21055+5340
- Unique Name: 21055+5340BU 680AB
- RA: 21 05 30.82
- Dec: +53 40 05.5
- Discoverer: BU
- Discoverer Number: 680
- Components: AB
- First year: 1877
- Last year: 2008
- Observations: 39
- First position angle: 311
- Last position angle: 284
- First separation: 0.5
- Last separation: 0.6
- Mag first component: 8.7
- Mag second component: 9.38
- Spectral type: A0
- Primary proper motion RA: 7
- Primary proper motion DEC: 8
- Secondary proper motion RA: 7
- Secondary proper motion DEC: 8
- Durchmusterung: +53 2546
- Notes: