Mon OB1-D

0.39 UTI

0.9

C_N

1.0

C_dens

0.75

C_C3

0.35

C_lit

0.58

C_dup

N₅₀ (P>50% members) 491

Stellar density (N₅₀/rad) 110.2 [N/pc²]

C3 classification AB

C_N 0.9 Very rich
C_dens 1.0 Very dense
C_C3 0.75 High quality
C_lit 0.35 Poorly studied
C_dup 0.58 Likely unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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Mon OB1-D is a very rich, very dense object of high C3 quality. Its parallax locates it at a close distance, near the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, very young cluster, but with a large variance across recent sources for the absorption and mass parameters (see Parameters). It was recently reported in the literature.

Note: This is likely a unique object, which shares a moderate percentage of members with at least one previously reported entry. See table with shared members information.

Close Low extinction Near-solar metallicity Very young

Liu et al. (2025)
Classified as primordial binary cluster 274 along with NGC_2264.

Palma et al. (2025)
Classified as optical pair (not dynamically associated) P235, along with NGC_2264.

Cavallo et al. (2024)
Wood sample.

Data

🔍 Search references for Mon OB1-D 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–	100.246	9.621	1.378	-2.089	-3.702	21.972
Wei et al.	2025	100.226	9.724	1.396	-1.862	-3.671	–
Zhang et al.	2024	100.274	9.573	–	–	–	–
Hunt & Reffert	2024	100.274	9.573	1.378	-2.378	-3.723	21.55
Cavallo et al.	2024	100.277	9.595	1.376	–	–	–
Hunt & Reffert	2023	100.274	9.573	1.378	-2.378	-3.723	21.55

💡 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–	0.695	0.41	1.61	10	0.250	760	0.58	–
Liu et al.	2025	0.70	0.07	–	8	–	–	–	–
Wei et al.	2025	0.61	0.38	–	13	0.250	1408	0.58	–
Zhang et al.	2024	–	–	–	–	0.203⁽¹⁾	–	–	–
Hunt & Reffert	2024	–	–	–	–	–	112⁽¹⁾	–	–
Cavallo et al.	2024	0.88	0.74	–	28	0.330	–	–	–
Hunt & Reffert	2023	0.69	0.44	1.61	6	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
NGC 2264	41.5	100.21	9.87	1.39	-1.69	-3.63	20.84	0.95
LP 44	24.2	100.27	9.56	1.38	-1.99	-3.93	19.6	0.51

💡 Note: The % column shows the percentage of members that Mon OB1-D shares with each listed object.

Visualization

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