Aeldari in Distress: Locations & Choices: In Distress And Rogue Trader

Start from the Janus system. Look towards the bottom right of your star map. You'll want to head right, towards Langrenn's Belt, and then down to the Forgotten Twins system. Once you arrive, interact with the derelict ship. It's not super eventful, mostly just giving you some insight from Yrliet about its Aeldari origins.

This system is located towards the very top of your star map in Chapter 2. To get there from the Forgotten Twins, you'll need to navigate through a few systems: Mu-Rho 79, Mundus Nulius, Mundus Valancius, and Narmer IV, before heading right to Odaenathus XI. Heads up: This system is crawling with Drukhari. There are four Drukhari vessels guarding points of interest. If you get too close to them or the planets they're guarding, you'll trigger a space battle. These guys call for backup, so it can get really tough. Your best bet is to carefully navigate through the gaps between them, avoiding the planets entirely, to reach the Aeldari vessel. You can then scavenge and loot the ship for more information.

This is the final system and it's located on the far left of the star map, so it's a bit of a trek. A good way to get there is to head back to Telikos Epsilon (Janus). From there, go to Orsellio Prophecy, then navigate left to Adermatt II. From Adermatt II, move down one system to reach Tenebris Aquae. When you arrive, you'll find the Imperial Fleet fighting an Aeldari ship. You have a choice here: you can either help the Aeldari by attacking the two Imperial vessels, which lets the Aeldari ship escape, or you can tell the Imperial vessel to stand down. If you do the latter, the Aeldari ship will try to flee, but its engines will go into overdrive and destroy the ship when you catch up. Sadly, you can't actually make contact with the Aeldari vessel here, but this is the last objective for the mission. Don't stress too much about the outcome here; you'll get more context for Yrliet's questline later in Chapter 3.