According to nomanssky.gamepedia.com (starship) the Explorer ship has better stealth capabilities:
Explorer starships have better engines and hyperdrives than other ships, allowing for faster and further travel. Additionally, ships in this class have better stealth capabilities, improving their pilots' ability to remain undetected during exploration.
How does stealth work in NMS? I haven't seen any sort of cloaking or other means. Perhaps it's passive to prevent pirates from seeing you?