21173+5837
- Unique Name: 21173+5837BU 1140AB
- RA: 21 17 18.79
- Dec: +58 36 41.4
- Discoverer: BU
- Discoverer Number: 1140
- Components: AB
- First year: 1889
- Last year: 1989
- Observations: 8
- First position angle: 277
- Last position angle: 274
- First separation: 3.9
- Last separation: 4.0
- Mag first component: 6.4
- Mag second component: 12.0
- Spectral type: B3III
- Primary proper motion RA: -3
- Primary proper motion DEC: 5
- Secondary proper motion RA:
- Secondary proper motion DEC:
- Durchmusterung: +57 2309
- Notes: N
