I've worked on this for D20 Future, but I figure it could appear in charted space as well. From a remote future or a parallel universe this appears in the Spinward Marches.
Location: Trin’s Veil Subsector Hex 0407 – Spinward Marches
Appearance Date: GM’s discretion (Suggested 1105)
Analysis: On the 3rd Month of the year 1108 (or whenever the GM chooses) a gravitational ripple moved across the Hammerium-Robin Trade Route knocking all starships out of jump space in its path, a massive rescue operation had to be organized by the local Imperial government as many ships were stuck in interstellar space without the necessary jump fuel to get out. Adding to the problem was the fact that the exclusion ripple was still expanding outward at the speed of light. A massive fleet carrier was dispatched to the area and was forced to spend the next 4.3 years trapped in the exclusion bubble until the gravity wave ripple dissipated enough to allow a jump out of the area. Hammermuim itself was cutoff for 3 months from interstellar trade. The cause of this disturbance was the sudden appearance of the Ringworld Star. Apparently disgourged by a giant wormhole or jump drive. Where it came from is a mystery. The star type is an exact duplicate of Earth’s Sun, one hypothesis put forward is that the ringworld traveled back in time from a point in the future. Interestingly a plot of Sol’s future orbit in the galaxy would place the era at least 50,000 years in the future. The presence of humans and other Earth creatures on the ringworld’s surface would seem to support this theory.
Ringworld
Radius: 149,604,905 km (92,960,000 miles)
Width: 1,609,347 km (1,000,000 miles)
Period of rotation: 8.838 days
Rotational speed: 4,431,599 km/hour (2,753,663 miles/hour); 1,231 km/sec (764.9 miles/second)
Angular speed: 40.733 degrees per day
Centrifugal Force: 0.976-g (due to Sun’s gravitational pull opposing centrifugal force)
Angular Size of the Sun: 0.53 degrees
Period of daylight: 12 hours
Period of darkness: 12 hours
Total length of day: 24 hours
Twilight: morning twilight begins at 5:49:24 am and ends at 6:10:36 am every day
Twilight: evening twilight begins at 5:49:24 pm and ends at 6:10:36 pm every day
Shadow Squares
Number of Shadow squares: 10
Radius of Shadow Square ring: 57,904,308 km (35,980,000 miles)
Period of rotation: 76 days
Rotational Speed: 199,303 km/hour (123,841 miles/hour) 27,037 kmph above orbital velocity (16,800 mph above orbital velocity)
Rotational Speed: 55.4 km/sec (34.4 miles/sec) 7.52 kmph above orbital velocity (4.67 mph above orbital velocity)
Angular speed: 4.733 degrees per day (0.642 degrees above rate at orbital velocity)
Relative angular speed of ringworld to shadow squares: 36 degrees per day
Angular Length of each shadow square: 18 degrees.
Angular length of gap between squares: 18 degrees.
Length of each shadow square: 18,191,175 km (11,303,450.4 miles) east-west
Length of each gap between shadow squares: 18,191,175 km (11,303,450.4 miles) east-west
Width of shadow Squares: 1,348,633 km (838,000 miles) north-south
The Sun
Diameter: 1,393,695 km (866,000 miles)
Temperature: exterior (photosphere): 5,968 degrees C or 6,241 degrees K(10,800 degrees F)
Gravity: 273-g
Climate at Sea level: Tropical
Encounter Table A – Near Civilization
D100 Result
01-40 Character Encounter
41-00 Animal Encounter (see Appropriate Terrain)
Encounter Table B – The Frontier
D100 Result
01-20 Character Encounter
21-00 Animal Encounter (see Appropriate Terrain)
Encounter Table C – The Wilds
D100 Result
01-10 Character Encounter
11-00 Animal Encounter (see Appropriate Terrain)
Character Encounters
01-05 Aarakocra
06-10 Yazirian
11-15 Weren
16-20 Vrusk
21-25 T’sa
26-30 Sesheyan
31-35 Dralasite
36-40 Robot
41-45 Lizardfolk
46-50 Hill Giant
51-55 Ogre
56-60 Hobgoblin
61-65 Centaur
66-70 Gnome
71-75 Halfling
76-80 Dwarf
81-85 Human
86-90 Orc
91-95 Aleerin
96-00 Elf
Aquatic
Animal Encounters
D100 Result Creature (number appearing)
01-08 Helicoprion (1d12) see above and Dragon Issue 318
09-12 Liopleurodon (1d2) see above and Dragon Issue 318
13-18 Elasmosaurus (1d2) D&D Monster Manual
19-25 Cryptoclidus (1d4, on 1: 1, else: 2d20) D&D Monster Manual II
26-29 Giant Octopus (1)
30-37 Porpoise (1d2) (1d20)Monster Manual
38-45 Medium-size Shark (2d6-1) Monster Manual
46-51 Large Shark (2d6-1) Monster Manual
52-55 Huge Shark (2d6-1) Monster Manual
56-59 Giant Squid (1) Monster Manual
60-67 Baleen Whale (1) Monster Manual
68-75 Cachalot Whale (2d6-1) Monster Manual
76-83 Orca Whale (2d6-1) Monster Manual
84-00 Special-Aerial
Desert
Animal Encounters
D100 Result Creature (number appearing)
01-08 Baboon (1d4- on 1: 1d4, on 2-4: 2d20) Monster Manual
09-16 Camel (1) Monster Manual
17-24 Donkey (1) Monster Manual
25-32 Giant Lizard (1) Monster Manual
33-00 Special
Forest
Animal Encounters
D100 Result Creature (number appearing)
01-06 Compsognathus (1d12) see below and Dragon Issue 318
07-10 Tyrannosaurus Rex (1d2) d20 Menace Manual
11-14 Triceratops (1d8) D&D Monster Manual
15-18 Deinoychus (1d6) D&D Monster Manual
19-22 Megaraptor (1d6) D&D Monster Manual
23-25 Allosaurus (1d2) D&D Monster Manual II
26-29 Ankylosaurus (1d2 or 2d20) D&D Monster Manual II
30-35 Black Bear (1d2)
36-43 Boar (1)
44-51 Eagle (1d2)
52-59 Leopard (1d2)
60-65 Ape (1d6)
66-71 Brown Bear (1d2)
72-77 Elephant (1d30)
78-83 Giant Lizard (1)
84-92 Monkey (10d4)
93-100 Wolf (1d10+6)
Hill
Animal Encounters
D100 Result Creature (number appearing)
01-08 Pachycephalosaurus (1d12) Dragon Issue 318
09-16 Weasel (1) Monster Manual
17-24 Quetzalcoatlus (1d6) Monster Manual II
25-32 Allosaurus (1d2) Monster Manual II
33-40 Ankylosaurus (1d2; on 1:1d20, on 2:2d20) Monster Manual II
41-48 Seismosaurus (1d20) Monster Manual II
49-50 Spinosaurus (1d2) Monster Manual II
51-00 Associated Terrain i.e Forest/Hills, Plains/Hills, Desert/Hills
Marsh
Animal Encounters
D100 Result Creature (number appearing)
01-08 Dimetrodon (1d8) Dragon Issue 318
09-16 Parasaurolophus (1d12) Dragon Issue 318
17-24 Crocodile (1d12) Monster Manual
25-28 Giant Crocodile (1d12) Monster Manual
29-30 Tiny Viper Snake (1) Monster Manual
31-32 Small Viper Snake (1) Monster Manual
33-34 Medium Viper Snake (1) Monster Manual
35-36 Large Viper Snake (1) Monster Manual
37-38 Huge Viper Snake (1) Monster Manual
39-46 Toad (10d10) Monster Manual
47-54 Allosaurus (1d2) Monster Manual II
55-62 Ankylosaurus (1d2 x 1d20) Monster Manual II
63-70 Seismosaurus (1d20) Monster Manual II
71-72 Spinosaurus (1d2) Monster Manual II
73-86 Associated Terrain i.e. Forest/Marsh, Plains/Marsh, Desert/Marsh
87-00 Aquatic
Mountains
Animal Encounters
D100 Result Creature (number appearing)
01-08 Pteranodon (1d10) Dragon Issue 318
09-16 Quetzalcoatlus (1d6) Monster Manual II
17-24 Eagle (1d2) Monster Manual
25-32 Giant Eagle (1d12)
33-00 Special Aerial
Plains
Animal Encounters
D100 Result Creature (number appearing)
01-04 Diplodocus (1d3 x 1d6) Dragon Issue 318
05-08 Giganotosaurus (1d6) Dragon Issue 318
09-12 Stegosaurus (1d10) Dragon Issue 318
13-16 Triceratops (1d8) Monster Manual
17-20 Tyrannosaurus (1d2) Monster Manual
21-24 Allosaurus (1d2) Monster Manual II
25-28 Ankylosaurus (1d2 x 1d20) Monster Manual II
29-32 Seismosaurus (1d20) Monster Manual II
33-34 Spinosaurus (1d2) Monster Manual II
35-42 Baboon (1d10 x 1d4) Monster Manual
43-50 Bison (1d6 x 1d6) Monster Manual
51-58 Cheetah (1d6) Monster Manual
59-66 Dog (1d12) Monster Manual
67-74 Elephant (1d6 x 1d6) Monster Manual
75-82 Horse (1d6 x 1d6) Monster Manual
83-90 Lion (1d10) Monster Manual
91-98 Rhinoceros (1d12) Monster Manual
99-00 Special Aerial
Special
Animal Encounters
D100 Result Creature (number appearing)
01-08 Cat (1) Monster Manual
09-16 Dog (1d8 Monster Manual
17-24 Riding Dog (1d8) Monster Manual
25-32 Heavy Horse (2d10-1 Monster Manual
33-40 Light Horse (2d10-1 Monster Manual
41-48 Giant Lizard (1d4 Monster Manual
49-56 Pony (2d10-1 Monster Manual
57-64 Rat (10d10 Monster Manual
65-66 Tiny Viper Snake (1) Monster Manual
67-68 Small Viper Snake (1) Monster Manual
69-70 Medium-size Viper Snake (1) Monster Manual
71 Large Viper Snake (1) Monster Manual
72 Huge Viper Snake (1) Monster Manual
73-80 Toad (10d10) Monster Manual
81-00 Special Aerial
Special Aerial
Animal Encounters
D100 Result Creature (number appearing)
01-25 Giant Eagle (1d12) Monster Manual
26-50 Giant Owl (1d6) Monster Manual
51-75 Quetzalcoatlus (1d6) Monster Manual II
75-00 Pteranodon (1d10) Monster Manual II
Location: Trin’s Veil Subsector Hex 0407 – Spinward Marches
Appearance Date: GM’s discretion (Suggested 1105)
Analysis: On the 3rd Month of the year 1108 (or whenever the GM chooses) a gravitational ripple moved across the Hammerium-Robin Trade Route knocking all starships out of jump space in its path, a massive rescue operation had to be organized by the local Imperial government as many ships were stuck in interstellar space without the necessary jump fuel to get out. Adding to the problem was the fact that the exclusion ripple was still expanding outward at the speed of light. A massive fleet carrier was dispatched to the area and was forced to spend the next 4.3 years trapped in the exclusion bubble until the gravity wave ripple dissipated enough to allow a jump out of the area. Hammermuim itself was cutoff for 3 months from interstellar trade. The cause of this disturbance was the sudden appearance of the Ringworld Star. Apparently disgourged by a giant wormhole or jump drive. Where it came from is a mystery. The star type is an exact duplicate of Earth’s Sun, one hypothesis put forward is that the ringworld traveled back in time from a point in the future. Interestingly a plot of Sol’s future orbit in the galaxy would place the era at least 50,000 years in the future. The presence of humans and other Earth creatures on the ringworld’s surface would seem to support this theory.
Ringworld
Radius: 149,604,905 km (92,960,000 miles)
Width: 1,609,347 km (1,000,000 miles)
Period of rotation: 8.838 days
Rotational speed: 4,431,599 km/hour (2,753,663 miles/hour); 1,231 km/sec (764.9 miles/second)
Angular speed: 40.733 degrees per day
Centrifugal Force: 0.976-g (due to Sun’s gravitational pull opposing centrifugal force)
Angular Size of the Sun: 0.53 degrees
Period of daylight: 12 hours
Period of darkness: 12 hours
Total length of day: 24 hours
Twilight: morning twilight begins at 5:49:24 am and ends at 6:10:36 am every day
Twilight: evening twilight begins at 5:49:24 pm and ends at 6:10:36 pm every day
Shadow Squares
Number of Shadow squares: 10
Radius of Shadow Square ring: 57,904,308 km (35,980,000 miles)
Period of rotation: 76 days
Rotational Speed: 199,303 km/hour (123,841 miles/hour) 27,037 kmph above orbital velocity (16,800 mph above orbital velocity)
Rotational Speed: 55.4 km/sec (34.4 miles/sec) 7.52 kmph above orbital velocity (4.67 mph above orbital velocity)
Angular speed: 4.733 degrees per day (0.642 degrees above rate at orbital velocity)
Relative angular speed of ringworld to shadow squares: 36 degrees per day
Angular Length of each shadow square: 18 degrees.
Angular length of gap between squares: 18 degrees.
Length of each shadow square: 18,191,175 km (11,303,450.4 miles) east-west
Length of each gap between shadow squares: 18,191,175 km (11,303,450.4 miles) east-west
Width of shadow Squares: 1,348,633 km (838,000 miles) north-south
The Sun
Diameter: 1,393,695 km (866,000 miles)
Temperature: exterior (photosphere): 5,968 degrees C or 6,241 degrees K(10,800 degrees F)
Gravity: 273-g
Climate at Sea level: Tropical
Encounter Table A – Near Civilization
D100 Result
01-40 Character Encounter
41-00 Animal Encounter (see Appropriate Terrain)
Encounter Table B – The Frontier
D100 Result
01-20 Character Encounter
21-00 Animal Encounter (see Appropriate Terrain)
Encounter Table C – The Wilds
D100 Result
01-10 Character Encounter
11-00 Animal Encounter (see Appropriate Terrain)
Character Encounters
01-05 Aarakocra
06-10 Yazirian
11-15 Weren
16-20 Vrusk
21-25 T’sa
26-30 Sesheyan
31-35 Dralasite
36-40 Robot
41-45 Lizardfolk
46-50 Hill Giant
51-55 Ogre
56-60 Hobgoblin
61-65 Centaur
66-70 Gnome
71-75 Halfling
76-80 Dwarf
81-85 Human
86-90 Orc
91-95 Aleerin
96-00 Elf
Aquatic
Animal Encounters
D100 Result Creature (number appearing)
01-08 Helicoprion (1d12) see above and Dragon Issue 318
09-12 Liopleurodon (1d2) see above and Dragon Issue 318
13-18 Elasmosaurus (1d2) D&D Monster Manual
19-25 Cryptoclidus (1d4, on 1: 1, else: 2d20) D&D Monster Manual II
26-29 Giant Octopus (1)
30-37 Porpoise (1d2) (1d20)Monster Manual
38-45 Medium-size Shark (2d6-1) Monster Manual
46-51 Large Shark (2d6-1) Monster Manual
52-55 Huge Shark (2d6-1) Monster Manual
56-59 Giant Squid (1) Monster Manual
60-67 Baleen Whale (1) Monster Manual
68-75 Cachalot Whale (2d6-1) Monster Manual
76-83 Orca Whale (2d6-1) Monster Manual
84-00 Special-Aerial
Desert
Animal Encounters
D100 Result Creature (number appearing)
01-08 Baboon (1d4- on 1: 1d4, on 2-4: 2d20) Monster Manual
09-16 Camel (1) Monster Manual
17-24 Donkey (1) Monster Manual
25-32 Giant Lizard (1) Monster Manual
33-00 Special
Forest
Animal Encounters
D100 Result Creature (number appearing)
01-06 Compsognathus (1d12) see below and Dragon Issue 318
07-10 Tyrannosaurus Rex (1d2) d20 Menace Manual
11-14 Triceratops (1d8) D&D Monster Manual
15-18 Deinoychus (1d6) D&D Monster Manual
19-22 Megaraptor (1d6) D&D Monster Manual
23-25 Allosaurus (1d2) D&D Monster Manual II
26-29 Ankylosaurus (1d2 or 2d20) D&D Monster Manual II
30-35 Black Bear (1d2)
36-43 Boar (1)
44-51 Eagle (1d2)
52-59 Leopard (1d2)
60-65 Ape (1d6)
66-71 Brown Bear (1d2)
72-77 Elephant (1d30)
78-83 Giant Lizard (1)
84-92 Monkey (10d4)
93-100 Wolf (1d10+6)
Hill
Animal Encounters
D100 Result Creature (number appearing)
01-08 Pachycephalosaurus (1d12) Dragon Issue 318
09-16 Weasel (1) Monster Manual
17-24 Quetzalcoatlus (1d6) Monster Manual II
25-32 Allosaurus (1d2) Monster Manual II
33-40 Ankylosaurus (1d2; on 1:1d20, on 2:2d20) Monster Manual II
41-48 Seismosaurus (1d20) Monster Manual II
49-50 Spinosaurus (1d2) Monster Manual II
51-00 Associated Terrain i.e Forest/Hills, Plains/Hills, Desert/Hills
Marsh
Animal Encounters
D100 Result Creature (number appearing)
01-08 Dimetrodon (1d8) Dragon Issue 318
09-16 Parasaurolophus (1d12) Dragon Issue 318
17-24 Crocodile (1d12) Monster Manual
25-28 Giant Crocodile (1d12) Monster Manual
29-30 Tiny Viper Snake (1) Monster Manual
31-32 Small Viper Snake (1) Monster Manual
33-34 Medium Viper Snake (1) Monster Manual
35-36 Large Viper Snake (1) Monster Manual
37-38 Huge Viper Snake (1) Monster Manual
39-46 Toad (10d10) Monster Manual
47-54 Allosaurus (1d2) Monster Manual II
55-62 Ankylosaurus (1d2 x 1d20) Monster Manual II
63-70 Seismosaurus (1d20) Monster Manual II
71-72 Spinosaurus (1d2) Monster Manual II
73-86 Associated Terrain i.e. Forest/Marsh, Plains/Marsh, Desert/Marsh
87-00 Aquatic
Mountains
Animal Encounters
D100 Result Creature (number appearing)
01-08 Pteranodon (1d10) Dragon Issue 318
09-16 Quetzalcoatlus (1d6) Monster Manual II
17-24 Eagle (1d2) Monster Manual
25-32 Giant Eagle (1d12)
33-00 Special Aerial
Plains
Animal Encounters
D100 Result Creature (number appearing)
01-04 Diplodocus (1d3 x 1d6) Dragon Issue 318
05-08 Giganotosaurus (1d6) Dragon Issue 318
09-12 Stegosaurus (1d10) Dragon Issue 318
13-16 Triceratops (1d8) Monster Manual
17-20 Tyrannosaurus (1d2) Monster Manual
21-24 Allosaurus (1d2) Monster Manual II
25-28 Ankylosaurus (1d2 x 1d20) Monster Manual II
29-32 Seismosaurus (1d20) Monster Manual II
33-34 Spinosaurus (1d2) Monster Manual II
35-42 Baboon (1d10 x 1d4) Monster Manual
43-50 Bison (1d6 x 1d6) Monster Manual
51-58 Cheetah (1d6) Monster Manual
59-66 Dog (1d12) Monster Manual
67-74 Elephant (1d6 x 1d6) Monster Manual
75-82 Horse (1d6 x 1d6) Monster Manual
83-90 Lion (1d10) Monster Manual
91-98 Rhinoceros (1d12) Monster Manual
99-00 Special Aerial
Special
Animal Encounters
D100 Result Creature (number appearing)
01-08 Cat (1) Monster Manual
09-16 Dog (1d8 Monster Manual
17-24 Riding Dog (1d8) Monster Manual
25-32 Heavy Horse (2d10-1 Monster Manual
33-40 Light Horse (2d10-1 Monster Manual
41-48 Giant Lizard (1d4 Monster Manual
49-56 Pony (2d10-1 Monster Manual
57-64 Rat (10d10 Monster Manual
65-66 Tiny Viper Snake (1) Monster Manual
67-68 Small Viper Snake (1) Monster Manual
69-70 Medium-size Viper Snake (1) Monster Manual
71 Large Viper Snake (1) Monster Manual
72 Huge Viper Snake (1) Monster Manual
73-80 Toad (10d10) Monster Manual
81-00 Special Aerial
Special Aerial
Animal Encounters
D100 Result Creature (number appearing)
01-25 Giant Eagle (1d12) Monster Manual
26-50 Giant Owl (1d6) Monster Manual
51-75 Quetzalcoatlus (1d6) Monster Manual II
75-00 Pteranodon (1d10) Monster Manual II