Berkeley 26

(Biurakan 12; MWSC 994; OCL 520)

0.38 UTI

0.45

C_N

0.13

C_dens

0.38

C_C3

0.48

C_lit

1.0

C_dup

N_m (P>50%) 45

Core radius and density 2.5 [pc], 0.7 [pc^-2]

C3 classification BC

C_N 0.45 Poorly populated
C_dens 0.13 Very loose
C_C3 0.38 Low quality
C_lit 0.48 Poorly studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

MOCA 🔍 CDS 🔍 Simbad 🔍 CDS (α, δ) 🔍 Simbad (α, δ)

Overview

ℹ️

Berkeley 26 is a poorly populated, very loose object of low C3 quality. Its parallax locates it at a large distance, above the mid-plane, affected by moderate extinction. It is catalogued as a massive, metal-poor, old cluster, but with a large variance across recent sources for the age and mass parameters (see Parameters). It is poorly studied in the literature.

Note: This object contains blue stragglers according to at least one source.

Distant Moderate extinction Massive Metal-poor Old Contains BSS

Perren et al. (2022)
The cluster appears as a weak overdensity against the background field. The RDP gives a radius near 2', but the TO is diffuse due to scatter and BSS candidates, and the giant branch is even less prominent. ASteCA sets the TO at G=18.5, resulting in a distance of 4.6 kpc and an age of 8.6 Gyr. Piatti 2010 reports 4.3 kpc and 4 Gyr — the distances are close, but the age difference is substantial, likely because ASteCA sets the TO almost half a magnitude fainter due to a large binary fraction (~70%). WEBDA and MWSC give 4.3 and 2.7 kpc; MWSC assigns a very young age of ~0.5 Gyr. The OC02 distance of 12.5 kpc appears to be a database recording error.

Data

🔍 Search references for Berkeley 26 in: SciX Simbad

ℹ️

Reference	Year	RA [deg]	DEC [deg]	Plx [mas]	pmRA [mas/yr]	pmDE [mas/yr]	Rv [km/s]
UCC	99999–	102.573	5.73	0.171	0.064	0.406	70.255
Cui et al.	2025	102.572	5.729	0.18	0.06	0.42	–
He et al.	2023	102.573	5.727	0.179	0.063	0.422	66.57
Just et al.	2023	102.54	5.757	–	–	–	–
Perren et al.	2022	102.547	5.755	–	–	–	–
Bica et al.	2019	102.564	5.736	–	–	–	–
Dias et al.	2018	–	–	–	0.11	-2.89	–
Loktin & Popova	2017	102.57	5.751	–	-0.978	-0.908	68.0
Sampedro et al.	2017	102.575	5.75	–	–	–	–
Kharchenko et al.	2016	102.54	5.757	–	–	–	–
Netopil et al.	2016	102.547	5.755	–	–	–	–
Tadross	2014	102.575	5.75	–	–	–	–
Dias et al.	2014	102.575	5.75	–	2.7	-1.44	–
Kharchenko et al.	2013	102.547	5.755	–	-4.12	-2.98	–
Gozha et al.	2012	102.575	5.75	–	–	–	–
Bukowiecki et al.	2011	102.558	5.732	–	–	–	–
Dias et al.	2002	102.575	5.75	–	2.7	-1.44	68.0
Lynga	1987	102.568	5.771	–	–	–	–

💡 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]	B_frac	BSS
UCC	99999–	4.625	1.71	–	1882	-0.525	2368	0.78	20
Cui et al.	2025	–	2.00	–	4467	–	–	–	20⁽¹⁾
He et al.	2023	4.68	2.00	–	3981	–	–	–	–
Just et al.	2023	–	–	–	513	–	136	–	–
Perren et al.	2022	4.57	1.74	–	8710	0.070	4600	0.78	–
Loktin & Popova	2017	3.58	1.35	–	891	–	–	–	–
Kharchenko et al.	2016	2.72	1.71	–	513	–	–	–	–
Netopil et al.	2016	12.13	–	–	1770	–	–	–	–
Tadross	2014	2.72	1.70	–	600	–	–	–	–
Kharchenko et al.	2013	2.72	1.71	–	513	-0.700	–	–	–
Gozha et al.	2012	12.59	–	–	3981	-0.700	–	–	–
Bukowiecki et al.	2011	8.16⁽¹⁾	1.58	–	1995	–	–	–	–
Dias et al.	2002	12.59	2.37	–	3981	-0.350	–	–	–

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

Visualization

ℹ️