21009+4730
- Unique Name: 21009+4730BU 1290BD
- RA: 21 00 56.53
- Dec: +47 29 44.5
- Discoverer: BU
- Discoverer Number: 1290
- Components: BD
- First year: 1898
- Last year: 2000
- Observations: 2
- First position angle: 25
- Last position angle: 21
- First separation: 2.4
- Last separation: 2.5
- Mag first component: 10.65
- Mag second component: 15.0
- Spectral type:
- Primary proper motion RA: 41
- Primary proper motion DEC: 47
- Secondary proper motion RA:
- Secondary proper motion DEC:
- Durchmusterung:
- Notes: