Registry · deep sky

M 21

OpenCluster SIMBAD OpC 158 papers

harvesting The full record is being pulled from the archives right now — measurement tables, the Gaia row, catalogue photometry. This page will fill itself in.

Right ascension: 18h 04m 08.60s
Declination: −22° 30′ 18.0″
Galactic l, b: 7.6559, -0.3474
Parallax: 0.798 mas
Redshift z: -6.077e-05
Radial velocity: -18.22 km/s
Proper motion: 0.525, -1.521 mas/yr
Angular size: 110′ × 110′

Also known as

10 identifiers

C 1801-225M 21NGC 6531OCISM 3OCl 26.0[SC95] M 248[SC96] GC 372[SC96] Mis 946[KPR2004b] 427[KPS2012] MWSC 2796

In the same field

within 9 arcmin · wider search

Object	Type	Separation	V
Cl* NGC 6531 F 27	YSO Candidate	13.19″	14.78
Gaia DR3 4069667162947245568	YSO Candidate	16.41″	—
Gaia DR3 4069667128575947136	YSO	34.82″	—
2MASS J18040690-2230476	Star	37.89″	—
HD 313693	Star	50.36″	9.13
Cl* NGC 6531 ZUG 57	YSO Candidate	54.27″	12.49
HD 164863	Star	57.93″	7.22
NGC 6531 16	YSO	64.67″	11.87
NGC 6531 23	YSO Candidate	68.19″	12.6
Cl* NGC 6531 F 2	YSO Candidate	68.24″	15.53
Gaia DR3 4069667025508291968	YSO Candidate	73.97″	—

Provenance

where this card came from

Archive	Read at (UTC)	Record
Seeded from the bulk archive load; no per-object fetch yet.

Machine-readable: /api/v1/object/m-21 · Registry entry updated 2026-08-14.