21023+3931
- Unique Name: 21023+3931H 4 113AB
- RA: 21 02 20.96
- Dec: +39 30 32.5
- Discoverer: H 4
- Discoverer Number: 113
- Components: AB
- First year: 1783
- Last year: 2012
- Observations: 32
- First position angle: 300
- Last position angle: 299
- First separation: 18.7
- Last separation: 19.2
- Mag first component: 6.62
- Mag second component: 9.49
- Spectral type: K3II-III
- Primary proper motion RA: 2
- Primary proper motion DEC: 1
- Secondary proper motion RA: 1
- Secondary proper motion DEC: 0
- Durchmusterung: +38 4321
- Notes: N D
