HXHWL 18
(H21OC 18)
0.30
UTI
0.32
CN
0.07
Cdens
0.5
CC3
0.31
Clit
1.0
Cdup
Nm (P>50%)
32
Core radius and density
3.4 [pc], 0.4 [pc-2]
- CN 0.32 Poorly populated
- Cdens 0.07 Very loose
- CC3 0.5 Intermediate quality
- Clit 0.31 Poorly studied
- Cdup 1.0 Unique
đĨ Members
đ Colab
đŦ Bayestar19
MOCA
đ CDS
đ Simbad
đ CDS (Îą, δ)
đ Simbad (Îą, δ)
MOCA
đ CDS
đ Simbad
đ CDS (Îą, δ)
đ Simbad (Îą, δ)
Overview
HXHWL 18 is a poorly populated, very loose object of intermediate C3 quality. Its parallax locates it at a relatively close distance, near 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 absorption and metallicity parameters (see Parameters). It is poorly studied in the literature.
â ī¸ Warning: the low UTI value and no obvious signs of duplication (Cdup=1.0) indicate that this is quite probably an asterism, moving group, or artifact, and not a real open cluster.
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | 99999â | 74.284 | 39.575 | 0.957 | -0.456 | -3.099 | -9.207 |
| Liu et al. | 2025 | 74.32 | 39.8 | 0.96 | -0.53 | -3.06 | -9.6 |
| Zhang et al. | 2024 | 74.317 | 39.796 | â | â | â | â |
| Hunt & Reffert | 2024 | 74.317 | 39.796 | 0.956 | -0.53 | -3.058 | -9.6 |
| Cavallo et al. | 2024 | 74.31 | 39.6 | 0.958 | â | â | â |
| Hunt & Reffert | 2023 | 74.317 | 39.796 | 0.956 | -0.53 | -3.058 | -9.6 |
| He et al. | 2022 | 74.309 | 39.627 | 0.958 | -0.49 | -3.105 | â |
| He et al. | 2021 | 74.319 | 39.594 | 0.95 | -0.4 | -3.05 | â |
đĄ 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 | 99999â | 1.0 | 0.84 | 0.57 | 52 | 0.097 | 82 | â | â |
| Liu et al. | 2025 | 1.37 | 0.31 | â | 35 | â | â | â | â |
| Zhang et al. | 2024 | â | â | â | â | -0.142(1) | â | â | â |
| Hunt & Reffert | 2024 | 1.00 | 0.76 | 0.57 | 69 | â | 82(1) | â | â |
| Cavallo et al. | 2024 | 1.00 | 0.92 | â | 79 | 0.180 | â | â | â |
| Hunt & Reffert | 2023 | 1.00 | 0.76 | 0.57 | 69 | â | â | â | â |
| He et al. | 2022 | â | 1.15 | â | 32 | â | â | â | â |
| He et al. | 2021 | 0.95 | 1.14 | â | 35 | 0.097 | â | â | â |
(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.
Liu et al. (2025)
Classified as tidal capture (resonant trapping binary) 2 along with ASCC_12, and as primordial binary cluster 190 along with HSC_1308, and of multiple system 2 along with COIN-Gaia_10, COIN-Gaia_39, HSC_1308 and ASCC_12.
Palma et al. (2025)
Part of multiple system G110, along with COIN-Gaia_39, ASCC_12 and HSC_1308.
Cavallo et al. (2024)
Gold sample.
Hunt & Reffert (2024)
Classified as open cluster. CMD class: 1.00 (50th percentile).
Hunt & Reffert (2023)
Classified as open cluster. CMD class: 1.00 (50th percentile).