Sigma Draconis is a K0 V orange star 18 light-years from earth in the
constellation Draco. It is both smaller and cooler than Sol,
and
slightly metal-poor.
It is one of the least variable stars measured to date, and
has
an unusually eccentric galactic orbit (0.3 eccentricity, compared to
Sol's 0.06).
It
has a large solar system of thirteen planets, including one earth-like
world (IV - Asherah) and another which may be a suitable prospect for
terraforming (VI - Wigaunt). The planets were named by the
astronomers who
discovered their existence using the initial survey probe results.
Kaleda, Sinmore, and
Benisa
(Sigma Draconis I-III)
The inner three worlds of the Sigma Draconis system are all small,
airless, rocky worlds that are tidally locked to the star.
Kaleda
is a little smaller than Luna, and much less massive. Sinmore
is
about half the size of Earth and 12% of it's mass. It is
named
after the Queen of Muspelheim (Norse realm of Fire) and the
wife
of the Norse god
Surt
in Wagner's Götterdämmerung. Benisa is a
bit
larger than Kaleda and four times as massive.
Asherah (Sigma
Draconis IV)
Overview
The only truly habitable planet in the system. Asherah is a
water
world, with a chilly and damp climate almost year-round at most
latitudes, due to the relative dimness of the host star and the slight,
eight degree axial tilt. Temperature
ranges from an average of 27.8 degrees fahrenheit at night
to 51.5
degrees in the day (-2.3 to 10.8 deg C). The weather tends
toward
dense morning/evening fog and bleak, overcast days at all but the
equatorial and polar latitudes. The day is just short of 20
standard hours in length.
The surface of the planet remains largely unexplored. It
consists
of a handful of smallish continental and subcontinental landmasses, and
a large number of smaller islands.
Asherah has two moons, Threnody and Terpischore, both of which appear
larger in the sky than Luna (Threnody, the larger and closer of the
two, covers 1.38 angular degrees, about 2.75 times as large as
Luna). Thanks to its moons, Asherah has stronger and more
complex
tides than earth, and total eclipses are fairly commmon.
Native Ecology
There is no known sapient life on the planet, but there are a number of
interesting subsapient life forms.
One peculiarity of Asherah's ecosystem is that the plant kingdom has
evolved many of the characteristics and fills many of the niches
usually held by animals on other worlds, including mobility (many of
the floral organisms are non-sessile for at least part of their
lifespan), and even limited intelligence. The Kukta, for
example,
is a perennial flowering organism roughly analogous to a dog or cat,
which is easily
domesticated and makes a loyal and well-behaved pet. Kukta
are low-maintenance, requiring only sufficient water,
sunlight, and a fairly wide range of soil conditions, and
house-breaking is never a problem. They also smell nice and
are a riot of color when they bloom.
Visitors would be well-advised to familiarize themselves with the more
dangerous known predatory plant species before arrival.
Arien (Sigma Draconis V)
This planet seems to be the core of a failed Jovian world, and the
innermost of three planets that are unusually inclined to the plane of
the rest of the system. Astronomers suggest that some
ancient catastrophe stripped Arien of much of its atmosphere
and
placed Wigaunt into a more eccentric orbit.
Wigaunt (Sigma
Draconis VI)
Aside from Asherah, Wigaunt is probably the best prospect for
colonization in the Sigma Draconis system. It is somewhat
more
hospitable than Mars, having a surface gravity of nearly half a
standard g, and a correspondingly thicker atmosphere (thin, but
breathable).
The planet is, however, rather cold. The "continental"
plateaus
and poles are entirely frozen over, resulting in a 43% ice
cover.
The "ocean floors" are considerably warmer, due to geological activity,
enough so to support small plant life.
Skall (Sigma
Draconis VII)
An ice world, too cold to be
very hospitable. It has a thick atmosphere that refracts light
strongly. Seen from space, the night side of the planet is
encircled by a brilliant orange sunset.
Barrilock (Sigma
Draconis VIII)
One of three Jovian worlds in this system.
Elyon (Sigma
Draconis IX)
A Jovian world, the largest in the system. The name means
"Most High". An unusual thermal inversion structure in Elyon's
upper atmosphere traps two layers of tiny particles that serve as a
sort of planetary fibre-optic network, channelling some of the sunlight
from the day side around to the night, making the dark clouds
radiate a dull red light.
Scrokallan (Sigma
Draconis X)
The third of Sigma Draconis's three Jovian worlds.
Enmassara (Sigma
Draconis XI)
A golden subjovian planet, just under three earth masses, but several times as
large.
Tinati (Sigma Draconis
XII)
An airless, rocky planet. Tinati is about 80% of the size of
the
earth, but has only a third of the surface gravity.
Rinn (Sigma Draconis
XIII)
A large but light body far out on the outskirts of the system.
It
takes over 330 earth years to complete a single orbit. Like
Arien
and Tinati, Rinn is strongly inclined to the plane of the other
planets in the system.
