Jackie's Hab-Zone Calculator

[Jane Turner]

No, that's a good point - I hadn't anticipated using it on Neutron stars. I've uploaded a new build which assumes that a value of 0 for radius implies a Neutron star.

Obviously I haven't yet checked this against Neutron stars in the game.

Fabulous - thanks

 

[Jackie Silver]

what info do you need on neutron stars, I'm 25,000 LY out and have been scanning neutrons for the quick credits. Off the cuff I can tell you that there are terraform worlds at approx ~1200Ls-~1800Ls from the neutron star. As I have found a few when they look earth-like.

The temperature of the neutron stars in the game varies widely and it's that which determines their habitable zones as they should all have a similar radius. I'm assuming a value of 12km for their radius in the program. I need to find out whether that is accurate, or if it is a slightly different figure, or whether there's a (hidden, as they all show radius "0") variation between different neutron star radii.

If you're really keen and you happen to find a neutron star that's by itself and has planets around it, you could look for high-metal-content or rocky planets without atmosphere, put the star's parameters into the tool and then put the semi-major-axis distance of the planet into the tool on the second page - the final report will show a "general" temperature for that distance somewhere near the bottom. If that value is reasonably close to the "real" temperature of the planet that the game shows when you scan it, then everything is working well, if not there's a problem. In either case I'd be interested to know how it turns out.
(Alternatively, if you find an airless iceball, see if its temperature is similar to the "iceball" temperature. I don't think I've got the albedo exactly right for iceballs and riceballs, but it's close enough for the moment.)

 

[J. diGriz]

I collected some preliminary Neutron star data.. all from single neutron stars. It was easier to just record the info rather than plug it into the calculator. For the next batch I'll collect the approx distance in LS from the neutron as there are quite a few with a semi-major or is it semi minor axis of .01 AU.

	Neutron	G-3	G-2	RI-moon	HM
size/semi-major axis	0.8086	2.79 AU	3.65 AU		4.99 AI
temp	2,393,045K	344K	233K	190 K	179 K
	Neutron	HM(T)	HM(T)	EL
size/semi-major axis	0.75	.01 AU	.01AU	7.21 AU
temp	2,393,045 K	671 K	397 K	272 K
	Neutron	G-3	RW-moon	RW-moon
size/semi-major axis	0.7344	2.51 AU
temp	3,691,786 K	467 K	410 K	411 k
	Neutron	HM	HM	HM	HM	HM
size/semi-major axis	0.6992	.01 AU	.01 AU	4.48 AU	5.54 AU	8.07 AU
temp	8,732,756 K	846 K	846 K	903K	1,724 K	1,719 K

 

[Andargor]

If you are looking for extremes, then the records thread can help you.

 

[Jackie Silver]

I collected some preliminary Neutron star data.. all from single neutron stars.

Cheers - can you get me the mass of the gas giants also, and the atmosphere composition and pressure of the terrestrials please? You're right about the close-orbiting planets, I've been having to get their distances in ls.

If you are looking for extremes, then the records thread can help you.

*grins* Thanks, but it's only to an extent. I need a bunch of other conditions met which the record-holders don't necessarily had.


The current test version can just about handle limited multiple-star systems; the example below is for the STF 1774 system looking at the smaller star; the predicted temperatures of the airless rocks orbiting STF 1774B match to within ten degrees or so.
More work needed!

 

[Wolfman]

Jackie, magnificent work. Thank you.

 

[Jackie Silver]

I think I've worked out how the game handles multiple star systems (turns out I was seriously overthinking it, the game appears to be taking a shortcut); should probably get a build up this weekend.
Also in practice the utility of predictions involving multiple stars is limited by needing to have their temperatures - you have to go to the trouble of flying to all the stars...

Also: Ambivalent, you were right about that system with the too-distant water world. The contributions from the other stars in the system shouldn't have been high enough - but they are.

(eta)
Ugh. I'm failing here.

 

[Jackie Silver]

Ambivalent, here's a bmp to jpg converter, point it at your screenshot directory.

I'm still having real trouble with the multiple star systems; thought I had it worked out but each time something happens to confuse me. It's proving difficult to test. Sorry folks.

 

[Jackie Silver]

New Release!

Finally, here's a new version that can handle multiple-star systems to some extent.
The zones for water worlds and ammonia worlds are also much more accurate than previously.
In particular, the ammonia world zone extends to much colder temperatures now.

Thanks to everyone who's helped with planet data, particularly Reido and Ambivalent.

Planet data spreadsheet and program source code are inside the .zip archive.

Download link to version 0.25

So, how do I use this thing?

If you're looking at a single star system only, things haven't changed much.
When you run the program, you have the chance to enter values for primary stars:
(the default radius and temperature are for Sol)



Ignore the panel for secondary stars, just leave it all blank:



If you're interested in checking the temperature at a particular distance, you can put values in the next panel, otherwise leave it alone also:



Now you'll get an image of the system showing the main habitable zone (green), water world zone (blue) and ammonia world zone (red).
Also shown are the 100% metal world zone (grey), a background showing very roughly the split between high metal content (brown) and ice / rocky/ice (white) worlds, and a couple of lines showing where CI and CII gas giants can be found.
Values above the bar are the start of the zone in aus from the primary star, values below are the end of the zone.



Finally you get a summary showing the results:



If you want to use a Neutron Star, put NS into the radius box, and if you want to use a White Dwarf, put WD into the radius box.

Using it on multiple star systems is considerably more complicated, so I'll write that up in a following post.

 

[Jackie Silver]

Using the tool on multiple-star systems.

This is still experimental and may struggle with more complicated systems, but it certainly works for an example like the one I'll follow here.
The imgur link shows details for the system of IC 1396 Sector VN-R C5-1:

http://imgur.com/a/55vOX

We're going to find the temperatures of the first three rocky planets that are orbiting the binary pair.

For the purposes of the program, the two stars in the binary pair are "primary" stars - those planets are directly orbiting them.
(In the calculation, the distance to these stars is considered to vary.)

The star which is at a greater distance is a "secondary" star - the planets are not directly orbiting it.
(In the calculation, the distance to this star is not considered to vary.)
We need to find the distance between this star and the primaries, and the game doesn't give it directly, so have to measure it from inside the game.
The distance is roughly 4520 light seconds, which is 9.06 au.

Put the values for primary stars in:



And for the secondary star:
(Note that there is a third field for each star on this page, for distance, in this case 9.06 au)



I put the distances for those planets into the next box:



And get the zone display screen:
(Note that this is truncated compared to the usual result, because of the secondary star it doesn't make sense to give distance values far out from the primaries.)



And the results:



The program guessed 416K, 348K and 307K for the planets (they're high metal content, so of "general" type - anything except iceballs and riceballs is "general", albedo 0.35) at 0.27, 0.4 and 0.53 au respectively.
From the imgur album the "real" values are 415K, 349K and 307K, which is accurate enough for most purposes.

 

[Jackie Silver]

So, why'd it take you so long?

When working out the temperature of an object (the planet) which is being lit from several different sources (the stars) the correct calculation involves working with the sums of the energy inputs together.
It doesn't work by finding out the temperature rise from one source, then from another source, then adding them together.

I tried the first approach; it didn't work.
I tried the second approach just in case; it didn't work.

What Dangerous does, for reasons beyond me, is to use a combination of both methods: as far as I can tell the primaries are done "properly", and the secondaries are done "properly", but then the temperature increase from primaries and secondaries are summed to get the final temperature.
(The upshot is that planets are considerably hotter than they should be in multiple-star systems.)

So, anyway, it took me a while to work out what was going on, hence the delay. I also made a lot of mistakes and even spent some time playing the darn game.

Spoiler

 

[Ambivalent]

Awesome stuff Jacike, I'll be putting this to the test soon.

I found a strange WW CFT last night though which broke the basic hab zone calc - here are the stats -

Planet

Spoiler

Star

Spoiler

Calc Result - http://i.imgur.com/8zh3lY3.png

So it fell 0.2 AU beyond what the tool said it would, grrrr.

 

[Jackie Silver]

Awesome stuff Jacike, I'll be putting this to the test soon.

I found a strange WW CFT last night though which broke the basic hab zone calc - here are the stats -

Planet

Spoiler

View attachment 26156

Star

Spoiler

View attachment 26157

Calc Result - http://i.imgur.com/8zh3lY3.png

So it fell 0.2 AU beyond what the tool said it would, grrrr.

Interesting - I've been treating the main habitable zone as a single unit within which all HMC and WW or suitable mass can be CFT and outside of which they can't, but perhaps the WW bit extends cold-wards a little further.

 

[Andargor]

Smart meerkat is smart.

 

[Jackie Silver]

Quick update - I finally got round to testing on Linux and noticed that the file system references were broken (as Windows uses '\\' and Linux '/', and I've only been using simple strings to refer to files); I've uploaded a modified version that runs properly on Linux.
The program depends on easygui for Python 3 and pillow for Python 3 so install both of those first (e.g. from Ubuntu's software centre it's a couple of mouse clicks, simples!); it also needs the font file that's in the folder with the source code.

 

[Ben Ryder]

Gosh this looks clever. Whats it do?

 

[Jackie Silver]

Just a quick note here: the values for zone ranges for Ammonia worlds and Metal-Rich worlds are (as expected) a bit larger than the ones in the currently uploaded builds of the calculator. We're doing a big survey of worlds over in the Exploration forum at the moment and once more data is in I'll update the builds to new versions that include the bigger ranges.

 

[wolverine2710]

In the past your excellent tool, thread has been added to EDCodex. Before EDCodex was released on the 17th of August you have received in the period 5th - 10th of August a PM with an invitation and a special link. After registering and logging in you would automatically become owner of your entry. According to the admin tool(s) you haven't used the special link (yet). Perhaps you have missed the PM or have been (temporarily) away from ED. Its also possible you choose not to claim your entry. Note: Its also possible to assign another commander editing rights for your entry. In either case please send us a PM. You can find your EDCodex entry here.

Alternative way to get ownership
The special link will cease to function in the (near) future, for security reasons. Should you after that point want to become owner of your entry you can use the "Claim ownership" button. In that case please send biobob or myself a PM with the email addressed you used for registration - for verification. You can also use this procedure if you no longer have the PM.

What is EDCodex:
Its a website with a database of currently approx 215+ tools,threads,websites,videos for ED. Any one can and is encouraged to add entries there. EDCodex is and should be community-driven. EDCodex companion thread. Its equally suited for PC's, tablets and smartphones and has RSS feeds.

With kind regards,
Biobob
Wolverine2710

 

[Acen ONYX]

Dear Cmdr JS,

I'm .. dumbfounded. Wow.
Are you an avid astronomer IRL too? And/or seeerious mathematician?? And/or uuuber programmer?!? '
That's some pretty amazing stuff you're producing..!!

At this rate, you'll be finding REAL aliens in our REAL galaxy before too long.....

 

[Acen ONYX]

..and my first +Rep as a Reg'd forumite goes to you, Jackie Silver.