FSR 1640

(MWSC 2089)

0.16 UTI

0.0

C_N

0.05

C_dens

0.12

C_C3

0.31

C_lit

1.0

C_dup

C3 classification DC

Number of members (P>50%) 22

Radius (P>50% members) 6.7 [arcmin]

C_N 0.0 Sparse
C_dens 0.05 Very loose
C_C3 0.12 Very low quality
C_lit 0.31 Poorly studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19 🔍 CDS 🔍 Simbad 🔍 CDS (α, δ) 🔍 Simbad (α, δ)

Overview

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FSR 1640 is a sparse, very loose object of very low C3 quality. Its parallax locates it at a moderate distance, well below the mid-plane, affected by low extinction. It is catalogued as an extremely massive, old cluster (see Parameters). It is poorly studied in the literature.

⚠️ Warning: the low UTI value and no obvious signs of duplication (C_dup=1.0) indicate that this is quite probably an asterism, moving group, or artifact, and not a real open cluster.

Very distant Low extinction Extremely massive Old

Data

🔍 Search references for FSR 1640 in: SciX Simbad

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Reference	Year	RA [deg]	DEC [deg]	Plx [mas]	pmRA [mas/yr]	pmDE [mas/yr]	Rv [km/s]
UCC	–	197.872	-77.465	0.216	-7.419	-0.442	-0.344
Just et al.	2023	197.959	-77.447	–	–	–	–
Bica et al.	2019	197.973	-77.436	–	–	–	–
Kharchenko et al.	2016	197.959	-77.447	–	–	–	–
Kharchenko et al.	2013	197.977	-77.45	–	-14.11	-0.42	–
Froebrich et al.	2007	197.992	-77.439	–	–	–	–

💡 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
Just et al.	2023	–	–	–	1585	–	10715	–	–
Kharchenko et al.	2016	6.21	0.32	–	1585	–	–	–	–
Kharchenko et al.	2013	6.21	0.32	–	1585	–	–	–	–

Visualization

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