Platais 8

(MWSC 1629; OCSN 251)

0.98 UTI

0.88

C_N

1.0

C_dens

1.0

C_C3

1.0

C_lit

1.0

C_dup

N₅₀ (P>50% members) 452

Stellar density (N₅₀/rad) 9.3 [N/pc²]

C3 classification AA

C_N 0.88 Rich
C_dens 1.0 Very dense
C_C3 1.0 Very high quality
C_lit 1.0 Very well-studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

MOCA 🔍 CDS 🔍 Simbad 🔍 CDS (α, δ) 🔍 Simbad (α, δ)

Overview

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Platais 8 is a rich, very dense object of very high C3 quality. Its parallax locates it at a very close distance, near the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, young cluster, but with a large variance across recent sources for the absorption and mass parameters (see Parameters). It is very well-studied in the literature.

Very close Low extinction Near-solar metallicity Young

Liu et al. (2025)
Classified as primordial binary cluster 267 along with IC_2602.

Palma et al. (2025)
Part of multiple system G207, along with IC_2391, IC_2602 and HSC_2231.

Cavallo et al. (2024)
Gold sample.

Almeida et al. (2025)
Mass determination: good fit. Isochrone match: good fit. Gold sample.

Data

🔍 Search references for Platais 8 in: SciX Simbad

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Reference	Year	RA [deg]	DEC [deg]	Plx [mas]	pmRA [mas/yr]	pmDE [mas/yr]	Rv [km/s]
UCC	99999–	137.052	-58.656	7.34	-15.479	14.008	20.535
Li et al.	2025	136.718	-58.685	7.415	-15.596	14.474	–
Almeida et al.	2025	136.864	-58.361	–	–	–	–
Alfonso et al.	2024	137.467	-56.954	7.352	-16.213	13.769	–
Hunt & Reffert	2024	136.895	-59.309	7.427	-16.238	13.743	18.521
Cavallo et al.	2024	137.331	-57.241	7.435	–	–	–
Hunt & Reffert	2023	136.895	-59.309	7.427	-16.238	13.743	18.521
Almeida et al.	2023	137.221	-58.381	–	–	–	–
Qin et al.	2023	137.04	-59.36	7.45	-16.31	13.38	22.14
Just et al.	2023	136.871	-59.157	–	–	–	–
He et al.	2022	136.828	-58.473	7.358	-15.744	14.079	–
Dias et al.	2021	136.864	-58.361	7.409	-15.651	14.512	21.173
Cantat-Gaudin et al.	2020	136.718	-58.685	7.415	-15.596	14.474	–
Cantat-Gaudin & Anders	2020	136.718	-58.685	7.415	-15.596	14.474	–
Soubiran et al.	2018	136.718	-58.685	–	–	–	20.64
Cantat-Gaudin et al.	2018	136.718	-58.685	7.415	-15.596	14.474	–
Yen et al.	2018	136.687	-58.987	7.45	-15.83	14.73	–
Kharchenko et al.	2016	136.871	-59.157	–	–	–	–
Kharchenko et al.	2013	136.875	-59.16	–	-15.0	14.8	17.3
Gozha et al.	2012	137.375	-59.128	–	–	–	–
Piskunov et al.	2008	136.946	-59.137	–	–	–	–
Kharchenko et al.	2007	137.37	-59.13	–	3.0	–	17.32
Piskunov et al.	2007	136.946	-59.137	–	–	–	–
van den Bergh	2006	137.375	-59.128	–	–	–	–
Kharchenko et al.	2005	136.95	-59.14	–	-15.83	14.8	17.32
Dias et al.	2002	137.375	-59.128	–	-15.67	15.83	17.32

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

Reference	Year	Dist [kpc]	Av [mag]	DAv [mag]	Age [Myr]	[Fe/H] [dex]	Mass [Msun]	B_frac	BSS
UCC	99999–	0.13	0.07	0.72	51	-0.050	129	0.36	–
Liu et al.	2025	0.15	0.02	–	29	–	–	–	–
Li et al.	2025	0.15	0.22	–	38	-0.053	–	–	–
Almeida et al.	2025	0.13	0.19	–	37	–	113	–	–
Alfonso et al.	2024	0.13	0.14	–	29	-0.050	–	–	–
Hunt & Reffert	2024	–	–	–	–	–	44⁽¹⁾	–	–
Cavallo et al.	2024	0.13	0.64	–	49	0.160	–	–	–
Hunt & Reffert	2023	0.13	0.18	0.72	31	–	–	–	–
Almeida et al.	2023	0.14	0.06	–	51	0.153	129⁽¹⁾	0.36	–
Qin et al.	2023	0.15	0.25	–	35	–	–	–	–
Just et al.	2023	–	–	–	56	–	12	–	–
He et al.	2022	–	0.05	–	32	–	–	–	–
Dias et al.	2021	0.13	0.19	–	37	-0.050	–	–	–
Cantat-Gaudin et al.	2020	0.13	0.14	–	30	–	–	–	–
Cantat-Gaudin & Anders	2020	0.13	–	–	–	–	–	–	–
Soubiran et al.	2018	0.13	–	–	–	–	–	–	–
Cantat-Gaudin et al.	2018	0.13	–	–	–	–	–	–	–
Yen et al.	2018	0.14	0.07	–	79	–	–	–	–
Kharchenko et al.	2016	0.14	0.00	–	56	–	–	–	–
Kharchenko et al.	2013	0.14	0.00	–	56	-0.292	–	–	–
Gozha et al.	2012	0.13	–	–	60	–	1202	–	–
Piskunov et al.	2008	0.15	0.00	–	56	–	698⁽¹⁾	–	–
Piskunov et al.	2007	0.15	0.00	–	56	–	546	–	–
van den Bergh	2006	0.13	–	–	60	–	–	–	–
Kharchenko et al.	2005	0.15	0.00	–	56	–	–	–	–
Dias et al.	2002	0.13	–	–	60	-0.296	–	–	–

(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.

Visualization

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