NGC 1817

(Collinder 60; MWSC 484; OCL 463; FoF 0)

1.0 UTI

1.0

C_N

1.0

C_dens

1.0

C_C3

1.0

C_lit

1.0

C_dup

N₅₀ (P>50% members) 657

Stellar density (N₅₀/rad) 18.0 [N/pc²]

C3 classification AA

C_N 1.0 Very 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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NGC 1817 is a very rich, very dense object of very high C3 quality. Its parallax locates it at a relatively close distance, below the mid-plane, affected by moderate extinction. It is catalogued as a massive, near-solar metallicity, old 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.

Note: This object contains blue stragglers according to at least one source.

Note: This object shares a very small percentage of members with at least one entry reported in the same catalogue. See table with shared members information.

Relatively close Moderate extinction Massive Near-solar metallicity Old Contains BSS

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

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 1.00 (50th percentile).

Rain et al. (2021)
The parameters used to fit the isochrone: log(t)=9.04, E(b-v)=0.23 and [Fe/H]=-0.40 selected from Donati et al. (2014MNRAS.437.1241D, Cat. J/MNRAS/437/1241).

Ahumada & Lapasset (2007)
Each one of the five blue stragglers has a membership probability of 99% according to (1998A&AS..133..387B). Stars 2020, 2072, 2090, and 2110 are cited as blue stragglers in (1977AJ.....82..612H).

Data

🔍 Search references for NGC 1817 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–	78.145	16.699	0.568	0.428	-0.929	65.739
Otto et al.	2026	78.141	16.693	–	0.48	-0.89	66.2
Li et al.	2025	78.139	16.696	0.551	0.485	-0.89	–
Hu & Soubiran	2025	78.134	16.698	–	–	–	–
Wei et al.	2025	78.137	16.7	0.572	0.436	-0.951	–
Carrasco-Varela et al.	2025	78.379	16.683	–	–	–	–
Almeida et al.	2025	78.132	16.702	–	–	–	–
Zhang et al.	2024	78.141	16.693	–	–	–	–
Hunt & Reffert	2024	78.141	16.693	0.573	0.43	-0.932	66.742
Cavallo et al.	2024	78.134	16.697	0.572	–	–	–
Hunt & Reffert	2023	78.141	16.693	0.573	0.43	-0.932	66.742
Angelo et al.	2023	78.158	16.694	–	0.43	-0.93	–
Cordoni et al.	2023	78.132	16.702	0.553	0.504	-0.88	–
Just et al.	2023	78.075	16.68	–	–	–	–
Jadhav & Subramaniam	2021	78.139	16.696	–	–	–	–
Jaehnig et al.	2021	78.136	16.686	0.582	0.482	-0.883	–
Rain et al.	2021	78.139	16.696	0.551	0.485	-0.89	–
Dias et al.	2021	78.132	16.702	0.553	0.504	-0.88	65.554
Spina et al.	2021	78.137	16.696	0.553	0.493	-0.882	–
Cantat-Gaudin et al.	2020	78.139	16.696	0.551	0.485	-0.89	–
Zhong et al.	2020	78.139	16.696	–	0.485	-0.89	58.44
Cantat-Gaudin & Anders	2020	78.139	16.696	0.551	0.485	-0.89	–
Liu & Pang	2019	78.138	16.71	0.549	0.516	-0.888	–
Soubiran et al.	2018	78.139	16.696	–	–	–	66.07
Bica et al.	2019	78.116	16.696	–	–	–	–
Cantat-Gaudin et al.	2018	78.139	16.696	0.551	0.485	-0.89	–
Loktin & Popova	2017	78.06	16.691	–	0.084	-0.323	65.3
Kharchenko et al.	2016	78.075	16.68	–	–	–	–
Dias et al.	2014	78.062	16.69	–	-1.79	-2.17	–
Kharchenko et al.	2013	78.082	16.68	–	1.0	-1.6	65.3
Gozha et al.	2012	78.063	16.69	–	–	–	–
Bukowiecki et al.	2011	78.079	16.683	–	–	–	–
Piskunov et al.	2008	78.056	16.693	–	–	–	–
Kharchenko et al.	2007	78.06	16.69	–	0.23	–	–
Piskunov et al.	2007	78.056	16.693	–	–	–	–
Ahumada & Lapasset	2007	78.05	16.683	–	–	–	–
van den Bergh	2006	78.05	16.683	–	–	–	–
Kharchenko et al.	2005	78.06	16.69	–	-0.06	-3.13	–
Kharchenko et al.	2003	78.03	16.69	–	1.47	-3.37	–
Chen et al.	2003	78.027	16.698	–	–	–	–
Dias et al.	2002	78.062	16.69	–	-1.79	-2.17	65.31
Lynga	1987	78.018	16.692	–	–	–	–
Sulentic et al.	1973	78.011	16.696	–	–	–	–

💡 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–	1.72	1.03	0.51	1122	-0.142	1552	0.305	1
Otto et al.	2026	–	–	–	1122	-0.140⁽¹⁵⁾	–	–	–
Li et al.	2025	1.62	0.75	–	1195	-0.154	–	–	–
Hu & Soubiran	2025	–	–	–	–	-0.230⁽⁵⁾	–	–	–
Wei et al.	2025	1.97	0.66	–	1180	0.250	2304	0.39	–
Carrasco-Varela et al.	2025	1.58	0.72	–	1236	-0.100	–	–	1⁽¹⁾
Almeida et al.	2025	1.58	0.72	–	1236	–	1489	–	–
Zhang et al.	2024	–	–	–	–	-0.170⁽¹⁾	–	–	–
Hunt & Reffert	2024	–	–	–	–	–	2713⁽¹⁾	–	–
Cavallo et al.	2024	1.64	0.65	–	1175	0.120	–	–	–
Hunt & Reffert	2023	1.63	0.34	0.51	1330	–	–	–	–
Angelo et al.	2023	1.55	0.73	–	1122	-0.060	6⁽¹⁾	–	–
Cordoni et al.	2023	1.58	0.72	–	1236	-0.100	1904	0.22	1⁽¹⁾
Just et al.	2023	–	–	–	794	–	290	–	–
Spina et al.	2022	–	–	–	–	-0.140	–	–	–
Jadhav & Subramaniam	2021	1.80	0.59	–	1122	–	2574	–	1⁽¹⁾
Jaehnig et al.	2021	1.70⁽¹⁾	–	–	–	–	–	–	–
Rain et al.	2021	1.72	1.04	–	407	–	–	–	3
Dias et al.	2021	1.58	0.72	–	1236	-0.100	–	–	–
Spina et al.	2021	1.82	–	–	1122	-0.142⁽²⁰⁾	–	–	–
Cantat-Gaudin et al.	2020	1.80	0.59	–	1122	–	–	–	–
Kounkel et al.	2020	1.70	0.80	–	1175	–	–	–	–
Zhong et al.	2020	1.72⁽¹⁾	1.12	–	8900	-0.241	–	–	–
Cantat-Gaudin & Anders	2020	1.72	–	–	–	–	–	–	–
Liu & Pang	2019	–	–	–	1410	-0.250	–	–	–
Soubiran et al.	2018	1.72	–	–	–	–	–	–	–
Cantat-Gaudin et al.	2018	1.72	–	–	–	–	–	–	–
Loktin & Popova	2017	2.00	1.03	–	430	–	–	–	–
Kharchenko et al.	2016	1.50	1.12	–	794	–	–	–	–
Kharchenko et al.	2013	1.50	1.12	–	794	-0.140	–	–	–
Bukowiecki et al.	2012	–	–	–	–	–	403	–	–
Gozha et al.	2012	1.97	–	–	409	-0.230	1738	–	–
Bukowiecki et al.	2011	1.50⁽¹⁾	0.60	–	1000	–	–	–	–
Piskunov et al.	2008	1.97	1.04	–	178	–	1552⁽¹⁾	–	–
Piskunov et al.	2007	1.97	1.04	–	178	–	327	–	–
Ahumada & Lapasset	2007	–	1.04	–	407	–	–	–	5
van den Bergh	2006	1.97	1.04	–	407	–	–	–	–
Kharchenko et al.	2005	1.97	1.04	–	178	–	–	–	–
Kharchenko et al.	2003	1.96	1.04	–	–	–	–	–	–
Chen et al.	2003	1.97	1.05	–	400	-0.260⁽¹⁾	–	–	–
Dias et al.	2002	1.97	1.05	–	409	-0.160	–	–	–
Lynga	1987	1.75	1.04	–	794	-0.260	–	–	–

(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 1807	2.9	77.79	16.55	0.54	0.45	-0.94	65.36	0.22

💡 Note: The % column shows the percentage of members that NGC 1817 shares with each listed object.

Visualization

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