Collinder 261
(VDBH 136; MWSC 2055; Harvard 6; OCL 889; vdBergh-Hagen 136; ESO 065 02; FSR 1627; FoF 45)
1.0
UTI
1.0
CN
1.0
Cdens
1.0
CC3
1.0
Clit
1.0
Cdup
N50 (P>50% members)
4192
Stellar density (N50/rad)
167.0 [N/pc2]
- CN 1.0 Very rich
- Cdens 1.0 Very dense
- CC3 1.0 Very high quality
- Clit 1.0 Very well-studied
- Cdup 1.0 Unique
π₯ Members
π Colab
π¬ Bayestar19
MOCA
π CDS
π Simbad
π CDS (Ξ±, Ξ΄)
π Simbad (Ξ±, Ξ΄)
MOCA
π CDS
π Simbad
π CDS (Ξ±, Ξ΄)
π Simbad (Ξ±, Ξ΄)
Overview
Collinder 261 is a very rich, very dense object of very high C3 quality. Its parallax locates it at a moderate distance, below the mid-plane, affected by low extinction. It is catalogued as an extremely massive, near-solar metallicity, very old cluster, but with a large variance across recent sources for the age, 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.
Note: This object shares a very small percentage of members with a later reported entry. See table with shared members information.
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | 99999β | 189.519 | -68.379 | 0.343 | -6.364 | -2.676 | -25.0 |
| Li et al. | 2025 | 189.519 | -68.377 | 0.315 | -6.351 | -2.705 | β |
| Hu & Soubiran | 2025 | 189.512 | -68.378 | β | β | β | β |
| Carrasco-Varela et al. | 2025 | 189.802 | -68.492 | β | β | β | β |
| Almeida et al. | 2025 | 189.512 | -68.378 | β | β | β | β |
| Hunt & Reffert | 2024 | 189.527 | -68.381 | 0.345 | -6.367 | -2.678 | -25.508 |
| Cavallo et al. | 2024 | 189.512 | -68.378 | 0.345 | β | β | β |
| Rain et al. | 2024 | 189.518 | -68.377 | 0.346 | -6.365 | -2.686 | β |
| Hunt & Reffert | 2023 | 189.527 | -68.381 | 0.345 | -6.367 | -2.678 | -25.508 |
| Just et al. | 2023 | 189.513 | -68.364 | β | β | β | β |
| Jaehnig et al. | 2021 | 189.525 | -68.376 | 0.346 | -6.344 | -2.714 | β |
| Rain et al. | 2021 | 189.519 | -68.377 | 0.315 | -6.351 | -2.705 | β |
| Dias et al. | 2021 | 189.512 | -68.378 | 0.314 | -6.344 | -2.702 | -24.654 |
| Cantat-Gaudin et al. | 2020 | 189.519 | -68.377 | 0.315 | -6.351 | -2.705 | β |
| SΓ‘nchez et al. | 2020 | 189.488 | -68.367 | β | -6.32 | -2.721 | β |
| Cantat-Gaudin & Anders | 2020 | 189.519 | -68.377 | 0.315 | -6.351 | -2.705 | β |
| Liu & Pang | 2019 | 189.513 | -68.383 | 0.331 | -6.344 | -2.694 | β |
| Soubiran et al. | 2018 | 189.519 | -68.377 | β | β | β | -24.67 |
| Bica et al. | 2019 | 189.477 | -68.369 | β | β | β | β |
| Cantat-Gaudin et al. | 2018 | 189.519 | -68.377 | 0.315 | -6.351 | -2.705 | β |
| Kharchenko et al. | 2016 | 189.513 | -68.364 | β | β | β | β |
| Dias et al. | 2014 | 189.487 | -68.367 | β | -0.65 | -0.51 | β |
| Kharchenko et al. | 2013 | 189.525 | -68.367 | β | -10.27 | 3.32 | -30.0 |
| Gozha et al. | 2012 | 189.488 | -68.367 | β | β | β | β |
| Kharchenko et al. | 2007 | 189.48 | -68.37 | β | 0.08 | β | β |
| van den Bergh | 2006 | 189.475 | -68.467 | β | β | β | β |
| Chen et al. | 2003 | 189.479 | -68.359 | β | β | β | β |
| Dias et al. | 2002 | 189.488 | -68.367 | β | -0.77 | -0.55 | -30.0 |
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] | Bfrac | BSS |
|---|---|---|---|---|---|---|---|---|---|
| UCC | 99999β | 2.74 | 1.0 | 1.27 | 7907 | -0.030 | 13424 | 0.37 | 0.23 |
| Li et al. | 2025 | 2.74 | 0.94 | β | 6646 | 0.042 | β | β | β |
| Hu & Soubiran | 2025 | β | β | β | β | -0.190(5) | β | β | β |
| Carrasco-Varela et al. | 2025 | 2.71 | 1.00 | β | 7907 | 0.100 | β | β | 0.23(1) |
| Almeida et al. | 2025 | 2.81 | 1.00 | β | 7907 | β | 17516 | β | β |
| Hunt & Reffert | 2024 | β | β | β | β | β | 9333(1) | β | β |
| Cavallo et al. | 2024 | 2.36 | 1.24 | β | 5754 | -0.250 | β | β | β |
| Rain et al. | 2024 | 2.57 | 1.00 | β | 8104 | β | 36941 | 0.37 | β |
| Hunt & Reffert | 2023 | 2.74 | 1.21 | 1.27 | 1995 | β | β | β | β |
| Just et al. | 2023 | β | β | β | 5012 | β | 2254 | β | β |
| Jaehnig et al. | 2021 | 2.88(1) | β | β | β | β | β | β | β |
| Rain et al. | 2021 | 2.90 | 0.84 | β | 8913 | β | β | β | 53 |
| Dias et al. | 2021 | 2.81 | 1.00 | β | 7907 | 0.019 | β | β | β |
| Cantat-Gaudin et al. | 2020 | 2.84 | 0.81 | β | 6310 | β | β | β | β |
| Cantat-Gaudin & Anders | 2020 | 2.90 | β | β | β | β | β | β | β |
| Liu & Pang | 2019 | β | β | β | 2630 | 0.500 | β | β | β |
| Soubiran et al. | 2018 | 2.90 | β | β | β | β | β | β | β |
| Cantat-Gaudin et al. | 2018 | 2.90 | β | β | β | β | β | β | β |
| Kharchenko et al. | 2016 | 2.68 | 1.03 | β | 5012 | β | β | β | β |
| Kharchenko et al. | 2013 | 2.68 | 1.03 | β | 5012 | -0.030 | β | β | β |
| Gozha et al. | 2012 | 2.19 | β | β | 8913 | -0.030 | β | β | β |
| van den Bergh | 2006 | 2.19 | 0.84 | β | 8913 | β | β | β | β |
| Chen et al. | 2003 | 2.19 | 0.84 | β | 8900 | -0.140(1) | β | β | β |
| Dias et al. | 2002 | 2.19 | 0.84 | β | 8913 | -0.030 | β | β | β |
(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.
Almeida et al. (2025)
Mass determination: good fit. Isochrone match: good fit. Gold sample.
Cavallo et al. (2024)
Gold sample.
Rain et al. (2024)
The cluster hosts a rich BSS population forming a nearly continuous sequence overlapping the ZAMS and binary tracks. A few objects lie below the turnoff and may be sub-subdwarfs or misidentifications. One bright candidate resembles a YSS but does not meet standard CMD criteria.