Suppose for the moment one is a science fiction writer. Further suppose one’s setting is on an interstellar scale and one wants to incorporate real star systems and their exoplanets. Are there pitfalls to consider?
Aside from the very obvious one with which I will lead…
There is a tendency among some SF writers to use familiar stellar names such as Rigel, Vega, or Achernar. I am never sure whether this is for marketing reasons—readers will likely have heard of at least two of those—or if the issue is that those are the only stars with whose names some SF authors are familiar.
The catch is that named stars tend to be the visible ones. Sunlike stars are not naked-eye visible beyond ten parsecs or less, a volume that contains only a handful of visible stars. Most named stars are distant, bright, and thanks to the way stars work, too short-lived to be likely hosts for naturally-occurring Earthlike life-bearing planets1.
If you are going to use the name of a bright feature in the sky, it’s a good idea to check to make sure that object is actually a star and not, say, a nebula, galaxy, or globular cluster—or at least, be aware that the bright object is a nebula, galaxy, or globular cluster. Iain M. Banks’ Use of Weapons provides an amusing (entirely intentional) example, when its protagonists go haring off to “Crastalier,” assuming that’s a planet, which it is not, and not an open cluster with half a million stars, which it turns out to be.
I should further note that the apparent positioning of the stars in the sky is dependent on one’s location. As one moves away from Sol, the relative positions of the stars will appear to change. One easy way to provide local flavor is by revealing, subtly or otherwise, that the planet of interest has created its own constellations, as Earth’s are of no relevance to what they see in their sky.
If you’re planning on incorporating constellation-based names, familiarize yourself with the nomenclature. Take Alpha Centauri, for example, the constellation in which it is located is Centaurus2. The Greek letter indicates its apparent brightness compared to the other stars of that constellation. It’s not a star called Centauri located in the Alpha constellation.
Due to the visibility issue mentioned above, only a very small number of sunlike stars have proper names. Only a few rate Greek letter + constellation names. This means there are many potentially interesting systems whose current designations are a catalog name and a number, and a few that definitely look like they were named by banging an astronomer’s head on a keyboard.
There is nothing wrong with using actual catalog names—it shows you did your homework—but it seems likely anyone living in the cd-69 2001 system will want a more euphonious name.
The current convention for naming exoplanets makes sense from the perspective of astronomers on Earth: a star’s exoplanets are given a lower-case letter designation in the order they are discovered (a, b, c, etc.). While this means the known exoplanets don’t have to be renamed every time a more inward exoplanet is found, it does mean that the lower-case letter designation provides no useful information about the position of the exoplanet within the system. 55 Cancri provides a nice example: 55 cnc b is further from its sun than 55 cnc e.
No offense to astronomers, but this looks like the sort of arrangement that ultimately forces a grand renaming, probably around the time astronomers become confident they’ve spotted all the exoplanets in a particular system. I expect such a renaming will go as smoothly as USENET’s Great Renaming3. Anyway, if you’re using the current system—again, it shows you did your homework—don’t assume “b” will be closer to its star than “c.” It might be, but it also might not.
These are just a few of the nomenclature issues inherent to using actual star systems in SF. No doubt you have your own favorites4 I’ve overlooked. Feel free to discuss them at length in comments below.
