Luyten 726-8 AB

'Luyten 726 AB.

The Luyten 726-8 AB star system is a binary red dwarf flare stars approximately 2.63 pc or 8.57 light-years from Earth's Solar System, in the constellation Cetus, and is thus the sixth closest star system to Earth. Its own nearest neighbour is Tau Ceti, 0.88 pc or 2.87 light-years away from it.

Overview

BL Ceti (Luyten 726-8 A) is also catalogued as G 272-061. Claimed by ZMI 193 standard years ago its colonisation was marked with dificulties and with the extreme flare activity, variable gravity and high levels of ambient radiation, and a tiny and highly variable inhabitable zone making it unsuitable for conventional industrial nodes or freefloating low maintenance colonies to be established. Although both stars are Flare stars, the fainter member of the system is considered to be an extreme example; it has been given the variable star designation UV Ceti but is also referred to as "Luyten's Flare Star".

Company Involvement

The extreme conditions in the Lutyen system have left a uniquely high quantity of fissile materials, and exotic materials in its debris belts. Original scouting 204 standard years ago by the ZMSF “Tacit Traveller” along with the observed characteristics of the binary system left the Lutyen system far down on any list of possible exo solar assets however further spectroscopic and geological probing of in system minor bodies proved that the melting pot that was the Luyten system had cooked up ore bodies of great value and concentration. Primary colonisation and industrialisation efforts began in earnest 123 years ago with the establishment of the Perdition colony.

Primary ZMI bases are situated in the cometary halo (far closer than sol’s cometery halo given the lower primary size) with the largest stable dark body at a diameter of 6,200 kilometres Perdition presently having no more than 1,380,000 inhabitants within a sub surface colony Sorrenson City. System wide population is no more than 3.8 million with the bases outside the worst flare zones support a wide number of automated extraction platforms which operate within the flare zone and act as primary refining sites safely outside any “rip tide” like effects created by the binary system. Many of the exotic materials are used in transit drive construction and as such a full fleet task force is at all times on station with several fixed ZMSF bases on bodies throughout the system with a fleet support station in permanent orbit of Perdition. The Luyten’s system is used as a final testing ground for the ZMSF with vessels run through the gap between the binary as a final “crack up” test and has been used to stage a number of flare generating weapons tests with regular artificial flares generated every 3.8 years in A and every 2.73 years in B to lower the chance of any major eruption.

The system for its first 23 standard years of operation was reliant on external sources of bio mass, however the rapid construction program and a large number of CHON conversion platforms Luytens is now a net exporter of advanced synthetic food stuffs. The corner stone of the system wide economy however remains the export of large quantities of use ready fissile materials.

The Luytens system is governed by the locally elected autonomous body known as the Perdition Council however it is still nominally a ZMI territory.

BL Ceti (L 726-8 A)

This cool and dim, main sequence red dwarf (M5.6 Ve) is 11 percent of Sol's mass 14 percent of its diameter , and less than 6/100,000th of its luminosity . Although less dramatic in its brightness variations than its binary companion B, Luyten 726-8 A has also been identified as a flare star. Star A and its companion UV Ceti have a combined mass of about 20 percent of Sol's but less than 11/100,000th of its brightness. The two stars are separated "on average" by only about 5.5 times the Earth-Sun distance (AUs of a semi-major axis) in a highly elliptical orbit (e= 0.62), at an inclination of 127.3° degrees. The two stars swing between 2.1 and 8.8 AUs apart in an orbital period lasting 26.5 years. Like its companion, Star A is also a variable and flare star, designated BL Ceti.

UV Ceti (L 726-8 B)

This often even dimmer, main sequence red dwarf star (M6.0 Ve) has only 10 percent of Sol's mass , 14 percent of its diameter, and less than 4/100,000th of its luminosity. However, UV Ceti is an extreme example of a flare star that can boost its brightness by five times in less than a minute, then fall somewhat slower back down to normal luminosity within two or three minutes before flaring suddenly again after several hours. In 1952, UV Ceti was observed flaring to 75 times its normal brightness in only 20 seconds.

Observation data

Epoch J2000
Constellation Cetus
Right ascension 01h 39m 01.3s
Declination -17° 57' 01"
Apparent magnitude (V) 12.54/12.99

Characteristics

Spectral type M5.5 V/M6 V
B-V color index 1.87/?
U-B color index 1.10/?
Variable type Flare Stars

Astrometry

Radial velocity (Rv) +29.0 km/s
Proper motion (μ) RA: 3.321"/yr
Dec.: 0.562"/yr
Parallax (π) 0.37370" ± 0.00270"
Distance 8.72 ly (2.676 pc)
Absolute magnitude (MV) 14.92/15.37

Visual binary orbit

Companion Luyten 726-8 B
Period (P) 26.5 years
Semimajor axis (a) 1.95"
Eccentricity (e) 0.62
Inclination (i) 127.3°
Node (Ω) 150.5°
Periastron epoch (T) 1971.91

Details

Mass 0.10/0.10 M☉
Radius 0.14/0.14 R☉
Luminosity 0.00006/0.00004 L☉
Temperature 2,670 K

Other designations

BL Ceti/UV Ceti, GCTP 343.10 A/B, LHS 9/10, GJ 65 A/B.