21023+3931
- Unique Name: 21023+3931SMY 6AE
- RA: 21 02 20.96
- Dec: +39 30 32.5
- Discoverer: SMY
- Discoverer Number: 6
- Components: AE
- First year: 1862
- Last year: 2012
- Observations: 8
- First position angle: 87
- Last position angle: 87
- First separation: 98.9
- Last separation: 97.0
- Mag first component: 6.62
- Mag second component: 10.88
- Spectral type: K3II-III
- Primary proper motion RA: 2
- Primary proper motion DEC: 1
- Secondary proper motion RA: -3
- Secondary proper motion DEC: -6
- Durchmusterung:
- Notes: N
