Platais 8

Platais 8, also known as the a Carinae cluster or HIP 45080 Cluster is a small and faint open cluster located in the southern constellation Carina. It is estimated to be 440 light years distant based on parallax measurements.^[1]

Platais 8
Observation data (J2000.0 epoch)
Right ascension	09h 06m 52.3s[1]
Declination	−58° 41′ 06″[1]
Distance	440±1 ly (134.9±0.6 pc[1])
Apparent dimensions (V)	3.45° × 3.45°[1]
Physical characteristics
Mass	546+265 −178[2] M☉
Radius	37.2 ± 4.9 ly (11.4 ± 1.5 pc)[2]
Estimated age	60±15 Ma[3]
Other designations	Platais 8, HIP 45080 Cluster, MWSC 1629
Associations
Constellation	Carina
See also: Open cluster, List of open clusters

The cluster was first noticed by astronomer Imants Platais in 1998.^[4] A 2005 paper suggests that Platais 8 might have formed near the area where the Scorpius-Centaurus association is located. ^[5] The SIMBAD database lists the cluster having 28,185 members^[6] but the majority of the stars are field stars. In fact, there are only 32 members physically associated with the cluster.^[1] The cluster has a combined mass of 546 M_☉ and a radius of 37.2 light years. Platais 8 is rather young, with an age of only 60 million years.^[3]

Members

These are the members of the cluster as identified by Canat-Gaudin et al. (2018)

Members of Cl Platais 8^[7]

Name	mv	MK Type	Dist. (ly)	Notes
HD 76230	6.57	A0 V	410	Binary
HD 78802	7.33	A2 IV	467
HD 76413	7.48	A3 V	417
HD 80628	7.57	A0/1 V	442
HD 78761	7.68	A2 V	454
HD 78027	7.88	A1 V	444

The cluster also has one potential stream star located in Volans^[1] and was considered to be a background object prior to 2020.

Name	mv	MK Type	Dist. (ly)	Notes
HD 71863	5.94	G8/K0 III	421	HR 3346