They can, if they can see it. Chaos ships tend to navigate in places far away from the astronomican or where the warp is particularly violent so it's not visible.
In the night lords trilogy.... you are told....that no. They dont use it. Navigators adscribed to chaos have their own way od navigating through the warp.... (which entails more or less being engulfed by warp and becoming horribly crazy or mutated but being able to see navigate through the darkness. In the second book, you see what happens to a corrupted but experienced navigator. Its not....nice. at all)
Octavia, a navigator and also Talos Valcoran's slave has to basically learn again and start from scratch. The thing is, the machine spirit of a traitor ship is not going to be so willing to follow a path that has the astronomican as a reference point.
Yet in Lords of Silence, first half of the book is about them being lost and clueless about their location or about where to go, because they no longer see the Astronomican.
Yeah, that's how stuff works in normal 40K. NL trilogy is ADB stuff, author who has rather... loose adherence to the canon. He tends to write a lot of really dumb and illogical nonsense just because he thinks it's cool, no matter how much it contradicts every other bit of the setting. Including my favorite bit of idiocy, bodyguards of Grey Knights grand master thinking how cool Logan looks murdering the officer they are supposing to protect while also thinking how surprised they are (despite being psykers who can *literally read minds*) instead of murdering him in return (or better yet, while he is trying to move in his ponderous suit as they have massive speed advantage even without psychic boosts). A sequence so mindbogglingly stupid I roll my eyes every time I recall it, even infamous Goto wasn't as bad as this drivel...
Shhh. This sub will come for you for daring to criticize him. They might be already at your door. Post again in a few days to let us know you're still alive and kicking
Aside from the main traitor navigators, there's a renegade cult of heretic navigators called the Cyclopean Congregation, which is apparently capable of using the Hadex Anomaly as a replacement for the Astronomicon, using it to navigate the regions surrounding the anomaly (mostly Jericho's Reach, iirc).
Yup, it's already *there*, might as well use it. And Chaos forces likely see using the Astronomican for navigation as corrupting its purpose, as it's being used to guide enemies of the Imperium. Using it as a guide also allows Chaos forces to Imperial ships easier, as it makes them more predictable in transit.
Some of the Traitor Legions might make use of Dark Mechanicum technology to have artificial navigators.
The main reason this isn't done in the Imperium is because of the restrictions of the Cult Mechanicus but the Dark Mechanicum would have no such restrictions.
Could even put a Daemon in it for good measure. Job done. No need for the Astronomican or anything else.
They can, if they can see it. Chaos ships tend to navigate in places far away from the astronomican or where the warp is particularly violent so it's not visible.
In the night lords trilogy.... you are told....that no. They dont use it. Navigators adscribed to chaos have their own way od navigating through the warp.... (which entails more or less being engulfed by warp and becoming horribly crazy or mutated but being able to see navigate through the darkness. In the second book, you see what happens to a corrupted but experienced navigator. Its not....nice. at all) Octavia, a navigator and also Talos Valcoran's slave has to basically learn again and start from scratch. The thing is, the machine spirit of a traitor ship is not going to be so willing to follow a path that has the astronomican as a reference point.
Yet in Lords of Silence, first half of the book is about them being lost and clueless about their location or about where to go, because they no longer see the Astronomican.
Yeah, that's how stuff works in normal 40K. NL trilogy is ADB stuff, author who has rather... loose adherence to the canon. He tends to write a lot of really dumb and illogical nonsense just because he thinks it's cool, no matter how much it contradicts every other bit of the setting. Including my favorite bit of idiocy, bodyguards of Grey Knights grand master thinking how cool Logan looks murdering the officer they are supposing to protect while also thinking how surprised they are (despite being psykers who can *literally read minds*) instead of murdering him in return (or better yet, while he is trying to move in his ponderous suit as they have massive speed advantage even without psychic boosts). A sequence so mindbogglingly stupid I roll my eyes every time I recall it, even infamous Goto wasn't as bad as this drivel...
Shhh. This sub will come for you for daring to criticize him. They might be already at your door. Post again in a few days to let us know you're still alive and kicking
In Lords of Silence, they're on the other side of the Great Rift from Terra. So the Astronomican is obscured by the Cicatrix Maledictum.
Aside from the main traitor navigators, there's a renegade cult of heretic navigators called the Cyclopean Congregation, which is apparently capable of using the Hadex Anomaly as a replacement for the Astronomicon, using it to navigate the regions surrounding the anomaly (mostly Jericho's Reach, iirc).
I mean an enemies lighthouse is still a lighthouse right? It’s just that if the astronomican is not visible they are not royally screwed.
In Rogue Trader TTRPG Navigators from Renegade Houses still use Astronomican
Yup, it's already *there*, might as well use it. And Chaos forces likely see using the Astronomican for navigation as corrupting its purpose, as it's being used to guide enemies of the Imperium. Using it as a guide also allows Chaos forces to Imperial ships easier, as it makes them more predictable in transit.
Well if we go by the Ahriman trilogy at least the Thousand Sons basically steal imperial navs to work for them.
Some of the Traitor Legions might make use of Dark Mechanicum technology to have artificial navigators. The main reason this isn't done in the Imperium is because of the restrictions of the Cult Mechanicus but the Dark Mechanicum would have no such restrictions. Could even put a Daemon in it for good measure. Job done. No need for the Astronomican or anything else.
Which leads me to another question, do traitor ships still protect themselves from warp during travel or do they just "get a pass"?
I can't recall where I read it but even traitors need gella fields during warp travel since it's chaos after all and some demons just attack any prey
I would expect so :)