21045+5904
- Unique Name: 21045+5904MLB1090
- RA: 21 04 27.55
- Dec: +59 04 21.0
- Discoverer: MLB
- Discoverer Number: 1090
- Components:
- First year: 1918
- Last year: 2003
- Observations: 6
- First position angle: 30
- Last position angle: 33
- First separation: 9.8
- Last separation: 9.6
- Mag first component: 10.18
- Mag second component: 12.76
- Spectral type: B8
- Primary proper motion RA: -5
- Primary proper motion DEC: -4
- Secondary proper motion RA: 6
- Secondary proper motion DEC: -8
- Durchmusterung: +58 2220
- Notes: