Post by: Steve Walmsley on September 06, 2009, 09:02:52 AM
I began my latest campaign a few days ago with 12 starting races. Everyone was naming the systems differently, which is usually a good thing because it helps me to maintain a sense of attachment to that particular race when making decisions for them. However, with the number of races and the fact that several of them were allied anyway and sharing grav and geo data, it was a little confusing. So I decided to add fixed names for system. They are set on the F9 window and any new race finding the system will use that name, although this can be overriden by renaming it or using the auto-rename (which I might have just added). Then I decided to start using the names of real star systems. To make it more realistic I looked up the star types of nearby systems and tried to match existing stars to the stars already generated in the game. Then a light-bulb went on and it occurred to me I was doing this the wrong way round. Instead of generating Aurora systems and matching them to real star systems, I should use the real star systems as the basis for generating Aurora systems.
I have set it up as an option for Aurora to take system parameters from the database, including the type of each star and the orbital distances, and then generate the system from that point. So for example, if you generate Alpha Centauri the program will start with a G2V star and a K1V companion 23 AU apart and then begin its usual system body generation. The system will also be given the fixed name of Alpha Centauri so that any Earth-based powers will immediately recognise it. If you generated Wolf 359, it would be a single M6V red dwarf, while Tau Ceti is a G8V, etc. When you run a new campaign, you will still get the same star systems but the planetary systems around each star could be completely different.
At first I was going to generate them in rough distance from Earth so as you explored you would encounter stars further away. The mechanics were that the program would order the stars by distance from Sol and then run through the list, using a 20% chance for each until one was selected, which would randomise the discovery order while retaining the idea of near stars first. Then I had another light bulb go off :)). Deneb is an A2I supergiant, Rigel is a B8Ia supergiant, Betelgeuse is an M2Ia supergiant, Antares is an M1Ia supergiant, Arcturus is a K2III giant, Aldebaran is a K5III giant, etc.. So far, I have added about 180 systems to the DB and they are a mixture of stars close to Sol, which include a lot of smaller stars, nearby brighter stars out to 50 LY, which includes a lot of K and G classes and the occasional A, and the larger well known stars out to about 1000 LY, which are all giants or very bright O and B types. This could possibly create a strange situation with generally larger stars discovered as the game goes on. Therefore, I will be adding a lot more stars from the various stellar catalogues to fill it out. These won't be as well known but they will be real stars and they will make the distribution of star types more realistic.
If anyone has their own favourite stars (or has named one for their wife/girlfriend
), let me know and I will include it in Aurora's DB.Steve
Post by: welchbloke on September 06, 2009, 05:54:00 PM
Quote from: "Steve Walmsley"
Some background on my rambling thought process...Steve, Cool!
I began my latest campaign a few days ago with 12 starting races. Everyone was naming the systems differently, which is usually a good thing because it helps me to maintain a sense of attachment to that particular race when making decisions for them. However, with the number of races and the fact that several of them were allied anyway and sharing grav and geo data, it was a little confusing. So I decided to add fixed names for system. They are set on the F9 window and any new race finding the system will use that name, although this can be overriden by renaming it or using the auto-rename (which I might have just added). Then I decided to start using the names of real star systems. To make it more realistic I looked up the star types of nearby systems and tried to match existing stars to the stars already generated in the game. Then a light-bulb went on and it occurred to me I was doing this the wrong way round. Instead of generating Aurora systems and matching them to real star systems, I should use the real star systems as the basis for generating Aurora systems.
I have set it up as an option for Aurora to take system parameters from the database, including the type of each star and the orbital distances, and then generate the system from that point. So for example, if you generate Alpha Centauri the program will start with a G2V star and a K1V companion 23 AU apart and then begin its usual system body generation. The system will also be given the fixed name of Alpha Centauri so that any Earth-based powers will immediately recognise it. If you generated Wolf 359, it would be a single M6V red dwarf, while Tau Ceti is a G8V, etc. When you run a new campaign, you will still get the same star systems but the planetary systems around each star could be completely different.
At first I was going to generate them in rough distance from Earth so as you explored you would encounter stars further away. The mechanics were that the program would order the stars by distance from Sol and then run through the list, using a 20% chance for each until one was selected, which would randomise the discovery order while retaining the idea of near stars first. Then I had another light bulb go off :)). Deneb is an A2I supergiant, Rigel is a B8Ia supergiant, Betelgeuse is an M2Ia supergiant, Antares is an M1Ia supergiant, Arcturus is a K2III giant, Aldebaran is a K5III giant, etc.. So far, I have added about 180 systems to the DB and they are a mixture of stars close to Sol, which include a lot of smaller stars, nearby brighter stars out to 50 LY, which includes a lot of K and G classes and the occasional A, and the larger well known stars out to about 1000 LY, which are all giants or very bright O and B types. This could possibly create a strange situation with generally larger stars discovered as the game goes on. Therefore, I will be adding a lot more stars from the various stellar catalogues to fill it out. These won't be as well known but they will be real stars and they will make the distribution of star types more realistic.
If anyone has their own favourite stars (or has named one for their wife/girlfriend
Steve
Are you using your own set of XYZ co-ord or are you using a standardised database from another source? There is a system called the galactic co-ordinate system that may be of use if the catalogues you are using give the stellar positions in this format. Also, there are several websites on the internet that will change celestial to galactic co-ordinates. I thought it may be easier for you to calculate relative positions if they all use the same co-ordinate system.
Post by: Steve Walmsley on September 06, 2009, 07:33:30 PM
Quote from: "welchbloke"
Steve, Cool!I am using data from several sources but mainly the HYG database: http://astronexus.com/node/34 (http://astronexus.com/node/34) and the Internet Stellar Database: http://www.stellar-database.com/ (http://www.stellar-database.com/), plus some sources on Wiki and the major Star Catalogue sites. The main problem is that there are at least a dozen different catalogues and each one uses different names for the same stars. Not every star is in every catalogue and they disagree on spectral types and sometimes location. They also differ on whether a star is a single star or a close binary. Some include orbital data for secondary stars and some just list them separately. It's been something of a major research task figuring out which is which
Are you using your own set of XYZ co-ord or are you using a standardised database from another source? There is a system called the galactic co-ordinate system that may be of use if the catalogues you are using give the stellar positions in this format. Also, there are several websites on the internet that will change celestial to galactic co-ordinates. I thought it may be easier for you to calculate relative positions if they all use the same co-ordinate system.
The coordinates are based on data in the HYG and ISDB. The former uses parsecs and the latter light years and they disagree a little but its close enough.
Steve
Post by: welchbloke on September 06, 2009, 07:55:07 PM
Quote from: "Steve Walmsley"
Quote from: "welchbloke"Steve, Cool!I am using data from several sources but mainly the HYG database: http://astronexus.com/node/34 (http://astronexus.com/node/34) and the Internet Stellar Database: http://www.stellar-database.com/ (http://www.stellar-database.com/), plus some sources on Wiki and the major Star Catalogue sites. The main problem is that there are at least a dozen different catalogues and each one uses different names for the same stars. Not every star is in every catalogue and they disagree on spectral types and sometimes location. They also differ on whether a star is a single star or a close binary. Some include orbital data for secondary stars and some just list them separately. It's been something of a major research task figuring out which is which :( I'm not surprised that the distances and method of cataloging are at odds with each other. The distance variations will be due to simple things like the sophistication and type of sensor. It has been my experience of people who work in the space industry (astrophysicists and engineers) that they generally assume that their method is simpler and that everyone should understand it
Are you using your own set of XYZ co-ord or are you using a standardised database from another source? There is a system called the galactic co-ordinate system that may be of use if the catalogues you are using give the stellar positions in this format. Also, there are several websites on the internet that will change celestial to galactic co-ordinates. I thought it may be easier for you to calculate relative positions if they all use the same co-ordinate system.It can also be said that if you put 10 astrophysicts in a room and ask them a question you will get at least 12 answers!
Post by: Steve Walmsley on September 06, 2009, 10:36:30 PM
Steve
Post by: IanD on September 07, 2009, 02:48:55 AM
Absolutely brilliant! As many have said the game just gets better and better!
When can we expect 4.27 with the stellar database?Regards
Post by: Steve Walmsley on September 07, 2009, 03:05:27 AM
Quote from: "welchbloke"
Sounds like you've already done the hard work I'm a little late in suggesting using galactic co-ordinates :D It can also be said that if you put 10 astrophysicts in a room and ask them a question you will get at least 12 answers!I did wonder whether to use Celestial or Galactic but in the end went for Celestial because while the ISDB had both, the much more extensive HYG database used the latter. Unfortunately the ISDB has orbital distances for binary stars, which the HYG doesn't, although it just occurred to me that with the detailed coordinates calculated from the Hipparchus data, I should be able to work out the orbital distance myself. It will be the current distance rather than the semi-major axis but that should suffice.
Steve
Post by: IanD on September 07, 2009, 07:49:26 AM
I assume you have seen the site below?
http://www.projectrho.com/smap06.html (http://www.projectrho.com/smap06.html)
Regards
Post by: waresky on September 07, 2009, 09:03:32 AM
this drive us deeep and deep into a "real-feel" in a"Real Galaxy"..
slurp slurp..when come this New Dream Era?:))))
Post by: Steve Walmsley on September 14, 2009, 06:23:06 PM
Quote from: "IanD"
SteveYes I have but thanks for the link. I got a couple of my sources of information from there. A very useful site indeed.
I assume you have seen the site below?
http://www.projectrho.com/smap06.html (http://www.projectrho.com/smap06.html)
Number of real systems in the Aurora database is now up to 750. I have done little else for the last week but research star systems and add them to the DB :)
Steve
Post by: welchbloke on September 14, 2009, 08:51:46 PM
Quote from: "Steve Walmsley"
Well uber-geek or not you appear to amongst freinds hereQuote from: "IanD"SteveYes I have but thanks for the link. I got a couple of my sources of information from there. A very useful site indeed.
I assume you have seen the site below?
http://www.projectrho.com/smap06.html (http://www.projectrho.com/smap06.html)
Number of real systems in the Aurora database is now up to 750. I have done little else for the last week but research star systems and add them to the DB :)
Steve
Post by: Steve Walmsley on September 29, 2009, 04:23:01 PM
22nd May 2029
Newton completed readings at one of the outermost survey locations, the same distance as Pluto from Earth, and detected a sixth jump point eight hundred and fifty million kilometers away. This one however had a jump gate! Construction of such gates was already being researched so the technology itself was not the most startling revelation, However, the immediate question was that as humans didn't build the gate, who did and were they still around? Newton was ordered to investigate and the European gravitational survey ship Planck, 2.8 billion kilometers away around and at a similar distance from Sol, was also diverted to the new jump point. Both Japanese survey ships were on the far side of the system so they were unable to investigate for the moment. On Earth, discussions began regarding defensive preparations in case the gate builders returned.
25th May 2029
Newton arrived at the gate's location. The primary concern at this point was that Newton was not jump-capable and therefore if there was no matching gate on the far side, she would be unable to return. The Coalition and the European Union had both recently completed designs for jump engines suitable for ships of up to 3750 tons and the Japanese were close to completing their own design. It would take many months though to design a jump ship, retool the shipyards and build the first jump-capable ship so Newton could be stuck light years from home for a year or more. Nevertheless, CMDR Kian Fraser and crew were keen to try and the majority view among Coalition scientists was that it would be strange indeed if an alien race only built a jump gate on one side of a jump point.
Newton emerged in a binary star system comprising two red dwarfs approximately 157 AU apart - about four times the distance from Earth to Pluto. Based on spectral analysis of the stars, the system was quickly identified as Groombridge 34, located eleven point six light years from Earth in Einsteinian space. Both stars had planetary systems, with a mixture of gas giants, several of which had extensive moon systems, and smaller, rocky worlds. The primary also had a scattered asteroid belt ranging between two and four billion kilometers. The jump point, which fortunately had a matching jump gate to the one in Sol, was located within the belt, at 2.86 billion kilometers. While the innermost planets of both stars had dense Venus-like atmospheres of carbon dioxide and Nitrogen Dioxide, the only system body of real note was Groombridge 34-B II, the second planet of the companion star. Located just twenty-one million kilometers from the star, it had an atmosphere of Nitrogen, Oxygen and Argon, although the oxygen content was just three percent and the atmosphere itself only seventy percent the density of Earth's so it wasn't breathable. The average temperature was -27C and liquid water was present on the surface. While not exactly a new Earth, it was an encouraging sign that Earth-like planets might be found in other nearby systems. Newton returned to Sol with her news.
20th October 2030
Redoutable - the first jump-capable ship - was launched by the EU. She begain a tour of the known jump points.
Jump Point One led to Alpha Centauri. A binary system with a G2V primary, very similar to Sol, and a K1V companion at almost three point five billion kilometers. Alpha-Centauri-A had only one planet, a Venusian world located within thirty million kilometers. Alpha Centauri-B was far more exciting: Six planets, the second of which orbited at 70 million kilometers and was immediately habitable. Alpha Centauri-B II was slightly larger than Earth with a higher density, giving it a gravity of 1.35G. While any colonists would feel a third heavier than normal, they would acclimatize over time. The atmosphere was also denser by about nine percent and the oxygen content was higher at around 0.25 atm. Average temperatures were lower but well within human tolerances. The jump point in Alpha Centauri was four point two billion kilometers from the primary and almost six billion from Alpha Centauri-B. However, within twenty-five years the orbit of the companion star would pass within seven hundred million kilometers of the jump point, making colonization very fast indeed.
JP2: Barnard's Star. M4V primary. 5 Planets. Second planet has thin O-N atmosphere. Temp -66C.
JP3: Jump Point Three led to Lalande 21185. A red dwarf system (M2V primary) with ten planets and fifty-five moons, none of which were particularly appealing. Two planets and five moons had atmospheres - sparse in all but one case - but they were Nitrogen-methane, Helium - hydrogen and CO2 - Nitrogen Dioxide. The planets were all freezing and nothing was even close to habitable.
JP4: Proxima Centauri. M6-V. 6 planets. 300 asteroids. Second planet -63C. Thin but almost breathable ON atmosphere
JP5: Epsilon Eridani. K2-V. 9 planets, 75 moons. Planet II thin ON atmosphere +69C. Planet III thin ON -65C
JP6: Wolf 359. M6-V. 12 planets. 74 moons, 83 Ast. Planet I Thin ON Atmos. -73C
JP8: Ross 128. M4-V. 7 planets, 67 moons, 59 asteroids. Nothing close to habitable
Alpha Centauri has been surveyed and has five jump points
JP1: Ross 154. M3-V Primary. 7 planets,78 moons, 51 asteroids. Nothing close to habitable
JP2: Sirius: A1-V primary and white dwarf companion at 20 AU. Total of 10 planets (one of which orbited the companion) and 162 moons. Nothing habitable
JP3: YZ Ceti: M6-V. 7 planets, 43 moons, larger asteroid belt. Sparse ON atmos on YZ Ceti I but not close to breathable
JP4: Sol
JP5: WD 1142-645. A planetless white dwarf system.
Groombridge 34 has been surveyed and has four jump points. One leads to Sol and the other to YZ Ceti (which also connects to Alpha Centauri). The other two connect to:
Van Maanen's Star - a planetless white dwarf system
Stein 2051 - a binary with a white dwarf primary and an M4V red dwarf companion at 39 AU. Total of 11 planets, 126 moons, small asteroid belt. Nothing habitable.
***********
The most obvious difference from the normal system generation is the number of red dwarfs as in reality they are by far the most common star type. As you get further from Earth the proportion of red dwarfs will begin to fall a little, partly because they haven't been detected yet by Earth-bound astronomers and partly because I began skipping a few of the non-named ones (those that just have catalogue numbers). I think this will likely result in fewer ideal worlds but more worlds that could be terraformed but only extensive playtesting will really show what is going to happen. There are now 1000 stored systems in the DB, 60% of which are within 50 LY of Earth and 75% are within 100 LY. Most of the well known stars are actually further away so you probably won't encounter them until later in a campaign. Even so you might really meet the Ophiuchi at 70 Ophiuchi which is only 16.6 LY away. There are several stars within the constellation of Orion within the game such as the three brilliant stars that make up Orion's belt (Mintaka - presumably home of the Mintakans from the TNG episode 'Who Watches the Watcher, Alnilam and Alnitak) at 916 LY, 1341 LY and 817 LY respectively. The Rigellians can perhaps be found in the Rigel system at 773 LY
. The Vulcans are apparently from 40 Eridani which is at 16.5 LY, the battle with the Borg was at Wolf 359, which is a mere 7.8 LY, Beware of Khan on Alpha Ceti VI (for some reason called Ceti Alpha VI in the series) at 220 LY. Anyway, you get the idea. If a real star system has been mentioned in any well-known fiction, it is probably now in the Aurora DB. If you find one that isn't, let me know and I will add itSteve
Post by: welchbloke on September 29, 2009, 05:07:22 PM
Post by: Steve Walmsley on September 29, 2009, 08:00:53 PM
Quote from: "welchbloke"
Looking good Steve. What size are you planning to expand the stellar DB to?I'm not sure. 1000 systems is plenty for most campaigns so I there is no urgency to expand it. Even so, I will likely have the occasional session of adding more systems when I am bored with programming
Steve
Post by: welchbloke on September 29, 2009, 09:17:12 PM
Quote from: "Steve Walmsley"
Quote from: "welchbloke"Looking good Steve. What size are you planning to expand the stellar DB to?I'm not sure. 1000 systems is plenty for most campaigns so I there is no urgency to expand it. Even so, I will likely have the occasional session of adding more systems when I am bored with programming :)
Post by: Laurence on September 30, 2009, 12:20:32 PM
Quote from: "Steve Walmsley"
The Rigellians can perhaps be found in the Rigel system at 773 LY :twisted:
Post by: ShadoCat on September 30, 2009, 12:48:45 PM
Quote from: "Steve Walmsley"
I'm not sure. 1000 systems is plenty for most campaigns so I there is no urgency to expand it. Even so, I will likely have the occasional session of adding more systems when I am bored with programming
Just curious, what happens if you start a game with more than 1000 systems? Does it use the real systems first (assuming that you will hit local stars closer to home)?
Post by: SteveAlt on October 01, 2009, 06:59:34 PM
Quote from: "ShadoCat"
The games with real systems will be restricted to those available in the database and the number of systems in the game isn't used. Essentially the universe has been prerolled and all the systems have been given their system numbers and star types. When they are discovered, the planets are generated.Quote from: "Steve Walmsley"I'm not sure. 1000 systems is plenty for most campaigns so I there is no urgency to expand it. Even so, I will likely have the occasional session of adding more systems when I am bored with programming
Just curious, what happens if you start a game with more than 1000 systems? Does it use the real systems first (assuming that you will hit local stars closer to home)?
Steve
Post by: waresky on October 02, 2009, 05:07:46 AM
Quote from: "Laurence"
Quote from: "Steve Walmsley"The Rigellians can perhaps be found in the Rigel system at 773 LY :twisted:Damn cool for me:PP
Rigellians..Andromedans..Betelgeusans,,:))
and Vegans?:)
Post by: Steve Walmsley on October 04, 2009, 12:39:37 PM
Quote from: "welchbloke"
Quote from: "Steve Walmsley"A LOT! :), which has allowed me to spend a lot of time on Aurora. That is one of the reasons why Aurora has advanced a lot faster than SA. Another reason is that I am no longer trying to squeeze board game mechanics into a computer gameQuote from: "welchbloke"Looking good Steve. What size are you planning to expand the stellar DB to?I'm not sure. 1000 systems is plenty for most campaigns so I there is no urgency to expand it. Even so, I will likely have the occasional session of adding more systems when I am bored with programming :)
It definitely is several man-years though. Especially during the last 3-4 years when I have probably spent more time working on Aurora than most people will have spent at work.
Steve
Post by: Steve Walmsley on November 05, 2009, 01:33:29 PM
Steve
Post by: waresky on November 05, 2009, 01:43:28 PM
U have think how many Stars System atm (in a Quad Core IBM CPU) can manage an actual PC?
Post by: Steve Walmsley on November 05, 2009, 01:52:07 PM
Quote from: "waresky"
Awesome Steve..No idea
U have think how many Stars System atm (in a Quad Core IBM CPU) can manage an actual PC?
. A lot will depend on how many system bodies are in each system. I imagine you will run out of time to play before you run out of systems though.Steve
Post by: welchbloke on November 05, 2009, 01:56:59 PM
Quote from: "Steve Walmsley"
Quote from: "waresky"Awesome Steve..No idea :D
U have think how many Stars System atm (in a Quad Core IBM CPU) can manage an actual PC?
Post by: Randy on November 19, 2009, 12:38:36 PM
Too bad there is no real alternative other than sql server express edition. This would at least double the database size limit, but I believe it would introduce a whole host of other issues...
Post by: Theodidactus on December 02, 2011, 01:11:08 AM
Quote from: Steve Walmsley link=topic=1654. msg15253#msg15253 date=1252245772
If anyone has their own favourite stars (or has named one for their wife/girlfriend <img src="{SMILIES_PATH}/icon_smile. gif" alt=":)" title="Smile" />), let me know and I will include it in Aurora's DB.
Steve
Zubenelgenubi
Post by: Steve Walmsley on December 02, 2011, 01:36:54 PM
Zubenelgenubi
This binary system is already included as Alpha-1 Librae and Alpha-2 Librae. I'll change the names in the database to Zubenelgenubi-1 and Zubenelgenubi-2
Steve
Post by: Mel Vixen on December 03, 2011, 02:30:51 AM
Post by: Steve Walmsley on December 03, 2011, 02:49:17 PM
Steve now that Exoplanets get discovered almost dayly any plans of adding them to the appropriate stars? Also 1800 stars is a lot :P thanks for the effort.
I have considered adding exoplanets to real stars. The issue is that the system generation is so complex, it would be difficult to intervene in the correct place :). I will definitely look at this at some point though, as well as updating the Sol system to use the new dwarf planet definition and add Eris, Sedna, etc.
Steve
Post by: Zed 6 on December 03, 2011, 04:20:55 PM
As of February 2011, NASA's Kepler mission had identified 1,235 unconfirmed planetary candidates associated with 997 host stars, based on the first four months of data from the space-based telescope, including 54 that may be in the habitable zone.
Most known exoplanets orbit stars roughly similar to our own Sun, that is, main-sequence stars of spectral categories F, G, or K. One reason is that planet search programs have tended to concentrate on such stars. But in addition, statistical analysis indicates that lower-mass stars (red dwarfs, of spectral category M) are less likely to have planets massive enough to detect. Observations using the Spitzer Space Telescope indicate that stars of spectral category O, which are much hotter than our Sun, produce a photo-evaporation effect that inhibits planetary formation.
Ordinary stars are composed mainly of the light elements hydrogen and helium. They also contain a small proportion of heavier elements such as iron, and this fraction is referred to as a star's metallicity. Stars of higher metallicity are much more likely to have planets, and the planets they have tend to be more massive than those of lower-metallicity stars. It has also been shown that stars with planets are more likely to be deficient in lithium
Post by: Beersatron on December 03, 2011, 05:04:22 PM
..............
A system has been discovered in which a planet orbits around two suns, which orbit around each other.
..............
Link?
Post by: Owen Quillion on December 03, 2011, 06:42:30 PM
Here's the Wikipedia page on the system (http://en.wikipedia.org/wiki/Kepler-16)
Here's a Wikipedia also a Wikipedia page that says there are several older confirmed ones (http://en.wikipedia.org/wiki/Circumbinary_planet), presumably by methods other than transiting.
Here's an article from Sky & Telescope (http://www.skyandtelescope.com/community/skyblog/newsblog/129909203.html) about the Kepler-16 planet.
I remember reading about this back in September and getting pretty excited; it's not exactly Tatooine or anything, but still pretty neat. (it's Saturn-esque, if I remember correctly)
Post by: TheDeadlyShoe on December 03, 2011, 07:53:31 PM
Quote
I have considered adding exoplanets to real stars. The issue is that the system generation is so complex, it would be difficult to intervene in the correct place . I will definitely look at this at some point though, as well as updating the Sol system to use the new dwarf planet definition and add Eris, Sedna, etc.Ceres? :X
Steve
Post by: Mel Vixen on December 03, 2011, 11:27:36 PM
For sol exist 5 dwarfplanets namely: Pluto, Ceres, Eris (1 Moon) which was formaly know as Xena, Haumea(2 moons) and Makemake. Furthermore exist 4 ""nearly certain" dwarf planets which are Orcus (1 moon), Quaoar(1 moon), 2007 OR10 (nicknamed at first "Snow white" later 7th Dwarf because its a actually rather red) and Sedna.