Ryu 399 is a sparse, moderately dense object of low C3 quality. Its parallax locates it at a moderate distance, near the mid-plane. No fundamental parameter values are available for this object. It is rarely studied in the literature, with no articles listed in the last 7 years.

⚠️ Warning: the low UTI value and no obvious signs of duplication (C_dup=1.0) indicate that this is quite probably an asterism, moving group, or artifact, and not a real open cluster.

Reference	Year	RA [deg]	DEC [deg]	Plx [mas]	pmRA [mas/yr]	pmDE [mas/yr]	Rv [km/s]
UCC	–	258.223	-39.579	0.271	-2.119	-3.564	-25.764
Bica et al.	2019	258.22	-39.561	–	–	–	–

💡 Note: The UCC values are estimated from its identified members.