An Energetic Protostar

Day 18 of the 2024 Space Telescope Advent Calendar: an energetic protostar. FS Tau is a multi-star system made up of FS Tau A, the bright starlike object near the middle of the image, and FS Tau B (Haro 6-5B), the bright object to the far right that is partially obscured by a dark, vertical lane of dust. The young objects are surrounded by the softly illuminated gas and dust of this stellar nursery. The system is only about 2.8 million years old, very young for a star system. FS Tau B is a newly forming star, or protostar, and is surrounded by a protoplanetary disc, a pancake-shape collection of dust and gas left over from the formation of the star that will eventually coalesce into planets. Protostars are known to eject fast-moving, columnlike streams of energized material called jets, and FS Tau B provides a striking example of this phenomenon. The protostar is the source of an unusual asymmetric, double-sided jet, visible here in blue.

See the full advent calendar here, where a new image will be revealed each day until December 25.