These might be planets, moons, or asteroids for example, but excluding the Sun, Jupiter and Saturn.
Dunn et al. (2021) A Low Signal Detection of X‐Rays From Uranus open access
Space.com's Uranus is belching X-rays and is weirder than we ever thought
Chandra X-ray Observatory Uranus: First X-rays From Uranus Discovered
Chandra X-ray Observatory More images ...