're all inside a simulation of the galaxy that's running in a supercomputer sitting on someone's desk.

That possibility would explain a lot.

Dream on, you're all just figments of imaginations and I exactly knew you would say that. At least subconsciously.

 

[Edelgard von Rhein]

Actually getting killed in the circumstances you jump describe has never happened that I have heard of but it is theoretically possible, as you can arrive inside the fuel scoop zone of a secondary star and be immediately gaining heat. I believe there is some code that is supposed to stop you actually arriving inside a celestial body's exclusion zone.

I recently ran a race, The Trouble With Triples https://forums.frontier.co.uk/threa...th-triples-12th-to-20th-november-3308.610240/, where the waypoints are triple star systems with at least two of the components close enough that you can jump through one of the other stars on arrival. The regulation build (an unengineered diamondback scout) had a single heat sink launcher but it was not needed by anyone at the moment of arrival that I saw, as you can get clear of the stars quickly. It was needed partly to help with fuel scooping and because I was asking the entrants to scan installations that were orbiting inside the fuel scooping zone in one system, where they could sometimes be found in between two close-orbiting stars!

Mass transfer between stars is a complex subject and as nice as it would be to have it, especially where one body is a compact object, I can understand why it is not done, nor on the road map.

 

[Sylveria]

If you're expecting "realism" from the game, you're going to be seriously disappointed.

When you can fly right up to a black hole and take not a lick of damage... what does that tell you about the rest of the game?

 

[Sapyx]

It used to happen far more often - people would jump into "contact binary" systems, find themselves buried deep inside the second star, and insta-die from the heat.

The FSD has since been reprogrammed; it's now supposed to always dump you outside of the drop-out radius of any star in the system.

However, just because you're outside the drop-out radius, it might still get real hot, real quick, if your ship happens to arrive in between the two stars. So jumping into a contact binary can still cause damage and kill, only it happens more slowly now, and shouldn't kill you - unless you're in the habit of going AFK during hyperspace jumps.

Yeah, AFK-jumping has killed me, twice. Takes less than five minutes between arrival and ship-go-boom.

But back to the OP's question: yes, out there in the real world universe, there are plenty of stars with very, very close orbits around each other. In astronomy they are often manifested as "spectroscopic binaries" - stars that look like just one single star in even our best telescopes, no matter how much we magnify it, but whose light spectrum clearly shows the characteristic Doppler Effect "wiggling" of two different stars moving back and forth over a period of several hours to several days. There are currently 3722 entries in the Spectroscopic Binary (SB) star catalogue. 40 of those 3722 stars are eclipsing binaries, so we have more direct evidence of the binary nature of those star systems, which helps us calibrate and interpret the observations of the remaining stars, so we often have a pretty good idea of the composition and arrangement of these star systems, even without direct photographic evidence.

For planets and moons, the Roche Limit does enter the calculations when generating star systems in ED using the Stellar Forge algorithms. Moons that are generated "too close" to their planets get blown up and turned into rings instead Of course, we never get to see this "blowing up", since it all happens in the synthetic pseudo-history created by the Stellar Forge, rather than in actual game. Binary planets tend not to form very close to each other, though there may be some extreme cases that the Forge pops out. I seem to recall they had to tweak the Forge in early versions of the game because people were finding gas giant planets orbiting T Tauri stars so close, the two objects had merged into each other. I should point out, that "close planets and moons" seem to be more common in younger star and protostar systems, perhaps reflective that they didn't get as much time cooking in the algorithm before reaching their "final" form and so were more likely to end up with unstable, unrealistic orbits.

 

[Dillon Fallon]

It's worth remembering that nothing is truly stable in the cosmological scale. Stars and planets that look like they're about to crash into each other have every chance that their orbits are just a slow dance before they do collide.

On that note, is it possible for your ship to get destroyed when jumping to a binary star and ending up inside (or way too close to) the other star? And if that's so then, ostensibly, there's no way to predict or prevent that from happening?

As mentioned, I already had one very close call (literally flying through a star). I'm wondering if I was lucky and didn't get destroyed.

Source: https://youtu.be/ihpBhAL8Z_w

Seems you'll be fine and it wasn't just a one off bit of luck. Well, the ship will be fine. I make no guarantees about the state of anyone's underwear, especially if you're in VR.