Deleted member 110222
D
What defines it? Why is it different to a "normal" nebula like say, the Eagle Nebula?
Planetary nebulae are called that because early astronomers thought they looked a bit like planets, although they knew they were NOT planets.
They are usually supernova remnants - the remains of a dead star that exploded.
Ordinary nebulae are big clouds of gas & dust, often where stars are being formed.
They are usually supernova remnants - the remains of a dead star that exploded.
Ordinary nebulae are big clouds of gas & dust, often where stars are being formed.
Just some points to consider:
In astronomy, planetary nebulae are left over from when a star dies, but isn't large enough for a supernova. It swells into a red giant, loses its outer layers to space, and the remaining matter collapses into a white dwarf. If the star does end with a supernova, it will leave behind a neutron star or a black hole, and the remaining "nebula" is just considered to be a supernova remnant.
In game, what we see are these supernova remnants, and the game considers them to be planetary nebulae, even though the terminology isn't quite right. I don't think there are instances of these in-game that have white dwarfs at the center, as they should in order to have that name.
It's a little confusing if you try to match up what's in the game with real astronomy information. Technically these things are all very similar, just with slightly different cases for how the star ended its life, and what got left behind.
In both astronomy and in the game, a normal nebula is a large cloud of gas and dust, and it may be dozens or hundreds of lightyears across, and can contain many stars. In most cases, they're illuminated by stars wontained within, or are reflecting light from nearby stars. And while they look bright and colorful in photography, they're actually quite dimly lit, and within them the gas and dust is lower in density than any vacuum we can create here on Earth.
In astronomy, planetary nebulae are left over from when a star dies, but isn't large enough for a supernova. It swells into a red giant, loses its outer layers to space, and the remaining matter collapses into a white dwarf. If the star does end with a supernova, it will leave behind a neutron star or a black hole, and the remaining "nebula" is just considered to be a supernova remnant.
In game, what we see are these supernova remnants, and the game considers them to be planetary nebulae, even though the terminology isn't quite right. I don't think there are instances of these in-game that have white dwarfs at the center, as they should in order to have that name.
It's a little confusing if you try to match up what's in the game with real astronomy information. Technically these things are all very similar, just with slightly different cases for how the star ended its life, and what got left behind.
In both astronomy and in the game, a normal nebula is a large cloud of gas and dust, and it may be dozens or hundreds of lightyears across, and can contain many stars. In most cases, they're illuminated by stars wontained within, or are reflecting light from nearby stars. And while they look bright and colorful in photography, they're actually quite dimly lit, and within them the gas and dust is lower in density than any vacuum we can create here on Earth.
Last edited:
In-game, you have two types of nebulae: "normal" nebulae, which are large, irregular in shape and don't have a star associated with their centre. Planetary/Supernova-remnant nebulae are smaller, symmetrical and have an end-life star of some kind (eg. Wolf-Rayet, S class, neutron star, black hole, etc) in their centre.
Hot, bright stars (mostly O-types) can also have little fuzzy "nebulae" attached to them, which are visible on the Galaxy map but aren't named and aren't visible anywhere else except on the Galmap. These are the blobs you can often see form a distance as you scroll the map around, especially with map filters set to deselect all stars.
Note that some in-real-life supernova remnant nebulae are portrayed in ED as normal nebulae, simply because they're too big to portray as remnants. The Crab Nebula an the Veil Nebulae come to mind.
Final fact: out there in the real universe, nebulae are lit up for a reason: usually, a hot bright star (or a bunch of such stars) nearby. There are probably plenty more nebulae out there that we can't see, simply because there's no bright stars in them, just like a streetlight in a forest will light up the nearby trees, but leave the rest of the forest in darkness. The "dark nebulae" that we do know about, like the Coal Sack, are only visible to us because they happen to be sitting in front of a large patch of bright stars, so it's blocking out their light.
In ED, it was considered too difficult to create "proper" lightsourcing for nebulae, so they are just magically lit up all by themselves. Real-world nebulae are often placed in-game alongside the real-world stars that should be making them light up, though sometimes the distances don't quite match up (like Eta Carinae and the Eta Carina Nebula, which in-game are 1000 LYs apart), but of course the procedurally-generated nebulae lack any such real-world stars. Many of the large, bright, procedurally-generated nebulae, such as the Traikaae Nebula, are far away from any bright stars that could be making them light up like that.
Hot, bright stars (mostly O-types) can also have little fuzzy "nebulae" attached to them, which are visible on the Galaxy map but aren't named and aren't visible anywhere else except on the Galmap. These are the blobs you can often see form a distance as you scroll the map around, especially with map filters set to deselect all stars.
Note that some in-real-life supernova remnant nebulae are portrayed in ED as normal nebulae, simply because they're too big to portray as remnants. The Crab Nebula an the Veil Nebulae come to mind.
Final fact: out there in the real universe, nebulae are lit up for a reason: usually, a hot bright star (or a bunch of such stars) nearby. There are probably plenty more nebulae out there that we can't see, simply because there's no bright stars in them, just like a streetlight in a forest will light up the nearby trees, but leave the rest of the forest in darkness. The "dark nebulae" that we do know about, like the Coal Sack, are only visible to us because they happen to be sitting in front of a large patch of bright stars, so it's blocking out their light.
In ED, it was considered too difficult to create "proper" lightsourcing for nebulae, so they are just magically lit up all by themselves. Real-world nebulae are often placed in-game alongside the real-world stars that should be making them light up, though sometimes the distances don't quite match up (like Eta Carinae and the Eta Carina Nebula, which in-game are 1000 LYs apart), but of course the procedurally-generated nebulae lack any such real-world stars. Many of the large, bright, procedurally-generated nebulae, such as the Traikaae Nebula, are far away from any bright stars that could be making them light up like that.
I was wondering this as well - do any intrepid explorers have pictures of in-game planetary nebulae which might help me work out if I'm actually "in" one, or near one on the galaxy map?
Or if you like purple and blue, Ghost of Jupiter. It's pretty nice, one of the first beautiful places I visited in ED.
Actually on my way to Crab now myself, roughly following the path of the Crab Nebula Expedition.
Actually on my way to Crab now myself, roughly following the path of the Crab Nebula Expedition.
As mentioned above, planetary nebula are usually pretty small. Unless you happen to find one that's deep inside the Core, there's usually only one star "inside" a planetary nebula, the central remnant star. Regular nebulae are big enough to have dozens or even hundreds of stars hiding inside them.
The Ghost of Jupiter was my first outside-the-bubble exploration foray, back in December 3301. Here's my (two year old) picture of the Ghost of Jupiter nebula, from a system just a few LYs away from it, along with a pic from the Wolf-Rayet system that's inside the nebula.
And here's a pic of the rather strikingly coloured procedurally-generated planetary nebula Cyoidai GH-U e3-3 that's out near the non-procedurally-generated Crab Nebula:
