NGC 6819

(Melotte 223; Collinder 403; MWSC 3155; OCL 155; FSR 0202; FoF 628)

Click to load Aladin Lite
1.0 UTI
1.0
CN
1.0
Cdens
1.0
CC3
1.0
Clit
1.0
Cdup
N50 (P>50% members) 2007
Stellar density (N50/rad) 143.4 [N/pc2]
C3 classification AA
  • CN 1.0 Very rich
  • Cdens 1.0 Very dense
  • CC3 1.0 Very high quality
  • Clit 1.0 Very well-studied
  • Cdup 1.0 Unique
πŸ“₯ Members πŸ“Š Colab πŸ”¬ Bayestar19 MOCAMOCA πŸ” CDS πŸ” Simbad πŸ” CDS (Ξ±, Ξ΄) πŸ” Simbad (Ξ±, Ξ΄)

Overview
ℹ️
NGC 6819 is a very rich, very dense object of very high C3 quality. Its parallax locates it at a moderate distance, above the mid-plane, affected by low extinction. It is catalogued as a very 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.

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

Cavallo et al. (2024)
Gold sample.

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

Rain et al. (2024)
The BSS population splits into two luminosity groups. Brighter BSSs are reproduced by binary evolution with higher-mass donors, while fainter ones follow lower-mass donor tracks. Overall agreement between models and observations is excellent, with some BSSs nearing MS turnoff.

Rain et al. (2021)
This object probably suffers from differential reddening. We suggest exploring this effect in future works.

Ahumada & Lapasset (2007)
The apparent cluster diameter is from (1970PDDO....4....1H). Several stragglers are pointed out in (1974A&AS...13..143A). Membership probabilities from (1972A&A....19..155S): star 32, 88%; star 35, 90%; star 36, 92%; star 40, 81%; star 55, 66%; star 59, 86%; star 65, 89%; star 70, 92%; star 96, 49%; star 103, 57%; star 118, 77%; star 6044, 33%. Attention is drawn in (1998AJ....115.1516R) on several clump stars that appear to be more massive than the turnoff stars: it is suggested that they are the descendants of blue stragglers.

Data
πŸ” Search references for NGC 6819 in: SciX Simbad
ℹ️
Reference Year RA [deg] DEC [deg] Plx [mas] pmRA [mas/yr] pmDE [mas/yr] Rv [km/s]
UCC 99999– 295.327 40.191 0.373 -2.894 -3.864 2.992
Bijavara Seshashayana et al. 2025 295.382 40.282 – – – –
Otto et al. 2026 295.322 40.19 – -2.92 -3.86 2.6
Nizovkina et al. 2025 295.322 40.19 – – – –
Li et al. 2025 295.327 40.19 0.356 -2.916 -3.856 –
Guerco et al. 2025 295.0 40.2 0.38 -2.85 -3.94 2.76
Hu & Soubiran 2025 295.326 40.192 – – – –
Wei et al. 2025 295.325 40.192 0.376 -2.893 -3.87 –
Carrasco-Varela et al. 2025 295.494 40.214 – – – –
Almeida et al. 2025 295.329 40.19 – – – –
Zhang et al. 2024 295.322 40.19 – – – –
Hunt & Reffert 2024 295.322 40.19 0.376 -2.9 -3.87 2.969
Cavallo et al. 2024 295.326 40.192 0.376 – – –
Rain et al. 2024 295.328 40.19 0.373 -2.894 -3.869 –
Hunt & Reffert 2023 295.322 40.19 0.376 -2.9 -3.87 2.969
Angelo et al. 2023 295.337 40.208 – -2.89 -3.87 –
Cordoni et al. 2023 295.329 40.19 0.357 -2.913 -3.856 –
Just et al. 2023 295.316 40.193 – – – –
Jadhav & Subramaniam 2021 295.327 40.19 – – – –
Jaehnig et al. 2021 295.324 40.192 0.384 -2.916 -3.858 –
Rain et al. 2021 295.327 40.19 0.356 -2.916 -3.856 –
Dias et al. 2021 295.329 40.19 0.357 -2.913 -3.856 3.376
Spina et al. 2021 295.327 40.19 0.357 -2.909 -3.857 –
Cantat-Gaudin et al. 2020 295.327 40.19 0.356 -2.916 -3.856 –
SΓ‘nchez et al. 2020 295.317 40.197 – -2.893 -3.727 –
Donor et al. 2020 295.32 40.195 – -2.96 -3.87 2.7
Zhong et al. 2020 295.327 40.19 – -2.916 -3.856 -4.191
Cantat-Gaudin & Anders 2020 295.327 40.19 0.356 -2.916 -3.856 –
Liu & Pang 2019 295.329 40.191 0.357 -2.908 -3.865 –
Bossini et al. 2019 295.327 40.19 – – – –
Soubiran et al. 2018 295.327 40.19 – – – 3.31
Bica et al. 2019 295.333 40.175 – – – –
Cantat-Gaudin et al. 2018 295.327 40.19 0.356 -2.916 -3.856 –
Loktin & Popova 2017 295.32 40.195 – -3.191 -0.848 1.0
Kharchenko et al. 2016 295.316 40.193 – – – –
Dias et al. 2014 295.317 40.197 – -6.07 -3.57 –
Kharchenko et al. 2013 295.32 40.195 – -3.99 -0.3 1.0
Gozha et al. 2012 295.325 40.187 – – – –
Bukowiecki et al. 2011 295.312 40.199 – – – –
Kharchenko et al. 2007 295.32 40.19 – 0.04 – –
Ahumada & Lapasset 2007 295.325 40.183 – – – –
van den Bergh 2006 295.325 40.187 – – – –
Chen et al. 2003 295.319 40.197 – -3.14 -3.34 4.8
Dias et al. 2002 295.317 40.197 – -6.07 -3.57 2.3
Lynga 1987 295.339 40.183 – – – –
Sulentic et al. 1973 295.339 40.193 – – – –

πŸ’‘ 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] Bfrac BSS
UCC 99999– 2.44 0.5 0.59 2239 0.050 7568 0.31 15
Bijavara Seshashayana et al. 2025 – 0.40 – 2240 -0.020(14) – – –
Otto et al. 2026 – – – 2239 0.040(15) – – –
Nizovkina et al. 2025 2.28(4) 0.60(4) – 2667(4) -0.108(4) – – –
Li et al. 2025 2.43 0.50 – 2583 0.056 – – –
Guerco et al. 2025 – – – 2240 0.040 – – –
Hu & Soubiran 2025 – – – – -0.100(5) – – –
Wei et al. 2025 2.06 0.22 – 3800 0.250 8717 0.58 –
Carrasco-Varela et al. 2025 2.44 0.49 – 2630 0.050 – – 14(1)
Almeida et al. 2025 2.44 0.49 – 2630 – 7277 – –
Zhang et al. 2024 – – – – 0.009(1) – – –
Hunt & Reffert 2024 – – – – – 7568(1) – –
Cavallo et al. 2024 2.39 0.70 – 1995 0.000 – – –
Rain et al. 2024 2.13 0.39 – 4644 – 28157 0.18 –
Hunt & Reffert 2023 2.52 0.32 0.59 1683 – – – –
Angelo et al. 2023 2.40 0.50 – 2512 0.100 24(1) – –
Cordoni et al. 2023 2.44 0.49 – 2630 0.093 4061 0.31 15(1)
Just et al. 2023 – – – 1622 – 843 – –
Spina et al. 2022 – – – – 0.050 – – –
Jadhav & Subramaniam 2021 2.77 0.40 – 2239 – 14963 – 12(1)
Jaehnig et al. 2021 2.61(1) – – – – – – –
Rain et al. 2021 2.60 0.50 – 2291 – – – 15
Dias et al. 2021 2.44 0.49 – 2630 0.093 – – –
Spina et al. 2021 2.80 – – 2239 0.058(20) – – –
Cantat-Gaudin et al. 2020 2.77 0.40 – 2239 – – – –
Kounkel et al. 2020 2.70 0.53 – 1778 – – – –
Donor et al. 2020 – – – – 0.050 – – –
Zhong et al. 2020 2.60(1) 0.48 – 9301 0.037 – – –
Cantat-Gaudin & Anders 2020 2.60 – – – – – – –
Liu & Pang 2019 – – – 3890 0.250 – – –
Bossini et al. 2019 2.71 0.47 – 2000 0.000 – – –
Soubiran et al. 2018 2.60 – – – – – – –
Cantat-Gaudin et al. 2018 2.60 – – – – – – –
Loktin & Popova 2017 2.41 0.73 – 1524 – – – –
Kharchenko et al. 2016 2.36 0.75 – 1622 – – – –
Kharchenko et al. 2013 2.36 0.75 – 1622 0.090 – – –
Bukowiecki et al. 2012 – – – – – 8559 – –
Gozha et al. 2012 2.36 – – 1493 0.090 – – –
Bukowiecki et al. 2011 2.65(1) 0.22 – 1778 – – – –
Ahumada & Lapasset 2007 – 0.76 – 1479 – – – 29
van den Bergh 2006 2.36 0.76 – 1479 – – – –
Chen et al. 2003 2.36 0.75 – 1490 0.070(1) – – –
Dias et al. 2002 2.40 0.50 – 2291 -0.020 – – –
Lynga 1987 2.20 1.42 – 3467 -0.110 – – –

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

Visualization
ℹ️
NGC 6819 UCC
NGC 6819 HUNT23
NGC 6819 CANTAT20
Galactocentric position diagram