Alessi 4

(MWSC 1786)

0.04 UTI

0.0

C_N

0.07

C_dens

0.0

C_C3

0.06

C_lit

1.0

C_dup

N_m (P>50%) 22

Core radius and density 1.6 [pc], 0.4 [pc^-2]

C3 classification DD

C_N 0.0 Sparse
C_dens 0.07 Very loose
C_C3 0.0 Very low quality
C_lit 0.06 Rarely studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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Alessi 4 is a sparse, very loose object of very low C3 quality. Its parallax locates it at a moderate distance, well above the mid-plane, affected by moderate extinction. It is catalogued as an intermediate-age cluster (see Parameters). It is rarely studied in the literature.

⚠️ 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.

Relatively close Moderate extinction Intermediate age

Bica et al. (2019)
Web updates in DAML02, some were later removed (2003 to 2010). List of clusters and alike reported by B. Alessi.

Dias et al. (2002)
Asterism (Alessi, B. S. et al. 2003, A&A 410, 565); cat V3.5 (Jan 2016)

Data

🔍 Search references for Alessi 4 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–	154.075	-34.324	0.415	-7.23	4.261	-0.493
Just et al.	2023	154.051	-34.356	–	–	–	–
Bica et al.	2019	154.051	-34.348	–	–	–	–
Kharchenko et al.	2016	154.051	-34.356	–	–	–	–
Kharchenko et al.	2013	154.057	-34.36	–	-10.65	4.48	–

💡 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–	2.34	1.51	–	355	–	307	–	–
Just et al.	2023	–	–	–	355	–	307	–	–
Kharchenko et al.	2016	2.34	1.51	–	355	–	–	–	–
Kharchenko et al.	2013	2.34	1.51	–	355	–	–	–	–

Visualization

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