21591+3900
- Unique Name: 21591+3900MLB 789
- RA: 21 59 03.02
- Dec: +38 59 56.9
- Discoverer: MLB
- Discoverer Number: 789
- Components:
- First year: 1932
- Last year: 2006
- Observations: 4
- First position angle: 0
- Last position angle: 359
- First separation: 8.9
- Last separation: 10.0
- Mag first component: 12.6
- Mag second component: 13.1
- Spectral type:
- Primary proper motion RA: -2
- Primary proper motion DEC: -3
- Secondary proper motion RA: -4
- Secondary proper motion DEC: -7
- Durchmusterung:
- Notes: