Alessi 1

(Casado Alessi 1; MWSC 88; CA 1; LeDrew 1)

0.95 UTI

0.74

C_N

1.0

C_dens

1.0

C_C3

1.0

C_lit

1.0

C_dup

N₅₀ (P>50% members) 99

Stellar density (N₅₀/rad) 10.9 [N/pc²]

C3 classification AA

C_N 0.74 Moderately populated
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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Alessi 1 is a moderately populated, very dense object of very high C3 quality. Its parallax locates it at a close distance, below the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, intermediate-age cluster, but with a large variance across recent sources for the absorption and metallicity parameters (see Parameters). It is very well-studied in the literature.

Close Low extinction Near-solar metallicity Intermediate age

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

Cavallo et al. (2024)
Gold sample.

Data

🔍 Search references for Alessi 1 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–	13.336	49.551	1.411	6.484	-6.391	-4.284
Li et al.	2025	13.343	49.536	1.39	6.536	-6.245	–
Hu & Soubiran	2025	13.486	49.518	–	–	–	–
Wei et al.	2025	13.361	49.531	1.415	6.482	-6.382	–
Almeida et al.	2025	13.319	49.536	–	–	–	–
Alfonso et al.	2024	13.441	49.442	1.36	6.369	-6.024	–
Zhang et al.	2024	13.355	49.548	–	–	–	–
Hunt & Reffert	2024	13.355	49.548	1.41	6.47	-6.402	-5.191
Cavallo et al.	2024	13.486	49.518	1.409	–	–	–
Hunt & Reffert	2023	13.355	49.548	1.41	6.47	-6.402	-5.191
Just et al.	2023	13.318	49.477	–	–	–	–
He et al.	2022	13.356	49.511	1.411	6.476	-6.42	–
Tarricq et al.	2022	13.283	49.516	1.424	6.48	-6.435	–
Dias et al.	2021	13.319	49.536	1.394	6.548	-6.27	-3.343
Cantat-Gaudin et al.	2020	13.343	49.536	1.39	6.536	-6.245	–
Cantat-Gaudin & Anders	2020	13.343	49.536	1.39	6.536	-6.245	–
Bossini et al.	2019	13.343	49.536	–	–	–	–
Soubiran et al.	2018	13.343	49.536	–	–	–	-3.73
Bica et al.	2019	13.367	49.57	–	–	–	–
Cantat-Gaudin et al.	2018	13.343	49.536	1.39	6.536	-6.245	–
Loktin & Popova	2017	13.26	49.765	–	0.857	-4.489	6.0
Kharchenko et al.	2016	13.318	49.477	–	–	–	–
Dias et al.	2014	13.363	49.567	–	0.04	-4.39	–
Kharchenko et al.	2013	13.327	49.48	–	6.13	-7.53	6.0
Gozha et al.	2012	13.362	49.567	–	–	–	–
Kharchenko et al.	2012	13.327	49.48	–	6.13	-7.53	6.0
Piskunov et al.	2008	13.352	49.571	–	–	–	–
Kharchenko et al.	2007	13.36	49.57	–	0.45	–	6.0
Piskunov et al.	2007	13.352	49.571	–	–	–	–
van den Bergh	2006	13.25	49.55	–	–	–	–
Kharchenko et al.	2005	13.36	49.57	–	6.51	-7.7	–
Alessi et al.	2003	13.25	49.55	–	6.7	-7.8	–
Dias et al.	2002	13.363	49.567	–	6.74	-7.79	6.0

💡 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–	0.69	0.31	0.67	708	-0.084	169	0.53	–
Li et al.	2025	0.67	0.32	–	1142	-0.123	–	–	–
Hu & Soubiran	2025	–	–	–	–	-0.190⁽⁵⁾	–	–	–
Wei et al.	2025	0.66	0.08	–	692	0.500	169	0.53	–
Almeida et al.	2025	0.68	0.42	–	984	–	87	–	–
Alfonso et al.	2024	0.69	0.08	–	1153	-0.108	–	–	–
Zhang et al.	2024	–	–	–	–	-0.059⁽¹⁾	–	–	–
Hunt & Reffert	2024	–	–	–	–	–	61⁽¹⁾	–	–
Cavallo et al.	2024	0.67	0.49	–	794	0.140	–	–	–
Hunt & Reffert	2023	0.66	0.21	0.67	748	–	–	–	–
Just et al.	2023	–	–	–	692	–	136	–	–
He et al.	2022	–	0.60	–	501	–	–	–	–
Tarricq et al.	2022	0.68	–	–	1514	–	–	–	–
Dias et al.	2021	0.68	0.42	–	984	-0.109	–	–	–
Cantat-Gaudin et al.	2020	0.69	0.08	–	1445	–	–	–	–
Cantat-Gaudin & Anders	2020	0.70	–	–	–	–	–	–	–
Bossini et al.	2019	0.71	0.32	–	861	0.000	–	–	–
Soubiran et al.	2018	0.70	–	–	–	–	–	–	–
Cantat-Gaudin et al.	2018	0.70	–	–	–	–	–	–	–
Loktin & Popova	2017	0.40	0.25	–	216	–	–	–	–
Kharchenko et al.	2016	0.75	0.31	–	692	–	–	–	–
Kharchenko et al.	2013	0.75	0.31	–	692	–	–	–	–
Gozha et al.	2012	0.30	–	–	158	–	324	–	–
Kharchenko et al.	2012	0.75	0.31	–	692	–	–	–	–
Piskunov et al.	2008	0.80	0.31	–	708	–	618⁽¹⁾	–	–
Piskunov et al.	2007	0.80	0.31	–	708	–	245	–	–
van den Bergh	2006	0.30	0.28	–	158	–	–	–	–
Kharchenko et al.	2005	0.80	0.31	–	708	–	–	–	–
Dias et al.	2002	0.30	0.28	–	158	–	–	–	–

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

Visualization

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