Trumpler 9

(Collinder 168; MWSC 1384; Harvard 2; OCL 663; ESO 494 05; FSR 1313; FoF 383)

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0.91 UTI
0.8
CN
1.0
Cdens
0.75
CC3
1.0
Clit
1.0
Cdup
C3 classification AB
Number of members (P>50%) 242
Radius (P>50% members) 2.7 [arcmin]
  • CN 0.8 Rich
  • Cdens 1.0 Very dense
  • CC3 0.75 High quality
  • Clit 1.0 Very well-studied
  • Cdup 1.0 Unique
πŸ“₯ Members πŸ“Š Colab πŸ”¬ Bayestar19 πŸ” CDS πŸ” Simbad πŸ” CDS (Ξ±, Ξ΄) πŸ” Simbad (Ξ±, Ξ΄)

Overview
ℹ️
Trumpler 9 is a rich, very dense object of high C3 quality. Its parallax locates it at a moderate distance, above the mid-plane, affected by low 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.

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

Relatively close Low extinction Near-solar metallicity Young Contains BSS

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

Cavallo et al. (2024)
Gold sample.

Data
πŸ” Search references for Trumpler 9 in: SciX Simbad
ℹ️
Reference Year RA [deg] DEC [deg] Plx [mas] pmRA [mas/yr] pmDE [mas/yr] Rv [km/s]
UCC – 118.911 -25.885 0.355 -3.374 3.075 47.194
Li et al. 2025 118.911 -25.888 0.339 -3.402 3.069 –
Almeida et al. 2025 118.915 -25.894 – – – –
Hunt & Reffert 2024 118.915 -25.883 0.367 -3.383 3.09 43.387
Cavallo et al. 2024 118.917 -25.892 0.367 – – –
Hunt & Reffert 2023 118.915 -25.883 0.367 -3.383 3.09 43.387
Just et al. 2023 118.915 -25.878 – – – –
Jaehnig et al. 2021 118.908 -25.884 0.365 -3.388 3.092 –
Rain et al. 2021 118.911 -25.888 0.339 -3.402 3.069 –
Dias et al. 2021 118.915 -25.894 0.344 -3.411 3.073 –
Cantat-Gaudin et al. 2020 118.911 -25.888 0.339 -3.402 3.069 –
SΓ‘nchez et al. 2020 118.917 -25.883 – -3.295 3.155 –
Cantat-Gaudin & Anders 2020 118.911 -25.888 0.339 -3.402 3.069 –
Liu & Pang 2019 118.91 -25.884 0.32 -3.339 3.072 –
Bossini et al. 2019 118.911 -25.888 – – – –
Bica et al. 2019 118.915 -25.87 – – – –
Cantat-Gaudin et al. 2018 118.911 -25.888 0.339 -3.402 3.069 –
Loktin & Popova 2017 118.92 -25.883 – -2.637 2.408 -16.4
Kharchenko et al. 2016 118.915 -25.878 – – – –
Dias et al. 2014 118.917 -25.883 – 0.02 2.04 –
Kharchenko et al. 2013 118.92 -25.88 – -2.39 1.75 -16.4
Gozha et al. 2012 118.917 -25.883 – – – –
Piskunov et al. 2008 118.921 -25.879 – – – –
van den Bergh 2006 118.925 -25.885 – – – –
Kharchenko et al. 2005 118.92 -25.88 – -1.85 0.89 –
Kharchenko et al. 2003 118.9 -25.88 – -1.65 2.52 –
Dias et al. 2002 118.917 -25.883 – -0.68 2.46 –

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] Bfr BSS
Li et al. 2025 2.39 0.76 – 80 -0.137 – – –
Almeida et al. 2025 2.38 0.85 – 74 – 530 – –
Hunt & Reffert 2024 – – – – – 810* – –
Cavallo et al. 2024 2.36 0.54 – 166 0.180 – – –
Hunt & Reffert 2023 2.49 0.69 0.70 100 – – – –
Just et al. 2023 – – – 63 – 29 – –
Jaehnig et al. 2021 2.72* – – – – – – –
Rain et al. 2021 2.72 0.74 – 100 – – – 1
Dias et al. 2021 2.38 0.85 – 74 -0.083 – – –
Cantat-Gaudin et al. 2020 2.56 0.73 – 32 – – – –
Cantat-Gaudin & Anders 2020 2.72 – – – – – – –
Liu & Pang 2019 – – – 50 0.250 – – –
Bossini et al. 2019 2.90 0.87 – 31 0.000 – – –
Cantat-Gaudin et al. 2018 2.72 – – – – – – –
Loktin & Popova 2017 2.32 0.74 – 101 – – – –
Kharchenko et al. 2016 2.29 0.58 – 63 – – – –
Kharchenko et al. 2013 2.29 0.58 – 63 – – – –
Gozha et al. 2012 2.29 – – 100 – 107 – –
Piskunov et al. 2008 2.29 0.59 – 98 – – – –
van den Bergh 2006 2.29 0.78 – 100 – – – –
Kharchenko et al. 2005 2.29 0.59 – 98 – – – –
Kharchenko et al. 2003 2.27 0.74 – – – – – –
Dias et al. 2002 2.29 0.77 – 100 – – – –

(*): Indicates that this parameter is assigned more than one value in the corresponding reference.

Visualization
ℹ️
Trumpler 9 UCC
Trumpler 9 HUNT23
Trumpler 9 CANTAT20
Galactocentric position diagram