Real Stars in Charted Space

[Garnfellow]

Although considerable distortion occurs when 3-D stellar positions are projected onto a 2-D jump map, several people over the years have tried to place real stars in Charted Space.

Several stars, mostly in the Solomani Rim, have canonical positions; most of these were obliquely established in Classic Traveller Alien Module 6 - Solomani. (See also "The Known Star List for the Solomani Rim" from Traveller Chronicle 10.) Some maps of Charted Space have positions of very bright stars, though these are very hit or miss: Antares is in vaguely the right position, but Deneb and Canopus are far too close to Terra.

I decided to give it a try myself, starting with list of the 300 Brightest Stars from the "An Atlas of the Universe" website.

This list gives distance from Terra and position in galactic longitude. Assuming 0 degrees galactic longitude corresponds to coreward, and 90 degrees corresponds to spinward, using a little trigonometry we can then calculate the approximate position within Charted Space of these stars. I was hoping to get some eyes on my Google Sheets to make sure my methodology works:

The Brightest Real-World Stars in Charted Space

The Google Sheets workbook contains a Notes sheet that goes into more detail, but basically I translated the galactic longitude and distance into polar coordinates with Terra (Solomani Rim 1827) at position (0,0). I then converted those coordinates into hex offsets, and then determined where the resulting position fell within Charted Space to get a sector and hex number.

There are several places where I could have screwed up, so I would welcome any questions, thoughts, or corrections.

 

[whulorigan]

Although considerable distortion occurs when 3-D stellar positions are projected onto a 2-D jump map, several people over the years have tried to place real stars in Charted Space.

Several stars, mostly in the Solomani Rim, have canonical positions. Some maps of Charted Space have positions of very bright stars, though these are very hit or miss: Antares is in vaguely the right position, but Deneb and Canopus are far too close to Terra.

I decided to give it a try myself, starting with a list of the 300 Brightest Stars.

This list gives distance from Terra and position in galactic longitude. Assuming 0 degrees galactic longitude corresponds to coreward, and 90 degrees corresponds to spinward, using a little trigonometry we can then calculate the approximate position within Charted Space of these stars. I was hoping to get some eyes on my Google Sheets to make sure my methodology works:

The Brightest Real-World Stars in Charted Space

There's a Notes sheet that goes into more detail, but basically I translated the galactic longitude and distance into polar coordinates with Terra (Solomani Rim 1827) at position (0,0). I then converted those coordinates into hex offsets, and then determined where the resulting position fell within Charted Space to get a sector and hex number.

There are several places where I could have screwed up, so I would welcome any questions, thoughts, or corrections.

As a quick note: One thing that I have discovered when I have compared real-world star positions to the Traveller Map of Charted Space is that the axes of the Charted Space Map appear to be tilted almost exactly 45^o counter-clockwise from the correct position (i.e. "true" Coreward actually lies parallel to the Lesser Rift). If you make that adjustment, about 70% of the named stars will fall roughly along their correct bearing. ^*

^* - there are some exceptions (such as Antares which you mentioned) that lie in roughly the correct position relative to the Charted Space Map without the need to rotate the coordinate axes.
​

For example: Prometheus canonically orbits Alpha Centauri. The real Alpha Centauri lies at bearing 315^o (roughly in the plane of the map). But on the Charted Space Map, it lies at a bearing of 270^o. It is tilted exactly 45^o clockwise from its true position. If you pick a number of other near-Earth named stars (e.g. Sirius, Barnard's Star, Procyon, etc) and check their Galactic Longitude, you will find that about 70% of them are tilted close to the same amount (but as mentioned above - not all). For example, the real Deneb (which actually lies at least twice the distance as shown on the Charted Space Map) in actuality lies at a bearing of almost 90^o (due Spinward). But Charted Space shows its bearing as Corespinward.

So when I am assigning the position of a Real-Universe star to a Traveller Map hex, I use the convention that as long as it is within a 45^o bearing-arc between the "true" coordinate axes and the Charted Space Map coordinate axes, I am content.

 

[Garnfellow]

For example, the real Deneb (which actually lies at least twice the distance as shown on the Charted Space Map) in actuality lies at a bearing of almost 90^o (due Spinward). But Charted Space shows its bearing as Corespinward.

Two of the most wackadoodle stars for position and distance -- Deneb and Alpha Crucis -- were partially retconned in Mongoose Traveller materials. The Solomani book claims Alpha Crucis was named after a religious organization, not the star. And Rob, who "wrote the book on Deneb" claims the sector and the real star simply share a common name but are otherwise unrelated.

 

[Garnfellow]

As a quick note: One thing that I have discovered when I have compared real-world star positions to the Traveller Map of Charted Space is that the axes of the Charted Space Map appear to be tilted almost exactly 45^o counter-clockwise from the correct position (i.e. "true" Coreward actually lies parallel to the Lesser Rift). If you make that adjustment, about 70% of the named stars will fall roughly along their correct bearing. ^*

^* - there are some exceptions (such as Antares which you mentioned) that lie in roughly the correct position relative to the Charted Space Map without the need to rotate the coordinate axes.​

I was looking at an adjustment of about 8 degrees counter-clockwise myself, just so Aldebaran actually falls into Aldebaran subsector. I haven't yet actually made a tweak like that, only because about a third of the canonical Rim positions work as is.

But if my current spreadsheet seems to check out, I would definitely look at tweaking it, understanding that it's probably a fool's errand -- tweak it one way, some canonical stars snap into place but others fall out; tweak it another, more stars hit while others miss.​

 

[whulorigan]

Two of the most wackadoodle stars for position and distance -- Deneb and Alpha Crucis -- were partially retconned in Mongoose Traveller materials. The Solomani book claims Alpha Crucis was named after a religious organization, not the star. And Rob, who "wrote the book on Deneb" claims the sector and the real star simply share a common name but are otherwise unrelated.

Alpha Crucis (the star) should be 3 sectors Trailing of Sol, not 1 (although Gamma Crucis does lie in the Alpha Crucis Sector region). Some have also unofficially renamed the Sector Alpha Leonis, after the bright star Regulus (which used to be canonically located in the Regulus Subsector, but the star that used to be named Regulus on TravellerMap has now been renamed "Basilicus" and its stellar type has been changed).

Personally I do not like the MgT Alpha Crucis explanation (the religious organization by itself is fine - just not as the origin of the name of the Sector).

As far as Deneb goes, the name actually comes from the Arabic "Dhanab" meaning "tail" (as in the tail-star of Cygnus the Swan). There are several stars whose historical (Arabic) names include some version of the word "Dhanab" (and are the tail-stars of their respective constellations as well). Unfortunately I have not yet found one at the right bearing and distance with the right spectral type to be the "Deneb/Dheneb/Dhanab" located on the Charted Space Map.

 

[whulorigan]

I was looking at an adjustment of about 8 degrees counter-clockwise myself, just so Aldebaran actually falls into Aldebaran subsector. I haven't yet actually made a tweak like that, only because about a third of the canonical Rim positions work as is.

But if my current spreadsheet seems to check out, I would definitely look at tweaking it, understanding that it's probably a fool's errand -- tweak it one way, some canonical stars snap into place but others fall out; tweak it another, more stars hit while others miss.

You will never make them all fit perfectly at any angle. That is why I use the "45^o sweep of relative bearing" rule. I chalk up discrepancies to the different topology of Jumpspace as compared to Normal space. The hex-grid is a jump-map after all. I just try and get them close to the correct position.

 

[savage]

It would be nice if the 21 closest stars (to Terra / Earth) we're somewhat accurate. Others can be chalked up to naming anomalies. For example, originally it was called New Regina over the centuries the dropped the New and now it's considered Regina.

 

[Theophilus]

Does this also account for 3000 years of relative motion, since the Traveller setting is set in the far future?

 

[mike wightman]

Are you planning to produce a sector map using this data?

 

[ovka]

It's interesting to note that the MT CD Rom from FFE has a hand-drawn annotated map of charted space that shows Deneb beyond Zhodani space in what would be Viajlefliez Sector. It also shows Antares in Ley Sector. It shows the location of a pretty fair number of stars in the region of the Solomani Sphere. I'm not sure how close it is to being accurate, but it's worth looking at as part of this discussion.

Cheers,

Baron Ovka

 

[whulorigan]

MT-CDROM

It's interesting to note that the MT CD Rom from FFE has a hand-drawn annotated map of charted space that shows Deneb beyond Zhodani space in what would be Viajlefliez Sector. It also shows Antares in Ley Sector. It shows the location of a pretty fair number of stars in the region of the Solomani Sphere. I'm not sure how close it is to being accurate, but it's worth looking at as part of this discussion.

Cheers,

Baron Ovka

Ovka, what folder on your MegaTraveller CDROM are you looking in? I cannot find the hand-drawn map you mention above or the Trader's Guild ship recognition chart you noted on the Trader's Guild thread.

I have one of the original MT-CDROMs (from about ~2005); I am wondering whether or not the current edition on FFE is an updated 2nd Edition of the Disc (and whether or not I should repurchase the disc)?

 

[Garnfellow]

Does this also account for 3000 years of relative motion, since the Traveller setting is set in the far future?

Right now I'm more concerned about accounting for my 30 year old recollection of trigonometry.

 

[Garnfellow]

Are you planning to produce a sector map using this data?

I'm using it to inform my regenerated data of the rimward Solomani Confederation sectors.

 

[Garnfellow]

It's interesting to note that the MT CD Rom from FFE has a hand-drawn annotated map of charted space that shows Deneb beyond Zhodani space in what would be Viajlefliez Sector. It also shows Antares in Ley Sector. It shows the location of a pretty fair number of stars in the region of the Solomani Sphere. I'm not sure how close it is to being accurate, but it's worth looking at as part of this discussion.

I did not see that. Now I need to find a CD rom drive.

 

[ovka]

Ovka, what folder on your MegaTraveller CDROM are you looking in? I cannot find the hand-drawn map you mention above or the Trader's Guild ship recognition chart you noted on the Trader's Guild thread.

I have one of the original MT-CDROMs (from about ~2005); I am wondering whether or not the current edition on FFE is an updated 2nd Edition of the Disc (and whether or not I should repurchase the disc)?

The Traders' Guild Guide to Starships is in the Art Gallery Symbols/Ships directory on my CD ROM. The Traders' Guild Logo is in the Art Gallery Symbols/Symbols directory. Hand-drawn, annotated map of charted space is in the Images directory.

At least on *my* version of the CD ROM. It looks like it is from 2012.

Cheers,

Baron Ovka

 

[whulorigan]

The Traders' Guild Guide to Starships is in the Art Gallery Symbols/Ships directory on my CD ROM. The Traders' Guild Logo is in the Art Gallery Symbols/Symbols directory. Hand-drawn, annotated map of charted space is in the Images directory.

At least on *my* version of the CD ROM. It looks like it is from 2012.

Cheers,

Baron Ovka

Mine does not even have an "Art Gallery Symbols/Ships directory", and there is no map in my Images directory.

Looks like I need to get an updated CDROM . . .

 

[maksimsmelchak]

Although considerable distortion occurs when 3-D stellar positions are projected onto a 2-D jump map, several people over the years have tried to place real stars in Charted Space.

Several stars, mostly in the Solomani Rim, have canonical positions; most of these were obliquely established in Classic Traveller Alien Module 6 - Solomani. (See also "The Known Star List for the Solomani Rim" from Traveller Chronicle 10.) Some maps of Charted Space have positions of very bright stars, though these are very hit or miss: Antares is in vaguely the right position, but Deneb and Canopus are far too close to Terra.

I decided to give it a try myself, starting with list of the 300 Brightest Stars from the "An Atlas of the Universe" website.

This list gives distance from Terra and position in galactic longitude. Assuming 0 degrees galactic longitude corresponds to coreward, and 90 degrees corresponds to spinward, using a little trigonometry we can then calculate the approximate position within Charted Space of these stars. I was hoping to get some eyes on my Google Sheets to make sure my methodology works:

The Brightest Real-World Stars in Charted Space

The Google Sheets workbook contains a Notes sheet that goes into more detail, but basically I translated the galactic longitude and distance into polar coordinates with Terra (Solomani Rim 1827) at position (0,0). I then converted those coordinates into hex offsets, and then determined where the resulting position fell within Charted Space to get a sector and hex number.

There are several places where I could have screwed up, so I would welcome any questions, thoughts, or corrections.

Really, really neat work. I've always had a hankering to match up Traveller Space with Real Space, but never did anything about it.

Shalom,
Maksim-Smelchak.

 

[Garnfellow]

It's interesting to note that the MT CD Rom from FFE has a hand-drawn annotated map of charted space that shows Deneb beyond Zhodani space in what would be Viajlefliez Sector. It also shows Antares in Ley Sector. It shows the location of a pretty fair number of stars in the region of the Solomani Sphere. I'm not sure how close it is to being accurate, but it's worth looking at as part of this discussion.

So I had a chance to take a look at this map, and it's very cool and deeply weird, and probably raises many more questions than it answers.

The map has a penciled in layer of sectors and borders that very much looks like our familiar Charted Space. On top of this layer are blue ink annotations of stars.

So the map shows spinward as 0 hours right ascension, and rimward as 6 hours right ascension, trailing at 12 hours, and coreward at 18 hours.

The coreward-rimward scale of 40 parsecs per sector is right, but the trailing-spinward scale appears to be wrong. Although partially cut off, it appears to say sectors are 32 parsecs wide. Although a sector is 32 hexes wide, in distance a sector is only about 28 parsecs wide because of the way the hexes "nest" in each other.

But the really weird thing is the location of Terra, which appears to be in subsector D, near the edge of Magyar, nowhere near Sol Subsector (K).

Now the map is copyright 1980, and Supplement 10: The Solomani Rim is 1982, so one wonders what happened.

Very interesting stuff, indeed.

 

[savage]

Now the map is copyright 1980, and Supplement 10: The Solomani Rim is 1982, so one wonders what happened.
Supplement 10: The Solomani Rim is 1982, so one wonders what happened.
Very interesting stuff, indeed.

Simple answer. GDW art department.

 

[inexorabletash]

The coreward-rimward scale of 40 parsecs per sector is right, but the trailing-spinward scale appears to be wrong. Although partially cut off, it appears to say sectors are 32 parsecs wide. Although a sector is 32 hexes wide, in distance a sector is only about 28 parsecs wide because of the way the hexes "nest" in each other.

The source of much cartographic confusion in Traveller.