21399+3931
- Unique Name: 21399+3931HJ 1675AC
- RA: 21 39 53.72
- Dec: +39 30 53.8
- Discoverer: HJ
- Discoverer Number: 1675
- Components: AC
- First year: 1951
- Last year: 2003
- Observations: 6
- First position angle: 263
- Last position angle: 263
- First separation: 35.1
- Last separation: 37.4
- Mag first component: 6.8
- Mag second component: 12.8
- Spectral type: A3
- Primary proper motion RA: 49
- Primary proper motion DEC: 6
- Secondary proper motion RA:
- Secondary proper motion DEC:
- Durchmusterung:
- Notes: U
