Alessi 18

(MWSC 1284; DSH J0737.1-2623)

0.46 UTI

0.0

C_N

0.8

C_dens

0.12

C_C3

0.69

C_lit

1.0

C_dup

N₅₀ (P>50% members) 22

Stellar density (N₅₀/rad) 4.0 [N/pc²]

C3 classification DC

C_N 0.0 Sparse
C_dens 0.8 Dense
C_C3 0.12 Very low quality
C_lit 0.69 Moderately studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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Alessi 18 is a sparse, dense object of very low C3 quality. Its parallax locates it at a very large^* distance, below the mid-plane, affected by moderate extinction. It is catalogued as a near-solar metallicity, intermediate-age cluster, but with a large variance across recent sources for the age parameter (see Parameters). It is moderately studied in the literature.

(*): The parallax distance estimate (~10.05 kpc) differs significantly from the median photometric distance (~6.29 kpc).

Very distant Moderate extinction Near-solar metallicity Intermediate age

Almeida et al. (2025)
Mass determination: invalid due to poor quality CMD. Isochrone match: worst fit.

Data

🔍 Search references for Alessi 18 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–	114.296	-26.39	0.1	-1.267	1.883	124.549
Almeida et al.	2025	114.295	-26.39	–	–	–	–
Celli et al.	2024	114.296	-26.388	–	–	–	–
Just et al.	2023	114.286	-26.383	–	–	–	–
Dias et al.	2021	114.295	-26.39	0.131	-1.221	1.886	–
Cantat-Gaudin et al.	2020	114.295	-26.386	0.126	-1.261	1.79	–
Cantat-Gaudin & Anders	2020	114.295	-26.386	0.126	-1.261	1.79	–
Bica et al.	2019	114.29	-26.388	–	–	–	–
Cantat-Gaudin et al.	2018	114.295	-26.386	0.126	-1.261	1.79	–
Kharchenko et al.	2016	114.286	-26.383	–	–	–	–
Kharchenko et al.	2013	114.292	-26.385	–	-3.65	1.48	–
Kronberger et al.	2006	114.296	-26.388	–	–	–	–
Dias et al.	2002	114.296	-26.388	–	-1.39	-0.34	–

💡 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–	6.29	2.02	–	841	-0.272	311	–	–
Almeida et al.	2025	4.05	2.04	–	659	–	270	–	–
Celli et al.	2024	–	–	–	5	–	311	–	–
Just et al.	2023	–	–	–	1023	–	438	–	–
Dias et al.	2021	4.05	2.04	–	659	-0.272	–	–	–
Cantat-Gaudin et al.	2020	7.21	2.48	–	5	–	–	–	–
Cantat-Gaudin & Anders	2020	6.46	–	–	–	–	–	–	–
Cantat-Gaudin et al.	2018	6.46	–	–	–	–	–	–	–
Kharchenko et al.	2016	6.29	2.00	–	1023	–	–	–	–
Kharchenko et al.	2013	6.29	2.00	–	1023	–	–	–	–
Dias et al.	2002	6.29	2.00	–	1023	–	–	–	–

Visualization

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