Gas giant
The smallest known extrasolar planet that is likely a "gas planet" is Kepler-138d, which has the same mass as Earth but is 60% larger and therefore has a density that indicates a thick gas envelope.
2019 AQ3
orbit has the smallest aphelion of any known asteroid in the Solar System, never distancing itself more than 0.774 AU from the Sun (77% of Earth's average orbital distance). Before its discovery, the record was held by at an aphelion of 0.804 AU, which is notably larger. orbit also has a semi-major axis below that of Venus (0.723 AU) and an orbital period of 165 days, which is the second shortest among all asteroids. (The record 161-day orbit of is poorly defined and still may change considerably).