21019+5704
- Unique Name: 21019+5704BU 1139
- RA: 21 01 55.01
- Dec: +57 04 18.7
- Discoverer: BU
- Discoverer Number: 1139
- Components:
- First year: 1889
- Last year: 1965
- Observations: 5
- First position angle: 139
- Last position angle: 143
- First separation: 1.9
- Last separation: 1.6
- Mag first component: 6.69
- Mag second component: 12.5
- Spectral type: B8V
- Primary proper motion RA: 3
- Primary proper motion DEC: 4
- Secondary proper motion RA:
- Secondary proper motion DEC:
- Durchmusterung: +56 2523
- Notes: