Calculations of Orbital Periods for Traveller Orbit distances used are those for Traveller 5 in the Ranges section (Orbits) as of November 2011. In AU, they are: 0.2, 0.4, 0.7, 1.0, 1.6, 2.8, 5.2, 10, 20, 40, 77, 154, 308, 615, 1230, 2458, 4916, 9830, 19500, 39500, 78700 Masses of different stellar types are approximate masses drawn from real world data. A representative sample of stellar masses is given, values between those given can be interpolated. I find this data to be useful in getting a sense of the time periods of natural cycles on planets, and to get a sense of the dynamics of a system based on the movements of the planets present. For example, if an outer planet is the mainworld for a system, and another is an important source of resources, how likely are they to be near each other in their orbits, and if they're near or far, how long until that situation changes? It's also a basis for seeing how the local calendar is likely to interact with the Imperial or standard calendar. Enjoy, Mark Graybill The Tables: Planetary Orbital Periods for star, class M8, of 0.1 solar masses: Orbit 0 period is 103.3 days. Orbit 1 period is 292.2 days. Orbit 2 period is 676.4 days or 1.9 years. Orbit 3 period is 1155.0 days or 3.2 years. Orbit 4 period is 2337.5 days or 6.4 years. Orbit 5 period is 5411.5 days or 14.8 years. Orbit 6 period is 13695.7 days or 37.5 years. Orbit 7 period is 36524.2 days or 100.0 years. Orbit 8 period is 103306.0 days or 282.8 years. Orbit 9 period is 292193.6 days or 800.0 years. Orbit 10 period is 780399.2 days or 2136.7 years. Orbit 11 period is 2207302.2 days or 6043.4 years. Orbit 12 period is 6243193.5 days or 17093.3 years. Orbit 13 period is 1.7615434E7 days or 48229.5 years. Orbit 14 period is 4.9823976E7 days or 136413.6 years. Orbit 15 period is 1.40751664E8 days or 385365.5 years. Orbit 16 period is 3.98105824E8 days or 1089978.2 years. Orbit 17 period is 1.12566963E9 days or 3081983.0 years. Orbit 18 period is 3.14508672E9 days or 8610966.0 years. Orbit 19 period is 9.067266E9 days or 2.4825364E7 years. Orbit 20 period is 2.55001539E10 days or 6.9817144E7 years. Planetary Orbital Periods for star, class M5, of 0.21 solar masses: Orbit 0 period is 71.3 days. Orbit 1 period is 201.6 days. Orbit 2 period is 466.8 days. Orbit 3 period is 797.0 days or 2.2 years. Orbit 4 period is 1613.1 days or 4.4 years. Orbit 5 period is 3734.3 days or 10.2 years. Orbit 6 period is 9451.0 days or 25.9 years. Orbit 7 period is 25204.1 days or 69.0 years. Orbit 8 period is 71287.9 days or 195.2 years. Orbit 9 period is 201632.7 days or 552.1 years. Orbit 10 period is 538526.6 days or 1474.4 years. Orbit 11 period is 1523183.2 days or 4170.3 years. Orbit 12 period is 4308213.0 days or 11795.5 years. Orbit 13 period is 1.2155805E7 days or 33281.5 years. Orbit 14 period is 3.4381808E7 days or 94134.3 years. Orbit 15 period is 9.712788E7 days or 265927.5 years. Orbit 16 period is 2.74719136E8 days or 752156.5 years. Orbit 17 period is 7.7678592E8 days or 2126770.5 years. Orbit 18 period is 2.17031603E9 days or 5942131.5 years. Orbit 19 period is 6.2570076E9 days or 1.7131128E7 years. Orbit 20 period is 1.75967785E10 days or 4.8178408E7 years. Planetary Orbital Periods for star, class M0, of 0.47 solar masses: Orbit 0 period is 47.7 days. Orbit 1 period is 134.8 days. Orbit 2 period is 312.0 days. Orbit 3 period is 532.8 days or 1.5 years. Orbit 4 period is 1078.2 days or 3.0 years. Orbit 5 period is 2496.1 days or 6.8 years. Orbit 6 period is 6317.4 days or 17.3 years. Orbit 7 period is 16847.4 days or 46.1 years. Orbit 8 period is 47651.5 days or 130.5 years. Orbit 9 period is 134778.9 days or 369.0 years. Orbit 10 period is 359971.3 days or 985.6 years. Orbit 11 period is 1018152.6 days or 2787.6 years. Orbit 12 period is 2879770.5 days or 7884.6 years. Orbit 13 period is 8125394.5 days or 22246.6 years. Orbit 14 period is 2.2982086E7 days or 62922.9 years. Orbit 15 period is 6.4923904E7 days or 177755.9 years. Orbit 16 period is 1.83632528E8 days or 502769.5 years. Orbit 17 period is 5.19232736E8 days or 1421613.0 years. Orbit 18 period is 1.45072026E9 days or 3971942.5 years. Orbit 19 period is 4.18241792E9 days or 1.1451087E7 years. Orbit 20 period is 1.17623439E10 days or 3.2204246E7 years. Planetary Orbital Periods for star, class K5, of 0.74 solar masses: Orbit 0 period is 38.0 days. Orbit 1 period is 107.4 days. Orbit 2 period is 248.7 days. Orbit 3 period is 424.6 days. Orbit 4 period is 859.3 days or 2.4 years. Orbit 5 period is 1989.3 days or 5.4 years. Orbit 6 period is 5034.7 days or 13.8 years. Orbit 7 period is 13426.6 days or 36.8 years. Orbit 8 period is 37976.1 days or 104.0 years. Orbit 9 period is 107412.5 days or 294.1 years. Orbit 10 period is 286880.4 days or 785.5 years. Orbit 11 period is 811420.4 days or 2221.6 years. Orbit 12 period is 2295043.5 days or 6283.6 years. Orbit 13 period is 6475562.5 days or 17729.5 years. Orbit 14 period is 1.8315656E7 days or 50146.6 years. Orbit 15 period is 5.174134E7 days or 141663.2 years. Orbit 16 period is 1.46346608E8 days or 400684.0 years. Orbit 17 period is 4.13804416E8 days or 1132959.6 years. Orbit 18 period is 1.15615693E9 days or 3165454.5 years. Orbit 19 period is 3.33319322E9 days or 9125986.0 years. Orbit 20 period is 9.3740431E9 days or 2.5665292E7 years. Planetary Orbital Periods for star, class K0, of 0.85 solar masses: Orbit 0 period is 35.4 days. Orbit 1 period is 100.2 days. Orbit 2 period is 232.0 days. Orbit 3 period is 396.2 days. Orbit 4 period is 801.8 days or 2.2 years. Orbit 5 period is 1856.1 days or 5.1 years. Orbit 6 period is 4697.6 days or 12.9 years. Orbit 7 period is 12527.7 days or 34.3 years. Orbit 8 period is 35433.7 days or 97.0 years. Orbit 9 period is 100221.6 days or 274.4 years. Orbit 10 period is 267674.7 days or 732.9 years. Orbit 11 period is 757098.4 days or 2072.9 years. Orbit 12 period is 2141397.5 days or 5863.0 years. Orbit 13 period is 6042044.5 days or 16542.6 years. Orbit 14 period is 1.7089482E7 days or 46789.5 years. Orbit 15 period is 4.827742E7 days or 132179.3 years. Orbit 16 period is 1.36549168E8 days or 373859.4 years. Orbit 17 period is 3.86101536E8 days or 1057111.6 years. Orbit 18 period is 1.07875584E9 days or 2953537.2 years. Orbit 19 period is 3.11004646E9 days or 8515030.0 years. Orbit 20 period is 8.7464806E9 days or 2.3947084E7 years. Planetary Orbital Periods for star, class G5, of 0.93 solar masses: Orbit 0 period is 33.9 days. Orbit 1 period is 95.8 days. Orbit 2 period is 221.8 days. Orbit 3 period is 378.7 days. Orbit 4 period is 766.5 days or 2.1 years. Orbit 5 period is 1774.5 days or 4.9 years. Orbit 6 period is 4491.0 days or 12.3 years. Orbit 7 period is 11976.8 days or 32.8 years. Orbit 8 period is 33875.4 days or 92.7 years. Orbit 9 period is 95814.1 days or 262.3 years. Orbit 10 period is 255903.0 days or 700.6 years. Orbit 11 period is 723802.9 days or 1981.7 years. Orbit 12 period is 2047223.8 days or 5605.1 years. Orbit 13 period is 5776329.0 days or 15815.1 years. Orbit 14 period is 1.6337925E7 days or 44731.8 years. Orbit 15 period is 4.6154288E7 days or 126366.3 years. Orbit 16 period is 1.3054404E8 days or 357417.9 years. Orbit 17 period is 3.69121632E8 days or 1010622.2 years. Orbit 18 period is 1.03131456E9 days or 2823647.2 years. Orbit 19 period is 2.9732736E9 days or 8140557.5 years. Orbit 20 period is 8.3618304E9 days or 2.2893946E7 years. Planetary Orbital Periods for star, class G2, of 1.0 solar masses: Orbit 0 period is 32.7 days. Orbit 1 period is 92.4 days. Orbit 2 period is 213.9 days. Orbit 3 period is 365.2 days. Orbit 4 period is 739.2 days or 2.0 years. Orbit 5 period is 1711.3 days or 4.7 years. Orbit 6 period is 4331.0 days or 11.9 years. Orbit 7 period is 11550.0 days or 31.6 years. Orbit 8 period is 32668.2 days or 89.4 years. Orbit 9 period is 92399.7 days or 253.0 years. Orbit 10 period is 246783.9 days or 675.7 years. Orbit 11 period is 698010.2 days or 1911.1 years. Orbit 12 period is 1974271.1 days or 5405.4 years. Orbit 13 period is 5570489.5 days or 15251.5 years. Orbit 14 period is 1.5755724E7 days or 43137.8 years. Orbit 15 period is 4.4509584E7 days or 121863.3 years. Orbit 16 period is 1.25892112E8 days or 344681.4 years. Orbit 17 period is 3.55968032E8 days or 974608.8 years. Orbit 18 period is 9.9456371E8 days or 2723026.5 years. Orbit 19 period is 2.86732134E9 days or 7850469.5 years. Orbit 20 period is 8.0638572E9 days or 2.2078122E7 years. Planetary Orbital Periods for star, class G0, of 1.1 solar masses: Orbit 0 period is 31.1 days. Orbit 1 period is 88.1 days. Orbit 2 period is 204.0 days. Orbit 3 period is 348.2 days. Orbit 4 period is 704.8 days or 1.9 years. Orbit 5 period is 1631.6 days or 4.5 years. Orbit 6 period is 4129.4 days or 11.3 years. Orbit 7 period is 11012.5 days or 30.2 years. Orbit 8 period is 31147.9 days or 85.3 years. Orbit 9 period is 88099.7 days or 241.2 years. Orbit 10 period is 235299.2 days or 644.2 years. Orbit 11 period is 665526.7 days or 1822.2 years. Orbit 12 period is 1882393.6 days or 5153.8 years. Orbit 13 period is 5311253.5 days or 14541.7 years. Orbit 14 period is 1.5022493E7 days or 41130.2 years. Orbit 15 period is 4.2438224E7 days or 116192.1 years. Orbit 16 period is 1.20033416E8 days or 328640.8 years. Orbit 17 period is 3.39402208E8 days or 929253.0 years. Orbit 18 period is 9.482793E8 days or 2596304.0 years. Orbit 19 period is 2.73388339E9 days or 7485129.0 years. Orbit 20 period is 7.6885857E9 days or 2.105066E7 years. Planetary Orbital Periods for star, class F5, of 1.29 solar masses: Orbit 0 period is 28.8 days. Orbit 1 period is 81.4 days. Orbit 2 period is 188.3 days. Orbit 3 period is 321.6 days. Orbit 4 period is 650.8 days or 1.8 years. Orbit 5 period is 1506.7 days or 4.1 years. Orbit 6 period is 3813.2 days or 10.4 years. Orbit 7 period is 10169.2 days or 27.8 years. Orbit 8 period is 28762.8 days or 78.7 years. Orbit 9 period is 81353.4 days or 222.7 years. Orbit 10 period is 217281.1 days or 594.9 years. Orbit 11 period is 614563.8 days or 1682.6 years. Orbit 12 period is 1738248.8 days or 4759.2 years. Orbit 13 period is 4904543.0 days or 13428.2 years. Orbit 14 period is 1.3872142E7 days or 37980.7 years. Orbit 15 period is 3.9188504E7 days or 107294.6 years. Orbit 16 period is 1.10841824E8 days or 303475.0 years. Orbit 17 period is 3.13412384E8 days or 858095.2 years. Orbit 18 period is 8.7566458E8 days or 2397491.5 years. Orbit 19 period is 2.52453555E9 days or 6911953.0 years. Orbit 20 period is 7.0998303E9 days or 1.94387E7 years. Planetary Orbital Periods for star, class F0, of 1.7 solar masses: Orbit 0 period is 25.1 days. Orbit 1 period is 70.9 days. Orbit 2 period is 164.1 days. Orbit 3 period is 280.1 days. Orbit 4 period is 566.9 days or 1.6 years. Orbit 5 period is 1312.5 days or 3.6 years. Orbit 6 period is 3321.7 days or 9.1 years. Orbit 7 period is 8858.4 days or 24.3 years. Orbit 8 period is 25055.4 days or 68.6 years. Orbit 9 period is 70867.4 days or 194.0 years. Orbit 10 period is 189274.6 days or 518.2 years. Orbit 11 period is 535349.4 days or 1465.7 years. Orbit 12 period is 1514196.8 days or 4145.7 years. Orbit 13 period is 4272370.5 days or 11697.4 years. Orbit 14 period is 1.2084089E7 days or 33085.2 years. Orbit 15 period is 3.4137292E7 days or 93464.9 years. Orbit 16 period is 9.655484E7 days or 264358.5 years. Orbit 17 period is 2.73015008E8 days or 747490.7 years. Orbit 18 period is 7.6279552E8 days or 2088466.0 years. Orbit 19 period is 2.19913498E9 days or 6021035.0 years. Orbit 20 period is 6.1846958E9 days or 1.6933146E7 years. Planetary Orbital Periods for star, class A5, of 2.1 solar masses: Orbit 0 period is 22.5 days. Orbit 1 period is 63.8 days. Orbit 2 period is 147.6 days. Orbit 3 period is 252.0 days. Orbit 4 period is 510.1 days or 1.4 years. Orbit 5 period is 1180.9 days or 3.2 years. Orbit 6 period is 2988.7 days or 8.2 years. Orbit 7 period is 7970.2 days or 21.8 years. Orbit 8 period is 22543.2 days or 61.7 years. Orbit 9 period is 63761.9 days or 174.6 years. Orbit 10 period is 170297.1 days or 466.3 years. Orbit 11 period is 481672.8 days or 1318.8 years. Orbit 12 period is 1362376.5 days or 3730.1 years. Orbit 13 period is 3844003.2 days or 10524.5 years. Orbit 14 period is 1.0872483E7 days or 29767.9 years. Orbit 15 period is 3.0714532E7 days or 84093.6 years. Orbit 16 period is 8.6873816E7 days or 237852.8 years. Orbit 17 period is 2.4564128E8 days or 672543.9 years. Orbit 18 period is 6.8631418E8 days or 1879067.0 years. Orbit 19 period is 1.97863962E9 days or 5417339.0 years. Orbit 20 period is 5.5645901E9 days or 1.523535E7 years. Planetary Orbital Periods for star, class A0, of 3.2 solar masses: Orbit 0 period is 18.3 days. Orbit 1 period is 51.7 days. Orbit 2 period is 119.6 days. Orbit 3 period is 204.2 days. Orbit 4 period is 413.2 days. Orbit 5 period is 956.6 days or 2.6 years. Orbit 6 period is 2421.1 days or 6.6 years. Orbit 7 period is 6456.6 days or 17.7 years. Orbit 8 period is 18262.1 days or 50.0 years. Orbit 9 period is 51653.0 days or 141.4 years. Orbit 10 period is 137956.4 days or 377.7 years. Orbit 11 period is 390199.6 days or 1068.3 years. Orbit 12 period is 1103651.1 days or 3021.7 years. Orbit 13 period is 3113998.5 days or 8525.9 years. Orbit 14 period is 8807718.0 days or 24114.7 years. Orbit 15 period is 2.4881614E7 days or 68123.6 years. Orbit 16 period is 7.0375832E7 days or 192682.8 years. Orbit 17 period is 1.9899216E8 days or 544822.8 years. Orbit 18 period is 5.5597805E8 days or 1522218.4 years. Orbit 19 period is 1.60288128E9 days or 4388546.0 years. Orbit 20 period is 4.5078328E9 days or 1.2342044E7 years. Planetary Orbital Periods for star, class B5, of 6.5 solar masses: Orbit 0 period is 12.8 days. Orbit 1 period is 36.2 days. Orbit 2 period is 83.9 days. Orbit 3 period is 143.3 days. Orbit 4 period is 289.9 days. Orbit 5 period is 671.2 days or 1.8 years. Orbit 6 period is 1698.7 days or 4.7 years. Orbit 7 period is 4530.3 days or 12.4 years. Orbit 8 period is 12813.5 days or 35.1 years. Orbit 9 period is 36242.2 days or 99.2 years. Orbit 10 period is 96796.6 days or 265.0 years. Orbit 11 period is 273782.1 days or 749.6 years. Orbit 12 period is 774372.8 days or 2120.2 years. Orbit 13 period is 2184926.0 days or 5982.1 years. Orbit 14 period is 6179903.5 days or 16920.0 years. Orbit 15 period is 1.7458094E7 days or 47798.7 years. Orbit 16 period is 4.9378948E7 days or 135195.2 years. Orbit 17 period is 1.39622144E8 days or 382273.0 years. Orbit 18 period is 3.90099968E8 days or 1068059.0 years. Orbit 19 period is 1.12465587E9 days or 3079207.5 years. Orbit 20 period is 3.16290483E9 days or 8659751.0 years. Planetary Orbital Periods for star, class B0, of 18.0 solar masses: Orbit 0 period is 7.7 days. Orbit 1 period is 21.8 days. Orbit 2 period is 50.4 days. Orbit 3 period is 86.1 days. Orbit 4 period is 174.2 days. Orbit 5 period is 403.3 days. Orbit 6 period is 1020.8 days or 2.8 years. Orbit 7 period is 2722.4 days or 7.5 years. Orbit 8 period is 7700.0 days or 21.1 years. Orbit 9 period is 21778.8 days or 59.6 years. Orbit 10 period is 58167.5 days or 159.3 years. Orbit 11 period is 164522.6 days or 450.4 years. Orbit 12 period is 465340.2 days or 1274.1 years. Orbit 13 period is 1312977.0 days or 3594.8 years. Orbit 14 period is 3713659.8 days or 10167.7 years. Orbit 15 period is 1.049101E7 days or 28723.5 years. Orbit 16 period is 2.9673056E7 days or 81242.2 years. Orbit 17 period is 8.3902464E7 days or 229717.5 years. Orbit 18 period is 2.34420912E8 days or 641823.6 years. Orbit 19 period is 6.7583411E8 days or 1850373.4 years. Orbit 20 period is 1.90066931E9 days or 5203863.0 years. Planetary Orbital Periods for star, class O5, of 40.0 solar masses: Orbit 0 period is 5.2 days. Orbit 1 period is 14.6 days. Orbit 2 period is 33.8 days. Orbit 3 period is 57.7 days. Orbit 4 period is 116.9 days. Orbit 5 period is 270.6 days. Orbit 6 period is 684.8 days or 1.9 years. Orbit 7 period is 1826.2 days or 5.0 years. Orbit 8 period is 5165.3 days or 14.1 years. Orbit 9 period is 14609.7 days or 40.0 years. Orbit 10 period is 39020.0 days or 106.8 years. Orbit 11 period is 110365.1 days or 302.2 years. Orbit 12 period is 312159.7 days or 854.7 years. Orbit 13 period is 880771.7 days or 2411.5 years. Orbit 14 period is 2491198.8 days or 6820.7 years. Orbit 15 period is 7037583.0 days or 19268.3 years. Orbit 16 period is 1.990529E7 days or 54498.9 years. Orbit 17 period is 5.6283488E7 days or 154099.2 years. Orbit 18 period is 1.57254336E8 days or 430548.4 years. Orbit 19 period is 4.53363296E8 days or 1241268.2 years. Orbit 20 period is 1.27500774E9 days or 3490857.2 years.