The star Rigel

[Hominid Mk II]

It's high time I asked yet another awkward question highlighting the embarrassing discrepancies between BT star maps and those in the real world, so...

We know that the star Rigel (Beta Orionis) exists in the BT universe as it does in the real one, because the guy who originally discovered what would later be named the Tanis system worked for an organization called the Rigellian Collective. But the star itself has never appeared on a BT star map.

By my very crude reckoning it should appear something like 200 light years below Argus in the Taurian Concordat.

Can anybody else do better? Please?

[Jaim Magnus]

Just because there is a Rigelian Collective, does not mean such a group MUST be based on Rigel. It could simply be a name.

The Battletech starmaps were never, to my knowledge, meant to be 100% real world accurate. The maps were there to give context to stompy robots.

If, for some reason, you NEED Rigel to be in the Taurian Concordat for your game, then simply put, it is.

[marauder648]

Aye, its like the Canopians, problem is Canopus itself is a massive and massively hot/radioactive star that would have steralized its solar system with heat and radiation. Not a place you want to set  up shop.  They could have gone to another system and gone "This is Canopus now."

[RoundTop]

Some things to remember: 
#1) The IS Map is very simplified as it is 2D, not on a sphere.
#2) The IS Map only shows inhabited systems. This means that if it is on the map, it has people (perhaps not many, but there are people).

This can be seen a lot if you look at the 1SW maps compared to the 3SW maps, as many systems disappear due to being nuked to the stone age and beyond (and a few because Comstar wanted to hide them).

[Frabby]

I think it's safe to say that all real-world stars exist in the BattleTech universe. But Kearny-Fuchida geodesics result in a 2-d "starmap"/jump map that is sometimes radically different from what you see in 3-d realspace. Just roll with it.

[Tai Dai Cultist]

Two suggestions for reconciling real world stars not being in the right place on a BTU map:

A) systems in the BTU are by convention normally named after the inhabited planet rather than the star itself.  The system labelled Rigel (or Canopus, or Betelgeuse, or Rasalhague, etc) on the BTU map may actually only have that name because the colonized planet was, for whatever reason(s), named after a star the colony doesn't actually orbit.

B) It's of considerable note that the maps of the BTU are two dimensional "navigational charts" rather than true three dimensional star maps.  Thanks to the magic of Kearny-Fuchida physics, perhaps any given star is actually reachable via hyperspace jump as if it were physically located as it is on the BTU map rather than it's conventional/real location relative the other stars of the galaxy.

[cray]

I preferred the explanation that the maps are broken (but good enough for game play), not that K-F drives somehow compress a sphere 1000+ light-years in diameter to a 2D depth. After all, if you can compress thousands of light years in one direction to zero distance, then you can do that for others and then the staple 30-light year range of KF drives is meaningless.

[Ruger]

Or it could simply be that the stars' positions in the BTech universe (as well as their size and lethality in some cases) are simply not the same as in our own, real-world universe...kind of like in Sliders...

Ruger

[Liam's Ghost]

Rigel is a big, hot star not likely to support life. We've got too many of those inhabited already!  :P

[glitterboy2098]

Two suggestions for reconciling real world stars not being in the right place on a BTU map:

A) systems in the BTU are by convention normally named after the inhabited planet rather than the star itself.  The system labelled Rigel (or Canopus, or Betelgeuse, or Rasalhague, etc) on the BTU map may actually only have that name because the colonized planet was, for whatever reason(s), named after a star the colony doesn't actually orbit.

Star Trek has the same issue.. their "Rigel" is located in a totally different place than the Star Rigel known IRL. whats worse, trek has evidence that the latter still exists, in its normal spot. this has led some people to speculate the other 'Rigel" is actually just a coincidental alien name. (sorta like the Centauri Empire in babylon 5)

in battletech, perhaps any planet named "Rigel' might be named by trekkies.

Canopus was a mythological navigator (the star was named after that figure) so that might be a source of that name, or perhaps the egyptian town named after him. (though the irony of the capitol world of a matriarchy being named after a Male Spartan Warrior..)

Betelgeuse and Rasalhague would be harder to justify..

[marauder648]

Betelgeuse and Rasalhague would be harder to justify..

Yeah its kinda hard to mix up Betelgeuse with anything else considering its bloody HUUUUUUUGE (to the point that even today, we can detect sun spots on its surface that are considerably bigger than our sun).  Whilst Rasalhague is apparently a binary which I didn't know :) as well as being another very large, bright star.

Still its not like we've got out to VY Canis Majoris and have somehow mis-labelled a 1 billion+ KM death orb :p

[Hominid Mk II]

I preferred the explanation that the maps are broken (but good enough for game play), not that K-F drives somehow compress a sphere 1000+ light-years in diameter to a 2D depth. After all, if you can compress thousands of light years in one direction to zero distance, then you can do that for others and then the staple 30-light year range of KF drives is meaningless.

Uh, broken? How, exactly?

BTW, Cray, as you're here... did you have any particular real-world star in mind as being the one that the slowboat colony Columbia orbits?

[cray]

Uh, broken? How, exactly?

Not being 3D.

BTW, Cray, as you're here... did you have any particular real-world star in mind as being the one that the slowboat colony Columbia orbits?

Something close to Sol, less than 20 light-years away. I don't recall getting more specific than that.

[Hominid Mk II]

Something close to Sol, less than 20 light-years away. I don't recall getting more specific than that.

Sigh! Oh, well...!

[Major Headcase]

Maybe FASAs astronomy consultant from NASA was sick that day??  ::)

[skiltao]

the guy who originally discovered what would later be named the Tanis system worked for an organization called the Rigellian Collective
<snip>
By my very crude reckoning it should appear something like 200 light years below Argus in the Taurian Concordat.

I'm not familiar with a place called Argus in the Concordat, but Beta Orionis should be in the vicinity of Betelgeuse and Cursa, yeah? Which puts it somewhere around Andurien or in the nearby half of the Magistracy.

The Collective, though, could be named for Rigil Kentaurus, which is marked on BT maps. (Which might also explain the odd Star Trek placement.)

[jimdigris]

As I understand it, FASA didn't have any real star maps that went out beyond a few dozen light years. So, they took a map of Wisconsin and made it into the Inner Sphere star map and superimposed the names of the major systems over existing cities and towns in Wisconsin.  The problem with the astronomical maps of the time is that they were made for star gazers, who needed the distance above the horizon and positions relative to other stars.  "Road maps" and distances from Earth weren't useful and seldom published.  I know of just one book that has something like a road map and that may have been published after FASA's map.

[skiltao]

Meh. I grabbed a copy of the Bright Star catalogue a couple years ago. We should be able to find a star's distance in light years by dividing 3.26 by the parallax arc seconds, right?



It's pretty good out to 75LY, but after that they spread out, and it's not all that much better than the distances shown on BattleTech's maps. (Apparently distances greater than 326-ish LY were going to be a little random anyways, due to the limits of ground based telescopes.)



Looking at the big clump of stars from 0LY to 300LY, you can see a general drift downwards, which is what we'd expect if the stellar positions were being projected onto a flat plane.

[Hominid Mk II]

I'm not familiar with a place called Argus in the Concordat, but Beta Orionis should be in the vicinity of Betelgeuse and Cursa, yeah? Which puts it somewhere around Andurien or in the nearby half of the Magistracy.

Most people would automatically assume that, on the basis of what seems like common sense to everyday human experience. But for the benefit of anybody reading this who doesn't read popular science magazines: a lot of our notions of common sense break down when you come to astronomy! Stars that we place in the same constellation because they seem to be near to each other when we look at them in our sky are hardly ever anywhere near each other in reality. Obviously they are in the same direction or they wouldn't even appear to be near each other, but they're usually very different distances away from us and therefore also very different distances from each other. Alpha Centauri (or Rigil Kentarus, or Toliman) is only 4.37 light years away from us (making it the nearest star after Sol), but Beta Centauri (or Hadar, or Agena) is about 390 light years away and Gamma Centauri (or Muhlifain) is about 130 light years away. And that's just three stars out of just one constellation!

I could go on, but I think I've made my point!

[Frabby]

To be very precise, Alpha Centauri is a binary star system 4.37 light-years away from us with a third star around it, the red dwarf Proxima Centauri, making it a trinary star system.

The latter is the actual closest star to Sol (4.25 light-years), but it's very small and not bright enough to be seen. Its rotation period is 550,000 years according to Wikipedia, so it'll be the closest star to us for some time yet.

[skiltao]

Obviously they are in the same direction or they wouldn't even appear to be near each other, but they're usually very different distances away from us and therefore also very different distances from each other.

Even worse, although BattleTech's starmap is pretty good at preserving the direction of a star, it's a lot less consistent about preserving distances. It shows Cursa at about 4x it's actual distance, and Betelgeuse at about 0.4x, for instance. Saiph's in that same patch of sky too, and BattleTech's map shows it about 69LY from Terra instead of 650.

Multipliers above 1.5x seem to be an aberration, though, and my best guess is that Rigel is in the 0.4x to 0.8x range.

[SCC]

My personal best explanation for this is that BT is actually a link based system and NOT a simple range one, meaning that there are a limited number of stars that you can jump too from any given star. Now this list is NORMALLY those within 30 ly, but not always, resulting in situations like this where we get stars too close or too far away.

Further more this can be used to explain the clusters with numbers such as the item "Pleiades Cluster (100)" that appears on the maps, there's actually a star there called Pleiades but in-addition to the all the system you can normally jump to from there there are other systems you can jump to that you wouldn't normally be able to and the only way in or out of this group of 100 systems is through this Pleiades system. This of course begs the question of how these 'other' routes are known about/discovered to which the answer is some sort of scientific survey process last carried out sometime before the formation of the Star League for most systems. This means that there are most likely other clusters and links waiting to be discovered.