Link:
The Trans-Galactic Metallicity Survey
A Distant Worlds 2 Scientific Research Project
The Trans-Galactic Metallicity Survey
A Distant Worlds 2 Scientific Research Project
"From observation, we know the temperature of some stars. We know the size of that star, and we know something called its metallicity, or the types of periodic elements that make up the star’s composition. Some of the older stars actually have very low metallicity, and we factor that into the elements that are there in that specific star system."
- David Braben on the Stellar Forge
Joining the Trans-Galactic Metallicity Survey provides an opportunity for participants to perform real science during the expedition, advancing our understanding of how the Stellar Forge works and how the map of the galaxy it produces matches or differs from real world observation. The method of data collection has been tweaked to eliminate needless procedure and minimize the amount of manual record keeping required.
How does this work?
This Survey works against data in EDSM, but only data of a high enough quality. To guarantee the quality of the data, we'll use data from systems that pilots scan during Distant Worlds 2, following a simple technique:
- Ensure you are set up to upload scan data to EDSM
- Only collect data where the primary star is class F, G, or K
- Scan the primary star and the nearest gas giant, if any
- Keep a list of the systems you scan this way, even if they do not have a gas giant
- Periodically send your list of systems to Satsuma
The result of all this will be a low resolution map of metallicity across the galaxy. As the number of systems scanned grows, we may be able to increase the resolution of this map, examining how metallicity changes as you go up and down from the galactic plane, how it changes in the neutron fields and the zones of suppression, and other artifacts of the Stellar Forge.
TGMS-Bookmarks
I’ve written an EDDiscovery plugin called TGMS-Bookmarks to help make it easier to keep a list of scanned systems. It binds the Scroll Lock key to a routine that creates a bookmark named after a system. These can be copied into a text or Excel file and sent to Satsuma.
Why are we doing this?
Knowledge! We know that the Stellar Forge takes metallicity into account, but we don't have an easy way to see metallicity in game. However, recent research points to a correlation between the mass of a star, the presence of gas giants - both values we can see - and its metallicity.
FAQ
Q: Is there a team for this?
A: This survey is part of the larger Distant Worlds 2 science project. Anyone is welcome to participate, and any amount of data will help! Join us! Let's science the hell out of the Stellar Forge!
Q: Is this for PC players only?
A: While I'll happily take data from console players, there is no easy way to get data from a player's console to EDSM. Some console players have successfully manually input their scan data, but it is extremely labor intensive.
Q: Is there an easier way of keeping lists of scanned systems?
A: If you're an EDDiscovery user, you can use the TGMS-Bookmarks plugin
Background - Optional
The Trans-Galactic Metallicity Survey attempts to infer metallicity on a regional level through statistical examination of scan data. The initial survey will build upon a correlation discovered by astronomers Debra A. Fischer, Jeff Valenti, and Ji . This correlation noted that high metallicity stars are much more likely to have close-orbiting gas giants than low metallicity stars. Since this is a statistical correlation and not an absolute, we cannot use it to determine metallicity of individual stars, but we can examine stellar data over a region and use it to infer the metallicity of the region. The Stellar Forge is known to have used regionwide metallicity data when generating the bodies within a region, so it is my hope that this survey will result in meaningful data.
Sample data:
| Region | Nsys | Ngg | P = Nsys/Ngg | Metallicity | Confidence |
| Eol Prou | 877 | 73 | 0.083 | low | moderate |
Initial metallicity data of the Eol Prou region, centered around Y = -700. Data courtesy of Taen
Nsys = Number of star systems
Ngg = Number of gas giants
This sample data details a region outside of the central bulge of the galaxy (Colonia), far enough away from the galactic plane that it compromises a boundary between the thin and thick galactic disks. We could expect metallicity to be low in this area, and it is.
Nsys = Number of star systems
Ngg = Number of gas giants
This sample data details a region outside of the central bulge of the galaxy (Colonia), far enough away from the galactic plane that it compromises a boundary between the thin and thick galactic disks. We could expect metallicity to be low in this area, and it is.
Last edited:
Anyway, thank you in advance, and fly safely in the black...
![mtt9999 [Parabolus]](https://d2aefvhu2f0gi9.cloudfront.net/data/avatars/m/124/124206.jpg?1553527149){kind=avatar}
