IGC S-83,938,253. Perseus Arm, Columbian Sector.
Sallos A,B. Stellar class: both F9, radius: 1.07 Sol, radius: 1.14 Sol, luminosity: 1.9 Sol.
Estimated time remaining on the main sequence: 3.5 x 109 years.
Planetary System: Seven major planetary bodies . . .
V, Dis. Mean orbital radius = 4.85 a.u.,
period = 10.004 years.
Orbital eccentricity = .0312.
Apastron = 5.00132 a.u.; periastron = 4.69868 a.u.
Equatorial diameter = 198,673 km.
Density = 1.034 g/cm3.
Surface gravity = 2.92 G.
Axial tilt = 2.03º.
Rotational period = 9h 12m 27.112s.
Magnetic field = 6.4 gauss.
Atmosphere: H2, 84% +/- 3%; He, 16% +/- 3%; CH4, 0.15%; NH3, 250 ppm; C2H6, 15 ppm; H2O, 2 ppm; HCN, .08 ppm; C2H2, .034 ppm; CO, .003 ppm; GeH4, .0004 ppm.
Satellites: 25 with diameters > 100 km, 3 with diameters > 5,000 km. . . .
One major satellite, Caern, is of special note. . . .
Satellites: Sallos Vf, Caern.
Orbital semimajor axis = 1,002,354 km, rotational period = 4d 8h 46m 6.87s,
orbital eccentricity = .0004. . . .
Equatorial diameter = 8368 km.
Density = 6.228 gm/cm3.
Surface gravity = .74 G.
Planetary mass = 1.91232 x 1027 g.
Axial tilt = 0.04o.
Rotational period = tidally locked at 4d 8h 46m 6.87s.
Magnetic field = 1.21 gauss.
Surface area = 219,985,074.4 km2.
Surface temperature: 12% of incidental thermal radiation is derived from the primary.
Temperature = locationally variable, -30o C.
(anti-Dis side) to 50o (sub-Dis point).
A habitable band exists between the hemispheric regions of permanent ice and desert.
Atmosphere: Mean surface pressure 0.8 bar.
N2, 77.08%; O2, 21.04%; Ar, 1.02%, H2O, 0.05-1.5% (mean 1%); CO2, 350 ppm; Ne, 12.2/ppm; He, 6.34 ppm; CH4, 1.9 ppm; Kr, 1.98 ppm; CO, 1.3 ppm; SO2, 3.4 ppm; H2, 0.4 ppm; N2O, 0.33 ppm;
O3 .05-1.9 ppm; Xe, 0.09 ppm; NO2, 0.03 ppm.
Notes: A habitable satellite of the gas giant Dis with its own native biosphere, Caern was colonized by Terran-human stock late in the Concordiat age. Military depots and communications centers at Paimos and Grendylfen gave the planet some minor strategic import in that struggle, but the system was located far from major areas of conflict and not directly involved in the fighting. Cut off from all contact with human space during the final phase of the Melcon Armageddon and the subsequent Dark Era, Caern was eventually absorbed as an outpost of the then-unknown Aetryxha Reach. Recontact with Caern in cy 375 has led to a period of steadily escalating tension between the Confederation and the Reach. . . .
Space Navigator's Ephemeris
Confederation Technical Press
37th Edition, cy 378
Six Confederation naval vessels, huge, irregularly patterned in swaths and stripes of black, gray, and blue, decelerated into Disian space, weapons charged, spiked snouts clawing at the clotted stars. Ahead, the ringed, back-lit globe of the gas giant loomed vast within its necklace of crescent moons. Sallos A and B, the local suns, glowed hot, white, and arc-light dazzling, made tiny by distance.
On board the battlecarriers Esan and Helias, the command cruiser Galahedron, and the three destroyers that made up the battle group, nearly ten thousand Confederation naval personnel waited at their stations, waited to see what shape the Aetryx response to their arrival in-system would take. At this point, little was known of the aliens. All that could be said with certainty was that their reaction would likely be . . . alien. In truth, little of the xenosophontological reports garnered thus far from the planetside merchant factors and X-Corps scouts made sense. Making sense out of the situation—and ascertaining the fate of some hundreds of millions of humans resident on Caern—was the Battlecarrier Task Force's primary mission.
Officially, the BTF was engaged in what was euphemistically termed "diplomatic service." The military forces of another age and place might have called it a show of force, or even "gunboat diplomacy." The Aetryx Circle had defied the Confederation Senate. Millions of humans living on Caern languished in alien slavery. Admiral Cellini, commanding BTF-74, was determined that there would be a full accounting.
At the very least, they would get the Aetryx to talk. . . .
And then everything started going wrong.
Dazzling flares of silent light erupted in the darkness. Space fighters, sleekly streamlined and knife-blade deadly, streaked through the Confederation squadron, loosing missiles, Hellbore bolts, and high-velocity kinetic-kill projectiles. Thermonuclear horror engulfed the Helias, vaporizing her aft works and sending the rest, accompanied by glittering fragments, pinwheeling into the night. Hellbore fire sliced through the bridge and primary turret decks of the destroyer Calavas, until her crew modules erupted in a spray of liquid metal and hard X-rays.
Orders snapped from the Galahedron. Firing at their attackers in barrage upon barrage of disciplined chaos, the surviving members of the squadron accelerated. The laws of physics being what they were, to continue deceleration until they could return the way they'd come was suicide, plain and simple. Their only hope lay in maintaining their course, whipping past Caern and giant Dis and outrunning their ambushers until they could again slip into the relative safety of hyper.
Another volley of incoming kinetic-kill missiles loosed shattering radiance within the infalling coterie of warships, peeling back armor in half-molten strips, shattering the hull of the destroyer Tubek. The battlecarrier Esan shuddered as multiple warheads vented their hellish fury scant kilometers from her hull; battlescreens failed, and a second volley sent a storm of hard gamma radiation sleeting through her crew modules. Every man and woman aboard was dead when the leviathan vessel detonated as a tiny sun minutes later.
The surviving vessels were clear of the first onslaught now and racing for the minimum distance beyond the local gravity well where they could kick over into hyper and vanish. Dis wielded an immense influence over local space, however, and at maximum acceleration, Galahedron and the destroyer Kurbal would need another hour at least to work their way clear.
The second flight of needle interceptors raced in from a quartet of Aetryx battlecarriers in close orbit over Caern . . . blunt-nosed penetrators flashing in at accelerations so high they could only be robotic or manned by suicide crews. Galahedron survived until she was sweeping in periplanetos past Dis, skimming the hydrogen fringe of the gas giant's upper atmosphere . . . and then a barrage of missiles hunted her down in a blaze of thermonuclear fury. The radiation storm touched the hurtling Kurbal, burning out secondary drives and knocking her weapons off-line, but her captain kicked in auxiliaries to stabilize her fall and let the massive gravitational drag of Dis slingshot his hell-scorched vessel clear of the planet. The interceptors followed but were too far astern now to have a chance of closing to complete their kill. Ninety-eight minutes after the engagement began, Kurbal slipped into hyper, the sole survivor of BTF-74.
Admiral Cellini had been sister-in-law to the Senate president. The firestorm that erupted within the Confederation Senate upon Kurbal's return to her base at Endymion far surpassed the pyrotechnics that attended the destruction of the Galahedron.