Epsilon Eridani (star)/meta

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Notes (2016)[edit]

NOTE CONCERNING STAR POSITIONS:

When comparing real-astronomical star positions to the Traveller Map of Charted Space, it needs to be observed that the axes of the Charted Space Map appear to be tilted almost exactly 45o counter-clockwise from the correct position (i.e. "true" Coreward actually lies parallel to the Lesser Rift). If one makes that adjustment, about 70% of the named stars will fall roughly along their correct bearing. However, there are some exceptions in which the star in question lies in roughly the correct position relative to the Charted Space Map without the need to rotate the coordinate axes.

In general, if one is assigning the position of a Real-Universe star to a Traveller Map hex, it should be acceptable if:

1) The star's longitude angle (θ) is within a 45o bearing-arc between the "true" coordinate axes and the Traveller Charted Space Map coordinate axes, and
2) The star's assigned distance from Terra on the hexmap falls somewhere between its true distance R in parsecs, and its 2D-projection onto the flat map as seen from above, found by Dproj = {R * cos(ɸ)}, where (ɸ) is the latitude angle. If desired, the distance above/below the plane can be determined by Z = {R * sin(ɸ)}.



ASTROGRAPHIC NOTES:


Epsilon Eridani system:

  • COMPANION: Planetoid Belt MASS: -- ORBIT: 3.0AU PERIOD: --
  • COMPANION (unconfirmed): ɛ Eri b ("Ægir") MASS: 1.55 MJ ORBIT (Ecc): 3.45AU (e=0.5) PERIOD: ~7 years
  • COMPANION: Planetoid Belt MASS: -- ORBIT: 20AU PERIOD: --
  • COMPANION (unconfirmed): ɛ Eri c MASS: 0.1 MJ ORBIT (Ecc): 40AU (e=0.3) PERIOD: ~280 years
  • COMPANION: Dust Disk MASS: ORBIT: 35AU-100AU PERIOD: --

Infrared observation has shown there are no bodies of 3.0+ MJ in the Epsilon Eridani system, out to at least a 500AU. Planets with similar masses and temperatures as Jupiter should be detectable by Spitzer at distances beyond 80AU, but none has been discovered. Planets > 1.5 MJ can be ruled out at the inner edge of the debris disk at 30−35AU.