21156-3927
- Unique Name: 21156-3927B 521BC
- RA: 21 15 35.16
- Dec: -39 28 07.6
- Discoverer: B
- Discoverer Number: 521
- Components: BC
- First year: 1927
- Last year: 1991
- Observations: 4
- First position angle: 45
- Last position angle: 35
- First separation: 0.6
- Last separation: 0.5
- Mag first component: 10.15
- Mag second component: 10.43
- Spectral type: G0
- Primary proper motion RA: 25
- Primary proper motion DEC: -20
- Secondary proper motion RA: 25
- Secondary proper motion DEC: -20
- Durchmusterung: -3914174
- Notes: