Inner Moons List

Gromsch · Feb 25, 2019

Eol Prou QB-O c6-127 A B C D

1. new shepherd moons
system: Eol Prou QB-O c6-127 / ~320ly from Colonia
parent body: Eol Prou QB-O c6-127 6 / class I gas giant / 2 rings
shepherd moons: Eol Prou QB-O c6-127 6 A, B, C & D / all in the same quite large gap of the two rings
image:

2. you're welcome & thank you

Shnyrik said:
Thank you!

Very nice infographics, by the way!

I thought it was worth the time since this toppic

made me appreciate ringed gas giants again (I was experiencing a severe case of "exploration dullness" in the last weeks)
is not about GGGs, which I think are a myth and all evidence is photoshopped (I have not come across one of those)
is not about codex entries^{[SIZE=1]*[/SIZE]} and purely community driven [up]

I'm sorry that the new graphic is a bit cluttered. Four shepherd moons are a blessing and a curse [big grin] .
I hope there are not too many typos.

3. fictional nonsense
The the shepherd moons around Eol Prou QB-O c6-127 6 have already been (inofficially) named by me (who else?).

Eol Prou QB-O c6-127 6 A -> "Marble Halls"
Eol Prou QB-O c6-127 6 B -> "Book of Days"
Eol Prou QB-O c6-127 6 C -> "How Can I Keep From Singing"
Eol Prou QB-O c6-127 6 D -> "Caribbean Blue"

Those are the four singles releases of the ablum "Shepherd Moons" by Enya**.
When searching the internet for "shepherd moons" one of the hits brought me to the wikipedia page of mentioned studio album.
Four shepherd moons, four single releases from an album called "Shepherd Moons", plus the fact that ring B reminded me of a good old vinyl record. That made naming the moons pretty easy.

* I've got my share of codex (first discovery) entries. But in hindsight I think I should change my CMDR's name to CaptPlanetFart. You will find my name next to fumaroles, geysers, gas vents, ... not very satisfying.
** This shall not reflect my taste in music.

Gromsch · Feb 28, 2019

Eol Prou XJ-Q d5-1268 4 A B C & D

system: Eol Prou XJ-Q d5-1268
parent body: Eol Prou XJ-Q d5-1268 4 / class I gas giant / 2 rings
shepherd moons: Eol Prou XJ-Q d5-1268 4 A B C D
note: 2nd ring is not visible in space, but can be found in the system map and orrery.
image: (less text, more fly-by shots)

Shnyrik · Feb 28, 2019

And one more gas giant with shepherd moons: Dryaa Pruae BG-X d1-5664 body #12.

When viewed from cockpit, this gas giant is completely unremarkable.

However orrery view shows, that it has very large sparse outer ring around it's two innermost moons.

Orvidius · Feb 28, 2019

Yeah, moons inside rings are actually pretty common. I think my spreadsheet reports are showing over 688k of them from the EDSM data.

Shnyrik · Mar 1, 2019

Orvidius said:
I think my spreadsheet reports are showing over 688k of them from the EDSM data.

Well, that's really quite a lot.

The list alone weights over 100 Mb.
https://edastro.com/mapcharts/files/shepherd-moons.csv

To be honest, having found one system with shepherd moons myself and some more with the help of reports from other commanders, I just couldn't imagine there were so many systems already scanned to EDSM.

Qohen Leth · Mar 1, 2019

Last night I found one GG with 5 shepherd moons, 2 single ones and 3 in a super-close binary + one configuration. Will have to fetch the system name.

Gromsch · Mar 1, 2019

Orvidius said:
[...] moons inside rings are actually pretty common. [...]

One thing that surprised me in my ~2 week hunt for shepherd moons is that I actually found some. Considering my overall "luck" in exploration shepherd moons do seem common.

But here comes the "but" ...

I found that alot of the cleared (outer) rings are not visible from space. The only indication that they are there is in the system map and the orrery (and with some effort I could sometimes probe them, but they were still not highlighted in "analytic space view").

I have found only one case where both rings and the moons are visible. Something that is definitely not visible in a textfile^{[COLOR=#ff8c00]*[/COLOR]}

.

Shnyrik said:
[...] The list alone weights over 100 Mb. [...] I just couldn't imagine there were so many systems already scanned to EDSM.

For me it is about the aesthetics and maybe to show some nice examples of shepherd moons to interested CMDRs.
So, unless CMDR Shnyrik decides to call off the hunt, I will still post my findings here and limit the posts to shepherd moons within visible rings^{[COLOR=#00ff00]**[/COLOR]}.

* If filters are applied (limit the outer ring's radius !?), there might a chance to guess which bodies have visible enclosing rings.
** Again, considering my overall "luck" in exploration, this might be my last post in this topic [big grin]

Orvidius · Mar 1, 2019

Gromsch said:
But here comes the "but" ...

I found that alot of the cleared (outer) rings are not visible from space. The only indication that they are there is in the system map and the orrery (and with some effort I could sometimes probe them, but they were still not highlighted in "analytic space view").

... And that's a really great point. I don't think in the data there's a way to separate out those rings, so the spreadsheet may be overflowing with cases that are "true" in the data, but not apparent in-game. I wonder if there's a cutoff in terms of the ring's mass, or mass:radius ratio.

The mass range is quite huge. Looking at all rings in the database, the lowest ones are single-digits (with three that have zero mass, and two more without a mass number), but the heaviest ring's mass is 198,520,000,000,000,000

EDIT: Caveat on that one, it's a belt around a star, treated as a ring. The heaviest one I see for a planet is 4,673,500,000,000,000.

Gromsch · Mar 2, 2019

Orvidius said:
[...] I wonder if there's a cutoff in terms of the ring's mass, or mass:radius ratio.[...]

Me too.

So, I gathered the information in this thead (visibility in screenshots, comments, EDSM links, etc. ) and found ... nothing [blah] .

I don't see any correlation. Then again, the data set is quite small and maybe I'm looking at the wrong parameters.

Sidenote:
Yesterday I excluded the graphic settings as a cause on my side. I came by one of those "invisibles" and tested various detail settings. I also looked at the ring from different angles and with different backgrounds (galactic center, out into the void), I did not see no nothing

.

EDIT: Note: There is an error in data point 6 (invisible). Y value should be around 11.8.

Shnyrik · Mar 2, 2019

Gromsch said:
Yesterday I excluded the graphic settings as a cause on my side. I came by one of those "invisibles" and tested various detail settings. I also looked at the ring from different angles and with different backgrounds (galactic center, out into the void), I did not see no nothing .

Graphic settings have nothing to do with invisible rings, for you can actually fly through them (at least some of them) in SC and meet no obstacle. Tried it in Phroea Hype CM-C d24 many times before I've found explanation by QA-Jack, that it is actually considered normal

https://forums.frontier.co.uk/showthread.php?p=7098730&viewfull=1#post7098730

Gromsch said:
So, unless CMDR Shnyrik decides to call off the hunt, I will still post my findings here and limit the posts to shepherd moons within visible rings

Well, I think that extending the list in the OP to 680k systems may be a bit too much

Especially now, when we have full list extracted from EDSM. However we may get some more statistic and define some less common type of shepherd moons and collect them

The idea with visible and invisible rings, actually, seems pretty reasonable.

I think, we may continue the list as it is for some time, and a bit later after CG at WP7 (especially if there finally would be shipyard and I would be able to order my long range DBX) I'll study the full list, make a list of nearby systems with shepherd moons, and check them all, so that we could get some statistics to decide what to do later.

Orvidius · Mar 2, 2019

Gromsch said:
So, I gathered the information in this thead (visibility in screenshots, comments, EDSM links, etc. ) and found ... nothing [blah] .

I don't see any correlation. Then again, the data set is quite small and maybe I'm looking at the wrong parameters.

Thanks for trying! I was hoping there would be a clear "rule" that was in play, that we could filter against. No such luck, I suppose.

EDIT: What I might do, is change the purpose of the spreadsheet I generated. I might make it a requirement that the moons orbit inside one of the inner rings, and leave out the outermost ring. Not ideal, but the spreadsheet is pretty useless with almost 700k entries.

Gromsch · Mar 2, 2019

Shnyrik said:
[...] you can actually fly through them (at least some of them) in SC and meet no obstacle. Tried it in Phroea Hype CM-C d24 many times before I've found explanation by QA-Jack, that it is actually considered normal [...]

The funny thing is: Sometimes the invisible rings are 'probe'ble. Not by a ballistic shot, but by shooting straight at them. I usually target the main body, fly in a position where a shepherd moon (foreground) and the main body (background) are in a straight line, do a 180 to have the main body behind me, use a km-to-ly converter and, when I'm at a distance to the main body where the ring should start (inner radius), I switch to DSS and 'ring' pops up right in front of me. This, of course, only works if the ring is not too far from the main body and main body, moon and ring are in-plane.

Shnyrik said:
[...] The idea with visible and invisible rings, actually, seems pretty reasonable.[...]

Orvidius said:
[...]I was hoping there would be a clear "rule" that was in play, that we could filter against. No such luck, I suppose.[...]

This may sound mean, but I'm actually happy about this. It means we have to explore the galaxy in-game and not in a spreadsheet

.

Orvidius · Mar 2, 2019

Gromsch said:
This may sound mean, but I'm actually happy about this. It means we have to explore the galaxy in-game and not in a spreadsheet .

I totally get what you mean, no worries.

I think it's great that there are some questions we can answer quite well from the data, and others that we can't. The mix keeps it interesting.

I've updated the spreadsheet to ignore the outermost ring, so it also ignores planets with only one ring. This cut the list in half, down to 350k entries. I'm not sure it's all that useful of a spreadsheet, so I may remove it at some point, and write it off as an interesting experiment.

Gromsch · Mar 3, 2019

I did what every good scientist does: I tortured the data till it surrendered!

remark: ρ = m/( π (r²[SUB]outer[/SUB] - r²[SUB]inner[/SUB]))

The numbers in the plots correspond to the following bodies:

Dryaa Pruae BG-X d1-5664 12
Eol Prou VD-J d9-113 A 8
Phroea Hype CM-C d24 8
Eol Prou XJ-Q d5-1268 A 4
Dryooe Prou ZS-S b4-17 4
Eorm Phyloi DU-A d431 B 5
Hypoe Prau TF-O b51-21 4
2MASS J18190744-1640266 6
Eol Prou QS-T d3-233 ABC 1
Prooe Drye FH-J d10-68 6
Schee Phio AW-C d82 11
Splierd UD-B d1 8
Wepae AA-A h22 ABC 1
Byoi Eurk LM-W e1-10 6
NGC 7822 Sector BQ-Y d12 A 3
Eol Prou GC-L d8-16 AB 1
LTT 16019 3
Ooscs Freau ZY-S d3-1486 B 2
Pha Euhn WS-U d2-0 2
Eol Prou QB-O c6-127 A 6
Sphaukee OB-X d1-3 B 4
Myriesly BA-F c25-5957 3
Myriesly EC-B c27-4778 5
Myriesly FC-B c27-2972 6
Myriesly FM-L c21-6944 3
Myriesly GQ-G d10-8313 5
Myriesly IB-D c26-4138 4
Myriesly ID-I c23-1068 2
Myriesly IZ-I c9-2760 B 10
Myriesly LC-D d12-5390 3
Myriesly LC-D d12-7691 BC 2
Myriesly MY-Z c13-1205 5
Myriesly MX-A c27-7103 5
Myriesly NF-B c15-22 3
Myriesly NH-K c22-709 A 1
Myriesly QR-K c9-4422 B 10
Myriesly RD-Z c27-7159 6
Myriesly UJ-X c28-4075 4
Myriesly XJ-I d9-8271 8
Myriesly XT-G c24-199 B 3
Myriesly YE-G c24-6222 5
Myriesly ZJ-P c19-7678 3
Myriesly ZJ-R c4-861 8
Myriesly ZK-N d7-1528 5
Myriesly ZK-N d7-8615 1
Sphaukee OB-X d1-3 B 4
Phraa Prao HA-C c2-37 7
Phipue MA-X b15-21 7
Dryaea Chraei NR-W d1-87 7
Dryooe Blou XQ-K d9-44 B 7
Dryooe Blou XQ-K d9-48 A 5
Sphauloea FI-J d9-11 11

Conclusions:

Invisible rings are most likely icy^*.
There seems to be a line (top left to bottom right) that devides the visible and non visible rings in both plots.
There still is an area of uncertainty around that line.
My guess is, the visibility of rings close to that line depends on the distance of their parent body to the central star and the bightness of the central star^**.
We need more data [big grin].

* I had to remove one invisible ring from my data set. There was only a screenshot of the orrery map for that ring and I assumed it to be invisible. My fault.

** This would mean the in-game lightning model also controls the physical interaction as some invisible rings can be just flown through.
This "If you can't see me, I can't hurt you" bahavoiour is not unheared of (see Ravenous Bugblatter Beast of Traal).

Edit(1): I updated the image. There was an error in data point 5 (Dryooe Prou ZS-S b4-17 4), thx MattG for pointing that out.
Edit(2): more data added

Orvidius · Mar 3, 2019

Hey, that's pretty cool! That uncertainty range might indeed be getting influenced by the orbit of the planet around the star. If the ring extends beyond the planet's sphere of influence, for instance, it technically shouldn't exist, so they may hide it.

MattG · Mar 4, 2019

Gromsch said:
I did what every good scientist does: I tortured the data till it surrendered!

Do you have a table of the data for the rings at all? I checked EDSM but a good handful don't seem to be there...

Orvidius · Mar 4, 2019

After a couple of private messages and investigating further, I've decided to just take down the spreadsheet I was generating. It's too unreliable. There are a lot of moons that are missing their orbital information (creating a lot of false negatives), and many false-positives due to binary pairs of moons storing the orbital data for their orbits around each other, rather than around the parent. And this doesn't even begin to address the issue with invisible rings either.

Sorry for going down a rabbit hole with a dead-end. Carry on!

Gromsch · Mar 4, 2019

MattG said:
Do you have a table of the data for the rings at all? I checked EDSM but a good handful don't seem to be there...

You are correct, it is exactly a handful of bodies/rings [big grin]. I found five shepherd moon occurrences while exploring and those values come from system maps/my screenshots. I used the EDSM API for the remaining 15.
I'm a little lazy (and slightly annoyed of copy-pasting information into a forum table

), therefore I'm just gonna post my octave/matlab variables.

The values in 'rings' are the triplet for the outer most ring of the body [inner radius, outer radius, mass]
'visibility' is eyeballed from the screenshots; 0 - not visible, 1 - visible.
'type' : 1 - Icy, 2 - Rocky, 3 - Metal Rich

Code:

names = ["Dryaa Pruae BG-X d1-5664 12",
"Eol Prou VD-J d9-113 A 8",
"Phroea Hype CM-C d24 8",
"Eol Prou XJ-Q d5-1268 A 4",
"Dryooe Prou ZS-S b4-17 4",
"Eorm Phyloi DU-A d431 B 5",
"Hypoe Prau TF-O b51-21 4", 
"2MASS J18190744-1640266 6",
"Eol Prou QS-T d3-233 ABC 1",
"Prooe Drye FH-J d10-68 6",
"Schee Phio AW-C d82 11",
"Splierd UD-B d1 8",
"Wepae AA-A h22 ABC 1",
"Byoi Eurk LM-W e1-10 6",
"NGC 7822 Sector BQ-Y d12 A 3",
"Eol Prou GC-L d8-16 AB 1",
"LTT 16019 3",
"Ooscs Freau ZY-S d3-1486 B 2",
"Pha Euhn WS-U d2-0 2",
"Eol Prou QB-O c6-127 A 6",
"Sphaukee OB-X d1-3 B 4",
"Myriesly BA-F c25-5957 3",
"Myriesly EC-B c27-4778 5",
"Myriesly FC-B c27-2972 6",
"Myriesly FM-L c21-6944 3",
"Myriesly GQ-G d10-8313 5",
"Myriesly IB-D c26-4138 4",
"Myriesly ID-I c23-1068 2",
"Myriesly IZ-I c9-2760 B 10",
"Myriesly LC-D d12-5390 3",
"Myriesly LC-D d12-7691 BC 2",
"Myriesly MY-Z c13-1205 5",
"Myriesly MX-A c27-7103 5",
"Myriesly NF-B c15-22 3",
"Myriesly NH-K c22-709 A 1",
"Myriesly QR-K c9-4422 B 10",
"Myriesly RD-Z c27-7159 6",
"Myriesly UJ-X c28-4075 4",
"Myriesly XJ-I d9-8271 8",
"Myriesly XT-G c24-199 B 3",
"Myriesly YE-G c24-6222 5",
"Myriesly ZJ-P c19-7678 3",
"Myriesly ZJ-R c4-861 8",
"Myriesly ZK-N d7-1528 5",
"Myriesly ZK-N d7-8615 1",
"Sphaukee OB-X d1-3 B 4",
"Phraa Prao HA-C c2-37 7",
"Phipue MA-X b15-21 7",
"Dryaea Chraei NR-W d1-87 7",
"Dryooe Blou XQ-K d9-44 B 7",
"Dryooe Blou XQ-K d9-48 A 5",
"Sphauloea FI-J d9-11 11"];

rings = [
[1164900    11741000    603130000000],
[691250    11060000    10468000000000],
[2202300    8777500    6367400000000],
[1211782    4847127    1468503556096],
[518538    3189924    600512135168],
[474786    2971770    82842927104],
[695143    1747092    4393857024],
[4349100    27615000    287310000000000],
[15753000    25006000    143620000000000],
[1062400    4249600    4962300000000],
[6913900    17422000    89779000000000],
[1260200    5040900    4220300000000],
[27463000    43595000    758580000000000],
[4471500    11197000    448750000000000],
[715770    4544800    9476600000000],
[1071100    1700200    40211000000],
[616950    979350    118540000000],
[992210    1575000    47867000000],
[732750    1163200    9806100000],
[1271106    2017755    249402179584],
[1698660 4280355 940220284928],
[627503 996029 3001711104],
[1969202 3125913 2643175931],
[1495416 2370364 1688001445888],
[525632 1324500 1289315549184],
[283498 7291157 2311422214144],
[580540 2322100 9780600000],
[434084 1736335 19258992640],
[1828066 2891913 39869419520],
[498840 1257000 6943700000],
[1932929 3068333 52292050944],
[1507239 2384362 8179911168],
[675948 4292005 8995760128],
[1030444 4082603 36994449408],
[1109024 2794566 47449018368],
[1028584 2591870 46364966912],
[1421800 5687100 175460000000],
[1586928 2998808 190036918272],
[1249496 12594133 7698696372244],
[1551923 2463524 522662150144],
[563726  2254905 156945563648],
[4050193 6429280 2911651758080],
[801630 2002000 3717700000],
[750860 3003500 1354300000],
[1300278 2064063 341424209920],
[1698660 4280355 940220284928],
[1062205 4248819 20064845824],
[2566834 4074595 1445378654208],
[2190357 22077412 800344440832],
[1514175 3815482 222112448512],
[1895905 7583622 19362600960],
[4310721 7319063 2340862820352]];

visibility=[0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,0,0,0,0,1,0,1,0,0,0,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0];

type=[1,1,1,1,1,1,1,3,3,1,2,1,3,2,1,2,1,3,2,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,3,3,1,1,1,2,1,3,1];

Orvidius said:
[...] Carry on!

I will!

Edit(1): Corrected the mass for Dryooe Prou ZS-S b4-17 4, thx MattG for pointing that out.
Edit(2): more data

Shnyrik · Mar 4, 2019

Orvidius said:
and many false-positives due to binary pairs of moons storing the orbital data for their orbits around each other, rather than around the parent

Yep. I was just going to report that

I've finally managed to catch up with the expedition and (while CG has not yet started) I'm now checking moons in Myriesly sector. And for now all of them were those false-positive binary moons.

However, I'm not ready to give up your list completely just yet

I have an idea of how to sort the majority of false-positive results out. Your list counts all moons inside rings one by one, not just systems they are in. And that gives a possibility: if moons listed in one system start not from #a -- those are for sure binaries, for you just can't have #d and #f inside ring, while #a is not. The decision is simple then: as I need only system names to check, I just need to sort out all the lines, where moons are not #a.

So I've extracted 594 entries from the table about moons in Myriesly sector and now narrowed the list down to only 54 systems. Will try to check them on EDSM and at least some of them, that would seem the most promising, "manually" tomorrow evening.

Orvidius said:
Carry on!

I definitely will

Orvidius · Mar 4, 2019

Gromsch made a suggestion to limit the spreadsheet to shepherd moons specifically, meaning that their orbits fall between rings, and not between the planet and the first ring. This creates false negatives out of any binary pairs that are inside the ring systems, since it effectively filters out all such pairs. But there's a higher degree of certainty in the remaining moons.

It still has the caveat that it leaves out any moons that don't have adequate orbital data in the data set (for whatever reasons).

Here's the file:

https://edastro.com/mapcharts/files/shepherd-moons.csv

At the moment it's 35,305 entries, and about 5 MB.