Fomalhaut (star)/meta
NOTE CONCERNING POSITIONS OF STARS AND CELESTIAL OBJECTS :
When comparing real-astronomical celestial object 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 about 45o counter-clockwise from the correct position (i.e. "true" Coreward (in the direction of Sagittarius A*) actually lies in the general direction of the Lesser Rift; "true" Rimward falls directly on a bearing towards the star Capella). If one makes that adjustment, about 70% of the named stars and celestial objects 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.
Thus, if one takes a straight-edge and draws a line thru Sol/Terra and Capella, astronomically speaking you have drawn a precise Coreward-Rimward axis-line.
In general, if one is assigning the position of a Real-Universe star or celestial object to a Traveller Map hex, it should be acceptable if:
- 1) The object'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 object'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)}.
- Please also see the entry: Miller Projection (Astronavigation) excerpted from Journal of the Travellers' Aid Society volume 7 (Mongoose Publishing, 2023), p. 71-80 by Dalton Calford
NOTE CONCERNING SPECTRAL CLASS & HUE:
Spectral classification is an indication of the temperature of the stellar surface and originated in the typical chemical composition observed (primarily the brightness/dimness of hydrogen lines in the emission spectrum: from "A" (strongest) to "O" (weakest) before the temperature/chemical relationship was understood). The O,B,A,F,G,K,M "color" classification is traditional, and based on observation thru earth's specific atmosphere, not actual appearance in vacuum. Truly "pinkish-red" to "cherry-red" stars would be a few late M-type stars and L-Type thru T-Type Brown Dwarfs, as well as CR, CN and S type giant stars "Carbon Stars" which are a ruby-red coloration due to chemical composition oddities.
ASTRONOMICAL NOTES:
- The star Fomalhaut A is surrounded by several debris disks. The inner disk lies at about 0.1 AU from the star, with the inner edge of a second disk lying at 0.4-1.0 AU from the star. The outermost disk lies at a distance of 133 AU in a belt about 25 AU wide (and is sometimes referred to as "Fomalhaut's Kuiper belt").
- The planet Fomalhaut b is a confirmed and directly imaged extrasolar object orbiting the star Fomalhaut A. The object was initially announced in 2008 and confirmed as real in 2012 from images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. According to calculations it has a 1,700-year, highly elliptical orbit with a periastron of ~50 AU and an apastron of about ~300 AU. The mass of Fomalhaut b is estimated to be anywhere between 1.0MEarth and 2.0 MJupiter. It has officially been given the name Dagon by the IAU.
- Observations of the star's outer dust ring by the Atacama Large Millimeter Array point to the existence of two planets in the system, neither one at the orbital radius proposed for the HST-discovered Fomalhaut b.
- If there are additional planets from 4 to 10 AU, they must be under 20 MJ; if from 2.5 outward, then 30 MJ.
- Fomalhaut A System:
- COMPANION: Inner Hot Disk ORBIT: 0.08–0.11AU
- COMPANION: Outer Hot Disk ORBIT: 0.21–0.62AU -or- 0.88–1.08AU
- COMPANION: 10AU Belt ORBIT: 8-12AU
- COMPANION: Interbelt Dust Disk ORBIT: 35-133AU
- COMPANION: Fomalhaut b ("Dagon") MASS:(?) MJ ORBIT (Ecc): 177AU (e=0.8) PERIOD: ~1700 years
- COMPANION: Main Belt ORBIT: 133-158AU
- COMPANION: Main Belt Outer Halo ORBIT:158-209AU
- The star Fomalhaut C is surrounded by its own independent debris disk.
- Fomalhaut C System: COMPANION: Debris Disk ORBIT:10-40AU