21172+3936
- Unique Name: 21172+3936SEI1490AB
- RA: 21 17 12.97
- Dec: +39 36 27.4
- Discoverer: SEI
- Discoverer Number: 1490
- Components: AB
- First year: 1895
- Last year: 2002
- Observations: 5
- First position angle: 110
- Last position angle: 97
- First separation: 22.7
- Last separation: 20.3
- Mag first component: 11.42
- Mag second component: 12.44
- Spectral type:
- Primary proper motion RA: 21
- Primary proper motion DEC: -50
- Secondary proper motion RA: 12
- Secondary proper motion DEC: 1
- Durchmusterung:
- Notes: