21510+5621
- Unique Name: 21510+5621KR 55AC
- RA: 21 51 00.59
- Dec: +56 21 19.3
- Discoverer: KR
- Discoverer Number: 55
- Components: AC
- First year: 1898
- Last year: 2011
- Observations: 12
- First position angle: 21
- Last position angle: 21
- First separation: 16.4
- Last separation: 15.9
- Mag first component: 10.31
- Mag second component: 11.63
- Spectral type: G5
- Primary proper motion RA: -8
- Primary proper motion DEC: -14
- Secondary proper motion RA: -4
- Secondary proper motion DEC: -1
- Durchmusterung:
- Notes: