Hogg 21
(MWSC 2455)
0.95
UTI
0.76
CN
1.0
Cdens
1.0
CC3
1.0
Clit
1.0
Cdup
Radius (P>50% members)
5.0 [arcmin]
- CN 0.76 Rich
- Cdens 1.0 Very dense
- CC3 1.0 Very high quality
- Clit 1.0 Very well-studied
- Cdup 1.0 Unique
Overview
Hogg 21 is a rich, very dense object of very high C3 quality. Its parallax locates it at a moderate distance, near the mid-plane, affected by moderate extinction. It is catalogued as a near-solar metallicity, young cluster, but with a large variance across recent sources for the age and mass parameters (see Parameters). It is very well-studied in the literature.
Note: This object shares a very small percentage of members with a later reported entry. See table with shared members information.
Relatively close
Moderate extinction
Near-solar metallicity
Young
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | β | 251.407 | -47.742 | 0.37 | -0.969 | -2.173 | -43.908 |
| Li et al. | 2025 | 251.414 | -47.747 | 0.366 | -0.937 | -2.206 | β |
| Almeida et al. | 2025 | 251.405 | -47.747 | β | β | β | β |
| Hunt & Reffert | 2024 | 251.414 | -47.744 | 0.375 | -1.009 | -2.147 | -46.992 |
| Cavallo et al. | 2024 | 251.413 | -47.749 | 0.374 | β | β | β |
| Hunt & Reffert | 2023 | 251.414 | -47.744 | 0.375 | -1.009 | -2.147 | -46.992 |
| Just et al. | 2023 | 251.389 | -47.747 | β | β | β | β |
| Dias et al. | 2021 | 251.405 | -47.747 | 0.377 | -0.96 | -2.207 | -2.217 |
| Cantat-Gaudin et al. | 2020 | 251.414 | -47.747 | 0.366 | -0.937 | -2.206 | β |
| SΓ‘nchez et al. | 2020 | 251.404 | -47.733 | β | -1.286 | -2.024 | β |
| Cantat-Gaudin & Anders | 2020 | 251.414 | -47.747 | 0.366 | -0.937 | -2.206 | β |
| Dias et al. | 2019 | 251.404 | -47.733 | 0.347 | -0.96 | -2.174 | -41.031 |
| Soubiran et al. | 2018 | 251.414 | -47.747 | β | β | β | -2.75 |
| Cantat-Gaudin et al. | 2018 | 251.414 | -47.747 | 0.366 | -0.937 | -2.206 | β |
| Kharchenko et al. | 2016 | 251.389 | -47.747 | β | β | β | β |
| Dias et al. | 2014 | 251.404 | -47.733 | β | -0.35 | -3.07 | β |
| Kharchenko et al. | 2013 | 251.4 | -47.747 | β | -3.25 | -3.02 | β |
| Dias et al. | 2002 | 251.404 | -47.733 | β | -0.35 | -3.07 | β |
π‘ 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 | 2.06 | 1.68 | β | 343 | 0.060 | β | β | β |
| Almeida et al. | 2025 | 2.31 | 1.94 | β | 58 | β | 335 | β | β |
| Hunt & Reffert | 2024 | β | β | β | β | β | 772* | β | β |
| Cavallo et al. | 2024 | 2.23 | 2.00 | β | 141 | 0.040 | β | β | β |
| Hunt & Reffert | 2023 | 2.57 | 1.82 | 1.04 | 94 | β | β | β | β |
| Just et al. | 2023 | β | β | β | 28 | β | 69 | β | β |
| Dias et al. | 2021 | 2.31 | 1.94 | β | 58 | 0.169 | β | β | β |
| Cantat-Gaudin et al. | 2020 | 2.70 | 1.54 | β | 89 | β | β | β | β |
| Cantat-Gaudin & Anders | 2020 | 2.53 | β | β | β | β | β | β | β |
| Dias et al. | 2019 | 2.64 | 1.55 | β | 42 | 0.414 | β | β | β |
| Soubiran et al. | 2018 | 2.53 | β | β | β | β | β | β | β |
| Cantat-Gaudin et al. | 2018 | 2.53 | β | β | β | β | β | β | β |
| Kharchenko et al. | 2016 | 1.75 | 2.26 | β | 28 | β | β | β | β |
| Kharchenko et al. | 2013 | 1.75 | 2.26 | β | 28 | β | β | β | β |
| Dias et al. | 2002 | 1.75 | 2.26 | β | 28 | β | β | β | β |
(*): Indicates that this parameter is assigned more than one value in the corresponding reference.
Almeida et al. (2025)
Mass determination: intermediate fit. Isochrone match: good fit. Silver sample.
Cavallo et al. (2024)
Gold sample.