The distance of a parsec in the Star Wars galaxy

Mange · Post by **Mange** » 2004-04-12 05:33pm

The word "parsec" has been mentioned a few times in the history of Star Wars. The last time we heard it was in AOTC when Padmé told Anakin that Geonosis was "less than a parsec away". A terrestial parsec is 3.26 light-years (I won't explain further than that, since I guess that those who needs to now enough already does that and my English will get on your nerves if I would try to explain

). It would certainly be different in the Star Wars galaxy. As dr. Saxton points out on standard units in the Star Wars galaxy: (http://www.theforce.net/swtc/units.html):

We don't yet have any way of determining what that measurement is

(please note that the page was last updated 11 June 1999). Two years ago, Inside the Worlds of Episode 1 was released (which, BTW, has the same lesser canon status as the ICS-books for example), and I was fortunate enough to glance inside a copy the other day. There it was, the distance between Coruscant and its sun! The orbital distance is said to be between 207 million and 251 million kilometers (thus giving a mean distance of 229 million kilometers, comparable to the orbit of Mars). Knowing this (and assuming that Coruscant's sun holds about the same mass as ours), I thought it would be fun calculating a "Coruscant parsec", just for the fun of it and to slap a few trekkers. Although having been an amateur astronomer for the last fifteen years, I'm really bad at math. I hold a Masters degree in Social Science, but math has always eluded me somewhat. Knowing the orbital radius, I used simple trigonometry and calculated that a "Coruscant parsec" would be between 4,72 and 5 light-years. Are there some people out there who are better on math than me, and who could make better calculations? Have I overcomplicated things?
Oh, I guess that this perhaps would be better suited in the Pure Star Wars thread, sorry.

General Zod · Post by **General Zod** » 2004-04-12 05:37pm

Dictionary.Com wrote:par·sec ( P ) Pronunciation Key (p?sk)
n.
A unit of astronomical length based on the distance from Earth at which stellar parallax is one second of arc and equal to 3.258 light-years, 3.086 × 1013 kilometers, or 1.918 × 1013 miles.

Tribun · Post by **Tribun** » 2004-04-12 05:41pm

I think, this belongs into "Pure Star Wars"........

HRogge · Post by **HRogge** » 2004-04-12 05:43pm

A parsec is defined by the orbit of your planet around it's sun ( it's radius to be specific ). It's something different for each planet.

Mange · Post by **Mange** » 2004-04-12 05:52pm

HRogge wrote:A parsec is defined by the orbit of your planet around it's sun ( it's radius to be specific ). It's something different for each planet.

Yes, of course. That is what I've pointed out, but the assumption has been made (by dr. Saxton and others) that Coruscant forms the basis for the standard units in the Star Wars galaxy, thus this thread.

Post by **Ghost Rider** » 2004-04-12 06:12pm

Off to PSW

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-04-12 06:17pm

I had previously established what a Standard Parsec was in SW almost a year ago (using the average orbital distance of Coruscant), but the last time I posted it was in HOS, and it's currently in the archived board.

But you're result pretty much matches mine, I think.

EDIT: Found it. Posted 24 April 2003:

I just finished the calculations, and a SW parsec is 4.95 of our light-years, or 1.52 times greater than our parsec (3.26 ly).

Sorry about the lack of math, but I give my word that it's perfectly accurate.

Mange · Post by **Mange** » 2004-04-13 03:33am

Spanky The Dolphin wrote:I had previously established what a Standard Parsec was in SW almost a year ago (using the average orbital distance of Coruscant), but the last time I posted it was in HOS, and it's currently in the archived board.

But you're result pretty much matches mine, I think.

EDIT: Found it. Posted 24 April 2003:
I just finished the calculations, and a SW parsec is 4.95 of our light-years, or 1.52 times greater than our parsec (3.26 ly).
Sorry about the lack of math, but I give my word that it's perfectly accurate.

Great! Almost a year to the date! I hope that some other people could make calculations, but it seems as though your (and mine) calculations are correct, even if I didn't dare to nail it down exactly.

Sarevok · Post by **Sarevok** » 2004-04-13 03:59am

Spanky The Dolphin wrote:I had previously established what a Standard Parsec was in SW almost a year ago (using the average orbital distance of Coruscant), but the last time I posted it was in HOS, and it's currently in the archived board.

But you're result pretty much matches mine, I think.

EDIT: Found it. Posted 24 April 2003:
I just finished the calculations, and a SW parsec is 4.95 of our light-years, or 1.52 times greater than our parsec (3.26 ly).
Sorry about the lack of math, but I give my word that it's perfectly accurate.

Sill there are some problems with this value. Did not Padme say that Genosis is less than a parsec away from Tatoon ? If a parsec is 4.95 light years that seems way too close.

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-04-13 04:01am

So you're saying that there wouldn't be problem if it was only 3.26 lightyears per parsec?

Sarevok · Post by **Sarevok** » 2004-04-13 04:22am

Spanky The Dolphin wrote:So you're saying that there wouldn't be problem if it was only 3.26 lightyears per parsec?

No. The average distanc between two inhabited planets in the SW galaxy should be higher.

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-04-13 04:25am

Well, it isn't. Padme says it is a parsec, so it's a parsec.

ClaysGhost · Post by **ClaysGhost** » 2004-04-13 08:40am

evilcat4000 wrote:
Spanky The Dolphin wrote:So you're saying that there wouldn't be problem if it was only 3.26 lightyears per parsec?
No. The average distanc between two inhabited planets in the SW galaxy should be higher.

I don't think there's any information pointing to a problem. The spread about the average distance (which we don't know) could easily be very large. We ourselves have no idea what the average separation between inhabitable systems in our own galaxy is. Tatooine is a colony anyway, isn't it?

Mad · Post by **Mad** » 2004-04-13 09:50am

evilcat4000 wrote:No. The average distanc between two inhabited planets in the SW galaxy should be higher.

So? The average probably is higher. But that doesn't exclude the possibility that there are a few systems right next to each other. It may seem unlikely, but there's also a lot of stars, so there's lots of chances for such things to happen.

Knife · Post by **Knife** » 2004-04-13 11:07am

evilcat4000 wrote:
Sill there are some problems with this value. Did not Padme say that Genosis is less than a parsec away from Tatoon ? If a parsec is 4.95 light years that seems way too close.

Proxima Centauri 1.30 parsecs

Alpha Centauri A 1.33 parsecs

Alpha Centauri B 1.33 parsecs

Barnard's Star 1.83 parsecs

Wolf 359 2.39 parsecs

So I guess as far as actualy distance is conserned, Geonosis being only a parsec away from Tatooine is not that bad. The only problem I would have is storytelling and continuity. Having two major planets in history that are right next door to each other but only finding out about it after five movies that span roughly 40 years is a bit odd.

Mange · Post by **Mange** » 2004-04-13 12:16pm

evilcat4000 wrote:
Spanky The Dolphin wrote:I had previously established what a Standard Parsec was in SW almost a year ago (using the average orbital distance of Coruscant), but the last time I posted it was in HOS, and it's currently in the archived board.

But you're result pretty much matches mine, I think.

EDIT: Found it. Posted 24 April 2003:
I just finished the calculations, and a SW parsec is 4.95 of our light-years, or 1.52 times greater than our parsec (3.26 ly).
Sorry about the lack of math, but I give my word that it's perfectly accurate.
Sill there are some problems with this value. Did not Padme say that Genosis is less than a parsec away from Tatoon ? If a parsec is 4.95 light years that seems way too close.

On the contrary. The average distance between the stars in the Milky Way galaxy is 3 to 4 light-years (ref. Moore, Patrick The Universe), and we'll have to assume that the Star Wars galaxy has roughly the same properties as a standard spiral galaxy. There is nothing to say that two starsystems with life can't be close to each other.

ClaysGhost · Post by **ClaysGhost** » 2004-04-13 12:26pm

Knife wrote: <some distances>

Careful. Geonosis and Tatooine are separated by about 1 SW parsec, which Spanky has found to be 4.95 light years rather than our corresponding unit of 3.26ly. So to compare it with stars near to Earth, you need to convert your quoted distances to SW parsecs:

Proxima Centauri 0.86 SW parsecs

Alpha Centauri A/B 0.88 SW parsecs

Barnard's Star 1.2 SW parsecs

Wolf 359 1.6 SW parsecs

I wonder what SW's equivalent of a light year is.

Having two major planets in history that are right next door to each other but only finding out about it after five movies that span roughly 40 years is a bit odd.

I don't know. Was there any reason why Geonosis would be mentioned beyond Ep2? Obi Wan wasn't hiding out there. Luke didn't live there. There's no particular reason for it to be mentioned in Ep4-6, no more than we need to know about the other moons of Yavin in Ep4 (for example).

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-04-13 12:28pm

SW light years are virtually the same as ours, only about .05% longer, I think.

EDIT: Okay found out. Since Standard years are three days longer, (368 vs 365), their light years are actually about 1.008 times longer than ours:

RL LY: 9,460,730,472,580 km
SW LY: 9,538,489,901,122 km

Knife · Post by **Knife** » 2004-04-13 12:36pm

ClaysGhost wrote: Careful. Geonosis and Tatooine are separated by about 1 SW parsec, which Spanky has found to be 4.95 light years rather than our corresponding unit of 3.26ly. So to compare it with stars near to Earth, you need to convert your quoted distances to SW parsecs:

Proxima Centauri 0.86 SW parsecs

Alpha Centauri A/B 0.88 SW parsecs

Barnard's Star 1.2 SW parsecs

Wolf 359 1.6 SW parsecs

I wonder what SW's equivalent of a light year is.

Still works for my purposes though. There are a handfull of stars within ~1 parsec from Sol. So having a handfull of stars ~1 parsec from Tatooine is not unreasonable.

I don't know. Was there any reason why Geonosis would be mentioned beyond Ep2? Obi Wan wasn't hiding out there. Luke didn't live there. There's no particular reason for it to be mentioned in Ep4-6, no more than we need to know about the other moons of Yavin in Ep4 (for example).

Yes. It was the first major battleground of the Clone wars and right next to the starsytem that is featured in four of the current five movies (probably will be shown in Ep III too). I find it odd that not a passing reference would be made to it since it was soooo close.

Luke- "You fought in the Clone Wars?"

Ben Kenobi- "Yes, I was once a Jedi Knight, like your father. In fact, we both fought at Geonosis not far from here. He was a good friend."

Or;

Pilot- "Our hyperdrive is leaking. We can't make it all the way to Coruscant."

Qui Gon- "We'll have to find a place to land and make repairs."

Obi Wan- "Master. Tatooine is with in range. Or Geonosis, they atleast have an industrial base that might help us fix or replace the hyperdrive. Finding one on Tatooine might be difficult."

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-04-13 12:43pm

I think Lucasfilm said that Geonosis won't be in EIII.

I'm not going to address the first Ben-Luke thing, since that seems trivial. But as for not mentioning Geonosis in EI: probably because Tatooine is a spaceport while Geonosis is an industrial factory. It's like comparing an airport to an electronics factory.

Mange · Post by **Mange** » 2004-04-13 12:47pm

Knife wrote:
ClaysGhost wrote: Careful. Geonosis and Tatooine are separated by about 1 SW parsec, which Spanky has found to be 4.95 light years rather than our corresponding unit of 3.26ly. So to compare it with stars near to Earth, you need to convert your quoted distances to SW parsecs:

Proxima Centauri 0.86 SW parsecs

Alpha Centauri A/B 0.88 SW parsecs

Barnard's Star 1.2 SW parsecs

Wolf 359 1.6 SW parsecs

I wonder what SW's equivalent of a light year is.
Still works for my purposes though. There are a handfull of stars within ~1 parsec from Sol. So having a handfull of stars ~1 parsec from Tatooine is not unreasonable.

I don't know. Was there any reason why Geonosis would be mentioned beyond Ep2? Obi Wan wasn't hiding out there. Luke didn't live there. There's no particular reason for it to be mentioned in Ep4-6, no more than we need to know about the other moons of Yavin in Ep4 (for example).
Yes. It was the first major battleground of the Clone wars and right next to the starsytem that is featured in four of the current five movies (probably will be shown in Ep III too). I find it odd that not a passing reference would be made to it since it was soooo close.

Luke- "You fought in the Clone Wars?"

Ben Kenobi- "Yes, I was once a Jedi Knight, like your father. In fact, we both fought at Geonosis not far from here. He was a good friend."

Or;

Pilot- "Our hyperdrive is leaking. We can't make it all the way to Coruscant."

Qui Gon- "We'll have to find a place to land and make repairs."

Obi Wan- "Master. Tatooine is with in range. Or Geonosis, they atleast have an industrial base that might help us fix or replace the hyperdrive. Finding one on Tatooine might be difficult."

We don't know that much about the how the society worked on Geonosis before Episode II. If a few strangers landed on Geonosis (they could have been sympatetic with the Trade Federation), it's quite possible that the Geonosians would have had a bit of fun with them, in let's say... an arena?
However, this is off-topic.

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-04-13 12:49pm

Shit, I didn't factor in leap year when doing those light year calcs (365.25 rather than 365). Give me a sec and I'll edit in the correct values here...

EDIT: Okay, SW light years are actually only 1.0072 times greater than ours:

RL LY: 9,460,730,472,580 km
SW LY: 9,531,961,160,601 km

That should be correct this time, unless God hates me and decided to have me forget about something else...

Knife · Post by **Knife** » 2004-04-13 12:53pm

Spanky The Dolphin wrote:I think Lucasfilm said that Geonosis won't be in EIII.

I'm not going to address the first Ben-Luke thing, since that seems trivial. But as for not mentioning Geonosis in EI: probably because Tatooine is a spaceport while Geonosis is an industrial factory. It's like comparing an airport to an electronics factory.

Oh, I'm not saying it should have been a reacuring theme, but to have two major historical planets right next to each other and yet have little or no mention of them being that way is odd.

Ideally, Lucas should have had Geonosis a couple parsecs away giving it a little cushion. But it IS only a parsec away so mentions of Geonosis should be more or less common to Tatooine.

Besides, my quick example was just an example, but Geonosis should have a spaceport if it is so heavily industrailized and while not a 'Core world' should still have been an option since its right next to Tatooine.

Spanky The Dolphin · Post by **Spanky The Dolphin** » 2004-04-13 12:55pm

It could be that nobody cares about factory planets. Obi-Wan could have also been looking for starports specifically, and Tatooine certainly qualifies in that category above Geonosis.

Besides, I like my "airport/electronics factory" analogy.

Mange · Post by **Mange** » 2004-04-13 12:57pm

Spanky The Dolphin wrote:Shit, I didn't factor in leap year when doing those light year calcs (365.25 rather than 365). Give me a sec and I'll edit in the correct values here...

EDIT: Okay, SW light years are actually only 1.0072 times greater than ours:

RL LY: 9,460,730,472,580 km
SW LY: 9,531,961,160,601 km

That should be correct this time, unless God hates me and decided to have me forget about something else...

No, Spanky, you're doing great! Your calculations are excellent! I also forgot to take leap-years into account in my calculations, but I thought the miniscule difference wouldn't matter, but they did as your calculations show!