When looking through the old forum, I noticed a large surge of threads regarding object extremes. Whether it'd be Largest Planet to Largest Star, or regarding the highest ESI, we can all agree that those threads were very popular. Instead of just having scattered "extremes" threads, I decided it would be a good idea to condense them into one large thread. 

How it works
Below are a list of object extremes in Space Engine, ranked in to their respective classes, which are stars, planets, and systems. They will regard: Mass, Temperature, Size, Gravity, Luminosity, Systems, and future categories. The objects can be procedural or real, however no user created systems or objects can be used in the listings. If there is a user created system in the extremes lists, it will be promptly removed.
                                                                                 EXTREMES LIST:
PLANETS + DWARF PLANETS:

Largest: 

Smallest:

Most Massive:

Least Massive:

Most Moons:

Highest ESI:

Lowest ESI:

Coldest:

Hottest:

Densest:

Highest Albedo:

Lowest Albedo:

Largest Moon:

Most Host Stars:

Shortest Day:

Longest Day: Fomalhaut b

Shortest Year:

Longest Year:

Most Eccentric Orbit:

Least Eccentric Orbit: PSR B1257+12 A


STARS:

Largest: 

Smallest:

Most Massive:

Least Massive:

Densest:

Most planets:

Brightest:

Darkest: RS 5318-4-7-897554-4393 Luminosity: 4.0512x10^-10

Longest Rotation:

Shortest Rotation: PSR B1257+12

Hottest:

Coldest:

SYSTEMS:

Largest System Diameter:

Smallest System Diameter:

Most objects in a system: IC1101 Stellar Center

Least objects in a system:

Most Planets:

Most Stars:

Most Moons:

Most Objects Overall:

System With Most Extremes:




Good luck, and happy hunting!

Here's the problem; most people have modded games. The procedural objects are cataloged differently based on which mods you have. I guess what I'm asking is, does it have to be verifiable?

In order to validate, I will search the object candidate on my un-modded 0.9.8.0 server. if it's there, I will add the object to the list.

Darkest star:
RS 5318-4-7-897554-4393
Luminosity: 4.0512x10 [sup]-10[/sup] (This one should be there for everyone because it is in an elliptical galaxy)

Just to give the categories some stuff, here's a few
Star with shortest rotation: Lich
Star System with most stars: RSC 10396-10378-0-0-0 (IC 1101 central black hole)
Planet with the longest year: Dagon (Fomalhaut b)
Planet with lowest eccentricity: Draugr (can't be beat! 0 eccentricity!)

RS 5318-4-7-897554-4393

That is very dark, indeed.
If I remember correctly, yesterday I've found a very small star, I might post it here this evening.

Systems of a supermassive black holes should be considered in a separate category: "supermassive black hole system with most stars". Because they always will beat a normal star systems. Procedural normal star systems have only up to 8 stars, but cataloged one can have any number of stars.

hmm my superscript is [sup]not working[/sup] in my post of the darkest star, I can read the [sup] tag

I went searching for large stars and found this one at the Andromeda galaxy: (RS 1228-3177-0-0-240)

It's 138.77 AU across!

You put the IC 1101 system under the wrong category. Should be under "Most Stars" not "Most Objects"

Planet with most moons:
"RSC 0-9-88682393-225-0-2-28-1 A9"
Moons: 261

I have found a star that trump's Hornblower's darkest star:
RS 1228-3273-8-3661533-863
Luminosity: 3.2363e-10

Also, I found an extremely bright star with a luminosity of 72841. I'm not sure if that's the brightest out there, but I do know that it is indeed very bright.
RS 1228-477-0-0-24

I found a massive one, or should I say 2 of them. 

I found a massive one, or should I say 2 of them. 

Actually, the luminosity is much too low in Space Engine.
According to Wikipedia, has 'R136a1' a solar luminosity of 8710000!

What seems to be quite normal for Wolf-Rayet stars.