Trumpler 21
(Collinder 274; VDBH 148; MWSC 2131; OCL 903; vdBergh-Hagen 148; ESO 096 15; FoF 2099)
- CN 0.76 Rich
- Cdens 1.0 Very dense
- CC3 0.75 High quality
- Clit 1.0 Very well-studied
- Cdup 1.0 Unique
Overview
Trumpler 21 is a rich, very dense object of high C3 quality. Its parallax locates it at a relatively close distance, near the mid-plane. 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.
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | – | 203.057 | -62.787 | 0.736 | -4.708 | -2.258 | -13.411 |
| Almeida et al. | 2025 | 203.067 | -62.789 | – | – | – | – |
| Hunt & Reffert | 2024 | 203.055 | -62.781 | 0.726 | -4.719 | -2.267 | -14.672 |
| Cavallo et al. | 2024 | 203.048 | -62.791 | 0.731 | – | – | – |
| Hunt & Reffert | 2023 | 203.055 | -62.781 | 0.726 | -4.719 | -2.267 | -14.672 |
| Cordoni et al. | 2023 | 203.067 | -62.789 | 0.725 | -4.667 | -2.293 | – |
| Just et al. | 2023 | 203.043 | -62.797 | – | – | – | – |
| Jaehnig et al. | 2021 | 203.073 | -62.788 | 0.756 | -4.671 | -2.313 | – |
| Rain et al. | 2021 | 203.068 | -62.787 | 0.722 | -4.682 | -2.312 | – |
| Dias et al. | 2021 | 203.067 | -62.789 | 0.725 | -4.667 | -2.293 | – |
| Cantat-Gaudin et al. | 2020 | 203.068 | -62.787 | 0.722 | -4.682 | -2.312 | – |
| Liu & Pang | 2019 | 203.066 | -62.787 | 0.728 | -4.674 | -2.273 | – |
| Bossini et al. | 2019 | 203.068 | -62.787 | – | – | – | – |
| Bica et al. | 2019 | 203.043 | -62.784 | – | – | – | – |
| Cantat-Gaudin et al. | 2018 | 203.068 | -62.787 | 0.722 | -4.682 | -2.312 | – |
| Loktin & Popova | 2017 | 203.055 | -62.8 | – | -8.459 | -2.734 | -32.9 |
| Kharchenko et al. | 2016 | 203.043 | -62.797 | – | – | – | – |
| Kharchenko et al. | 2013 | 203.055 | -62.8 | – | -10.4 | -4.5 | -32.9 |
| Piskunov et al. | 2008 | 203.047 | -62.794 | – | – | – | – |
| Kharchenko et al. | 2005 | 203.05 | -62.8 | – | -10.41 | -4.77 | – |
| Kharchenko et al. | 2003 | 203.05 | -62.78 | – | -11.09 | -1.86 | – |
| Dias et al. | 2002 | 203.058 | -62.8 | – | -3.62 | -3.36 | – |
| Dambis | 1999 | 203.05 | -62.8 | – | – | – | – |
💡 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 |
|---|---|---|---|---|---|---|---|---|---|
| Almeida et al. | 2025 | 1.28 | 0.85 | – | 51 | – | 343 | – | – |
| Hunt & Reffert | 2024 | – | – | – | – | – | 528* | – | – |
| Cavallo et al. | 2024 | 1.14 | 1.02 | – | 69 | -0.450 | – | – | – |
| Hunt & Reffert | 2023 | 1.28 | 0.60 | 0.66 | 95 | – | – | – | – |
| Cordoni et al. | 2023 | 1.28 | 0.85 | – | 51 | 0.138 | 2163 | 0.33 | 0.00 |
| Just et al. | 2023 | – | – | – | 71 | – | 81 | – | – |
| Tarricq et al. | 2022 | 1.29 | – | – | 51 | – | – | – | – |
| Jaehnig et al. | 2021 | 1.33* | – | – | – | – | – | – | – |
| Rain et al. | 2021 | 1.33 | 0.71 | – | 49 | – | – | – | 0 |
| Dias et al. | 2021 | 1.28 | 0.85 | – | 51 | 0.138 | – | – | – |
| Cantat-Gaudin et al. | 2020 | 1.32 | 0.58 | – | 49 | – | – | – | – |
| Liu & Pang | 2019 | – | – | – | 33 | 0.500 | – | – | – |
| Bossini et al. | 2019 | 1.29 | 0.72 | – | 49 | 0.000 | – | – | – |
| Cantat-Gaudin et al. | 2018 | 1.33 | – | – | – | – | – | – | – |
| Loktin & Popova | 2017 | 1.32 | 0.58 | – | 54 | – | – | – | – |
| Kharchenko et al. | 2016 | 1.27 | 0.78 | – | 71 | – | – | – | – |
| Kharchenko et al. | 2013 | 1.27 | 0.78 | – | 71 | – | – | – | – |
| Piskunov et al. | 2008 | 1.31 | 0.56 | – | 58 | – | – | – | – |
| Kharchenko et al. | 2005 | 1.31 | 0.56 | – | 58 | – | – | – | – |
| Kharchenko et al. | 2003 | 1.26 | 0.62 | – | – | – | – | – | – |
| Dias et al. | 2002 | 1.26 | 0.61 | – | 50 | – | – | – | – |
| Dambis | 1999 | 1.13 | 0.67 | – | 40 | – | – | – | – |
💡 Note: The parameters are sometimes
transformed from their original values to match the format of the
columns shown here, see FAQ.
The columns DAv, Bfr, BSS correspond to differential
extinction, binary fraction, and blue stragglers, respectively.
BSS values can be listed as fractions or integers.
(*): indicates that this parameter is
assigned more than one value in the corresponding reference.
