21426+4103
- Unique Name: 21426+4103BU 688AB
- RA: 21 42 33.41
- Dec: +41 02 51.0
- Discoverer: BU
- Discoverer Number: 688
- Components: AB
- First year: 1877
- Last year: 2008
- Observations: 73
- First position angle: 209
- Last position angle: 200
- First separation: 0.3
- Last separation: 0.4
- Mag first component: 8.1
- Mag second component: 8.62
- Spectral type: F2V
- Primary proper motion RA: 26
- Primary proper motion DEC: -1
- Secondary proper motion RA: 26
- Secondary proper motion DEC: -1
- Durchmusterung: +40 4617
- Notes: NO
