21287+5710
- Unique Name: 21287+5710BU 1142
- RA: 21 28 41.72
- Dec: +57 09 33.7
- Discoverer: BU
- Discoverer Number: 1142
- Components:
- First year: 1889
- Last year: 2009
- Observations: 14
- First position angle: 354
- Last position angle: 3
- First separation: 0.4
- Last separation: 0.4
- Mag first component: 10.58
- Mag second component: 10.69
- Spectral type: F8
- Primary proper motion RA: 5
- Primary proper motion DEC: -4
- Secondary proper motion RA: 5
- Secondary proper motion DEC: -4
- Durchmusterung: +56 2579
- Notes: