Alessi 40

(ASCC 97; MWSC 2963; FoF 2405)

0.96 UTI

0.78

C_N

1.0

C_dens

1.0

C_C3

1.0

C_lit

1.0

C_dup

N₅₀ (P>50% members) 175

Stellar density (N₅₀/rad) 14.1 [N/pc²]

C3 classification AA

C_N 0.78 Rich
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 40 is a rich, very dense object of very high C3 quality. Its parallax locates it at a close distance, near the mid-plane, affected by moderate extinction. It is catalogued as a near-solar metallicity, young cluster, but with a large variance across recent sources for the metallicity and mass parameters (see Parameters). It is very well-studied in the literature.

Close Moderate extinction Near-solar metallicity Young

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

Cavallo et al. (2024)
Gold sample.

Data

🔍 Search references for Alessi 40 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–	279.285	-19.172	1.736	-2.401	-6.448	-3.707
Li et al.	2025	279.263	-19.139	1.74	-2.331	-6.508	–
Wei et al.	2025	279.329	-19.14	1.727	-2.371	-6.412	–
Almeida et al.	2025	279.3	-19.155	–	–	–	–
Alfonso et al.	2024	279.316	-19.141	1.693	-2.42	-6.418	–
Hunt & Reffert	2024	279.271	-19.168	1.737	-2.418	-6.419	-3.718
Cavallo et al.	2024	279.32	-19.18	1.737	–	–	–
Hunt & Reffert	2023	279.271	-19.168	1.737	-2.418	-6.419	-3.718
Almeida et al.	2023	279.294	-19.16	–	–	–	–
Just et al.	2023	279.217	-19.222	–	–	–	–
He et al.	2022	279.31	-19.224	1.748	-2.394	-6.453	–
Dias et al.	2021	279.3	-19.155	1.731	-2.245	-6.497	6.079
Cantat-Gaudin et al.	2020	279.263	-19.139	1.74	-2.331	-6.508	–
Cantat-Gaudin & Anders	2020	279.263	-19.139	1.74	-2.331	-6.508	–
Liu & Pang	2019	279.277	-19.156	1.773	-2.488	-6.377	–
Soubiran et al.	2018	279.263	-19.139	–	–	–	-0.34
Bica et al.	2019	279.146	-19.462	–	–	–	–
Cantat-Gaudin et al.	2018	279.263	-19.139	1.74	-2.331	-6.508	–
Loktin & Popova	2017	279.15	-19.467	–	2.641	-5.946	-16.31
Kharchenko et al.	2016	279.217	-19.222	–	–	–	–
Dias et al.	2014	279.146	-19.465	–	-0.87	-5.74	–
Kharchenko et al.	2013	279.225	-19.22	–	-0.7	-5.94	–
Piskunov et al.	2008	279.227	-19.222	–	–	–	–
Piskunov et al.	2007	279.227	-19.222	–	–	–	–
Kharchenko et al.	2005	279.24	-19.22	–	-2.09	-6.21	–
Dias et al.	2002	279.146	-19.465	–	-2.09	-6.21	-16.31

💡 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–	0.59	1.35	1.58	84	0.129	318	0.47	–
Li et al.	2025	0.53	1.44	–	106	-0.149	–	–	–
Wei et al.	2025	0.94	1.40	–	59	0.250	746	0.43	–
Almeida et al.	2025	0.56	1.45	–	169	–	82	–	–
Alfonso et al.	2024	0.60	1.17	–	88	0.105	–	–	–
Hunt & Reffert	2024	–	–	–	–	–	615⁽¹⁾	–	–
Cavallo et al.	2024	0.58	1.43	–	162	0.200	–	–	–
Hunt & Reffert	2023	0.54	1.22	1.58	123	–	–	–	–
Almeida et al.	2023	0.56	1.51	–	117	0.075	280⁽¹⁾	0.51	–
Just et al.	2023	–	–	–	76	–	46	–	–
He et al.	2022	–	1.55	–	79	–	–	–	–
Tarricq et al.	2022	0.59	–	–	112	–	–	–	–
Dias et al.	2021	0.56	1.45	–	169	0.106	–	–	–
Cantat-Gaudin et al.	2020	0.60	1.17	–	112	–	–	–	–
Cantat-Gaudin & Anders	2020	0.57	–	–	–	–	–	–	–
Liu & Pang	2019	–	–	–	59	0.500	–	–	–
Soubiran et al.	2018	0.57	–	–	–	–	–	–	–
Cantat-Gaudin et al.	2018	0.57	–	–	–	–	–	–	–
Loktin & Popova	2017	1.46	1.22	–	305	–	–	–	–
Kharchenko et al.	2016	0.59	1.35	–	76	–	–	–	–
Kharchenko et al.	2013	0.59	1.35	–	76	0.129	–	–	–
Piskunov et al.	2008	0.80	1.24	–	76	–	1112⁽¹⁾	–	–
Piskunov et al.	2007	0.80	1.24	–	76	–	318	–	–
Kharchenko et al.	2005	0.80	1.24	–	76	–	–	–	–
Dias et al.	2002	0.80	1.24	–	76	0.129	–	–	–

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

Visualization

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