Cyg OB2

0.17 UTI

0.8

C_N

1.0

C_dens

1.0

C_C3

0.25

C_lit

0.25

C_dup

N₅₀ (P>50% members) 231

Stellar density (N₅₀/rad) 45.4 [N/pc²]

C3 classification AA

C_N 0.8 Rich
C_dens 1.0 Very dense
C_C3 1.0 Very high quality
C_lit 0.25 Poorly studied
C_dup 0.25 Possibly duplicate

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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Cyg OB2 is a rich, very dense object of very high C3 quality. Its parallax locates it at a relatively close distance, near the mid-plane, affected by high extinction. It is catalogued as an extremely massive, very young cluster (see Parameters). It is poorly studied in the literature, with no articles listed in the last 18 years.

⚠️ Warning: This is possibly a duplicate object, which shares a significant percentage of members with at least one previously reported entry. See table with shared members information.

Relatively close High extinction Extremely massive Very young

Data

🔍 Search references for Cyg OB2 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–	308.307	41.3	0.58	-2.72	-4.407	-8.189
Piskunov et al.	2008	308.299	41.304	–	–	–	–
Kharchenko et al.	2007	308.1	41.28	–	0.6	–	-28.0
Piskunov et al.	2007	308.299	41.304	–	–	–	–
Kharchenko et al.	2005	308.31	41.31	–	-1.6	-4.72	-28.0

💡 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–	1.5	4.03	–	5	–	14588	–	–
Piskunov et al.	2008	1.50	4.03	–	5	–	25645⁽¹⁾	–	–
Piskunov et al.	2007	1.50	4.03	–	5	–	3532	–	–
Kharchenko et al.	2005	1.50	4.03	–	5	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
Bica 2	74.9	308.31	41.3	0.58	-2.68	-4.41	-13.56	0.78
FSR 0238	19.0	308.63	41.39	0.59	-2.84	-4.53	-27.33	0.88
G 80.35+0.72	4.3	308.43	41.38	0.54	-2.83	-4.13	-4.79	0.16
FSR 0236	3.9	308.15	41.43	0.57	-2.41	-4.11	55.7	0.69
OC 0129	1.3	308.06	41.46	0.58	-2.53	-4.04	57.08	0.25
OC 0128	0.9	307.98	40.8	0.58	-2.97	-4.4	38.32	0.67

💡 Note: The % column shows the percentage of members that Cyg OB2 shares with each listed object.

Visualization

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