NGC 1976

(Trapezium; Ori Trapezium; Trapezium-FG)

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0.75 UTI
0.6
CN
1.0
Cdens
0.62
CC3
0.77
Clit
1.0
Cdup
N50 (P>50% members) 69
Stellar density (N50/rad) 28.9 [N/pc2]
C3 classification AC
  • CN 0.6 Moderately populated
  • Cdens 1.0 Very dense
  • CC3 0.62 Intermediate quality
  • Clit 0.77 Well-studied
  • Cdup 1.0 Unique
đŸ“Ĩ Members 📊 Colab đŸ”Ŧ Bayestar19 MOCAMOCA 🔍 CDS 🔍 Simbad 🔍 CDS (Îą, δ) 🔍 Simbad (Îą, δ)

Overview
ℹī¸
NGC 1976 is a moderately populated, very dense object of intermediate C3 quality. Its parallax locates it at a very close distance, below the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, very young cluster, but with a large variance across recent sources for the metallicity and mass parameters (see Parameters). It is well-studied in the literature.

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

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

Ahumada & Lapasset (2007)
= Trapezium. The apparent cluster diameter was taken from (1970PDDO....4....1H). The colour-magnitude diagram of (1952ApJ...116..251S) was dereddened using the reddenings for each star listed in the reference. Star 1891 (WEBDA) = Theta1 Orionis A = HD 37022 (sp. O7Vp,v.sin i=140km/s, var?), appears blueward the ZAMS in the dereddened diagram, but it is a non-member according to (1983A&AS...54..221M).

Bica et al. (2003)
Classified as infrared cluster (IRC).

Lada & Lada (2003)
Embedded cluster within âˆŧ2 Kpc of the Sun.

Data
🔍 Search references for NGC 1976 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– 83.821 -5.452 2.579 1.254 0.19 19.859
Wei et al. 2025 83.823 -5.418 2.564 1.156 0.246 –
Almeida et al. 2025 83.835 -5.41 – – – –
Jaehnig et al. 2021 83.829 -5.417 2.57 1.276 0.176 –
Dias et al. 2021 83.835 -5.41 2.557 1.262 0.274 23.841
Dias et al. 2018 – – – 0.02 0.37 –
Dib et al. 2018 83.827 -5.36 – – – –
Loktin & Popova 2017 83.82 -5.39 – 2.05 1.56 28.9
Sampedro et al. 2017 83.817 -5.39 1.85 1.78 – –
Joshi et al. 2016 83.827 -5.36 – – – –
Dias et al. 2014 83.817 -5.39 – 2.05 1.56 –
Gozha et al. 2012 83.817 -5.39 – – – –
Bukowiecki et al. 2011 83.821 -5.385 – – – –
Piskunov et al. 2008 83.813 -5.392 – – – –
Kharchenko et al. 2007 83.82 -5.39 – 0.4 – 28.94
Piskunov et al. 2007 83.813 -5.392 – – – –
Ahumada & Lapasset 2007 83.825 -5.383 – – – –
van den Bergh 2006 83.822 -5.391 – – – –
Kharchenko et al. 2005 83.82 -5.39 – 1.96 -0.77 28.94
Lada & Lada 2003 84.448 -5.363 – – – –
Kharchenko et al. 2003 83.85 -5.38 – 2.02 -0.19 –
Bica et al. 2003 83.84 -5.378 – – – –
Dias et al. 2002 83.817 -5.39 – 2.05 1.56 31.98
Dambis 1999 83.822 -5.391 – – – –
Lynga 1987 83.831 -5.383 – – – 23.0
Sulentic et al. 1973 83.832 -5.385 – – – –

💡 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– 0.41 0.19 – 13 0.177 167 0.47 0
Wei et al. 2025 0.49 0.95 – 13 0.500 2585 0.47 –
Almeida et al. 2025 0.38 0.25 – 6 – 238 – –
Jaehnig et al. 2021 0.39(1) – – – – – – –
Dias et al. 2021 0.38 0.25 – 6 -0.146 – – –
Dib et al. 2018 0.46 – – 1 – – – –
Loktin & Popova 2017 0.49 0.98 – 10 – – – –
Joshi et al. 2016 0.46 0.92 – 1 – 98 – –
Gozha et al. 2012 0.41 – – 13 – 98 – –
Piskunov et al. 2008 0.40 0.16 – 51 – 167(1) – –
Piskunov et al. 2007 0.40 0.16 – 51 – 58 – –
Ahumada & Lapasset 2007 – 0.16 – 13 – – – 0
van den Bergh 2006 0.40 0.16 – 13 – – – –
Kharchenko et al. 2005 0.40 0.16 – 51 – – – –
Lada & Lada 2003 0.50 – – – – 413 – –
Kharchenko et al. 2003 0.45 0.19 – – – – – –
Dias et al. 2002 0.41 0.16 – 13 – – – –
Dambis 1999 0.36 0.19 – 3 – – – –
Lynga 1987 0.45 – – 25 – – – –

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

Cluster % RA DEC Plx pmRA pmDE Rv UTI
OCSN 225 73.9 83.84 -4.96 2.55 1.25 -0.08 22.73 0.36
UBC 208 47.8 83.81 -5.95 2.6 1.24 0.54 23.25 0.06
NGC 1980 42.0 83.82 -5.96 2.6 1.24 0.55 20.88 0.88
OCSN 244 39.1 83.82 -5.43 2.52 1.39 0.33 25.62 0.25
OCSN 226 36.2 83.82 -5.96 2.61 1.26 0.55 23.02 0.02
Orion Nebula 18.8 83.82 -5.36 2.51 1.23 0.18 25.16 0.34
OMC-1 17.4 83.82 -5.37 2.5 0.95 -0.07 -7.13 0.39
OC 0345 15.9 83.77 -5.87 2.58 1.06 0.21 19.86 0.03
OC 0347 11.6 83.99 -6.36 2.6 1.01 0.32 24.19 0.31
OMC-2 11.6 83.85 -5.17 2.54 1.04 -0.02 26.69 0.17
UBC 207 1.4 83.87 -4.61 2.57 1.11 0.57 20.54 0.49

💡 Note: The % column shows the percentage of members that NGC 1976 shares with each listed object.

Visualization
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NGC 1976 UCC
Galactocentric position diagram