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Unrealistic stars.

Posted: 23 Sep 2017 05:13
by Mouthwash
The upper limit for stellar mass is believed to be 150 solar masses, and such stars are extremely rare. I just entered a randomly generated galaxy and found - purely by accident, no searches involved - a 300 solar mass star, with a diameter of 29 AU (nearly twice as large as UY Scuti, which, by the way, has 10 solar masses).

The star is called 0-0-0-134-21922-0-0-306. Can't there at least be basic physical restraints in the generator?

Unrealistic stars.

Posted: 23 Sep 2017 07:20
by Gnargenox
 RMC136a1=315+60/−50 M☉

Unrealistic stars.

Posted: 23 Sep 2017 08:20
by problemecium
Finding an anomalously large star just means you got lucky. They're also easy to spot on account of their size. Find a bunch of these and you may have a point relating to the statistical distributions.

Unrealistic stars.

Posted: 23 Sep 2017 08:22
by JackDole
R136a1 is a very massive star, but has a comparatively small diameter.
According to Wikipedia 315 solar masses and 28.8 - 35.4 solar diameters. (About 0.3 au)

This seems to be the rule in real life. Stars with very high mass, but comparatively low diameter, and stars with lesser mass, but very large diameter.
For example UY Scuti with 7-10 solar masses and 1708 ± 192 solar diameters. According to Wikipedia.
(Other sources say 20 - 40 solar masses)

Unrealistic stars.

Posted: 23 Sep 2017 09:01
by Mouthwash
problemecium wrote:
R136a1 is a very massive star, but has a comparatively small diameter.
According to Wikipedia 315 solar masses and 28.8 - 35.4 solar diameters. (About 0.3 au)

This seems to be the rule in real life. Stars with very high mass, but comparatively low diameter, and stars with lesser mass, but very large diameter.
For example UY Scuti with 7-10 solar masses and 1708 ± 192 solar diameters. According to Wikipedia.
(Other sources say 20 - 40 solar masses

I apparently read some garbage science journalism, then. :cry:

problemecium wrote:
Finding an anomalously large star just means you got lucky. They're also easy to spot on account of their size. Find a bunch of these and you may have a point relating to the statistical distributions.

I found an even bigger star, 0-0-0-134-21922-0-0-27, not too far away by eyeball. You're right that bigger stars are easier to spot, but that's also true in real life and I'm doing a million times better than the entire astronomical community. Also, there's the size issue. UY Scuti is the largest star ever discovered. I'm finding stars twice as big whenever I glance around.

EDIT: Actually, now that I compare it to the Milky Way, it seems that I can't spot any stars at that distance. They don't even show up. Seems like that was just a galaxy of incredibly massive stars. Is that scientifically accurate? Age could explain size but not mass.

Gnargenox wrote:
RMC136a1=315+60/−50 M☉

Okay dude, what?

Unrealistic stars.

Posted: 23 Sep 2017 09:22
by Mouthwash
RS 0-0-0-134-7430-0-0-268. Red supergiant over a hundred AU wide. It would extend past the orbit of Pluto, were it in the center of the solar system.

I think the star generator may have a tiny bit of a issue here. Maybe it's good that solar masses seem to be capped at 300.

EDIT: So it seems 0-0-0-134-14722-0-0-292 is the biggest one I've found. 114 AU. It also has an orbiting black hole... I can't think of anything to say here.

Unrealistic stars.

Posted: 23 Sep 2017 10:37
by spaceguy
Mouthwash wrote:
Source of the post Actually, now that I compare it to the Milky Way, it seems that I can't spot any stars at that distance. They don't even show up. Seems like that was just a galaxy of incredibly massive stars. Is that scientifically accurate? Age could explain size but not mass.

I don't think so. Massive stars in general, even in active star formation galaxies, are extremely rare. 300 solar mass stars are theoretical and no one has seen them. So I find it a bit odd that you can find a lot of these stars by searching for them, even if by statistical distribution they're ''rare'' in the engine. But they don't feel rare, especially when exploring procedural galaxies. I mean yes it could be observational bias, but I always find myself finding way too many 300 solar mass stars. Maybe the engine compensates by balancing the mass distribution in massive stars so it doesn't have to generate millions more smaller stars, idk.

Unrealistic stars.

Posted: 23 Sep 2017 10:41
by Gnargenox
Mouthwash wrote:
Source of the post Okay dude, what?

Space Engine would not be a proper simulator of the observable universe if it didn't include the possibility of 300+ M stars. Some galaxies have an over abundance certainly, just as there is the over abundance of planets with life. Just so the layman wont have to spend a week hunting for one.

Unrealistic stars.

Posted: 23 Sep 2017 10:43
by Mouthwash
Gnargenox wrote:
Mouthwash wrote:
Source of the post Okay dude, what?

Space Engine would not be a proper simulator of the observable universe if it didn't include the possibility of 300+ M stars. Some galaxies have an over abundance certainly, just as there is the over abundance of planets with life. Just so the layman wont have to spend a week hunting for one.

And you talk about what a 'proper simulator' is with a straight face?

Unrealistic stars.

Posted: 23 Sep 2017 10:48
by Gnargenox
Link me to a better one. :o

Unrealistic stars.

Posted: 26 Sep 2017 01:29
by A-L-E-X
if 300 M stars are only theoretical but present in the program then we should also have the theoretical quark stars too :P

Unrealistic stars.

Posted: 27 Sep 2017 14:21
by donatelo200
300 M stars exist and we have seen them as Gnargenox pointed out.   R136a1 to be specific.  Now for stars over 100Au in diameter.... well that is probably unrealistic unless it is a Quasi star.  Even so Quasi stars have not been observed and were thought only possible in the very early universe.

Edit: Quasi stars are not currently in Space Engine anyways.
Edit Edit: In the closed beta right now the mass cap for non-catalog stars has been moved down to 180 M so the concern is mostly void.

Unrealistic stars.

Posted: 27 Sep 2017 14:47
by A-L-E-X
It makes me wonder how did R136a1 happen if it is such an outlier? And there are others in the same cluster of a similar mass? And how come the LMC has it and none have been found in our galaxy or Andromeda M31 which are both much larger?

Unrealistic stars.

Posted: 27 Sep 2017 14:52
by donatelo200
Well we can't observe most of our galaxy due to us being in it and the Andromeda galaxy is too far away for us to get any accurate readings on a single star.

Unrealistic stars.

Posted: 27 Sep 2017 15:13
by A-L-E-X
Good point, so they might be near the center of the galaxy, most of which is obscured by dust?

Makes you wonder if there might be even larger stars than that one.  In our galaxy, M31 or M87 Giant galaxy in Virgo!