21139+0427
- Unique Name: 21139+0427BAL2977
- RA: 21 13 53.57
- Dec: +04 27 12.5
- Discoverer: BAL
- Discoverer Number: 2977
- Components:
- First year: 1908
- Last year: 2000
- Observations: 7
- First position angle: 292
- Last position angle: 303
- First separation: 16.8
- Last separation: 17.1
- Mag first component: 11.12
- Mag second component: 11.48
- Spectral type: G0
- Primary proper motion RA: -8
- Primary proper motion DEC: -27
- Secondary proper motion RA: 8
- Secondary proper motion DEC: 6
- Durchmusterung: +03 4525
- Notes: