21009+4730
- Unique Name: 21009+4730BU 1290AC
- RA: 21 00 56.09
- Dec: +47 29 37.3
- Discoverer: BU
- Discoverer Number: 1290
- Components: AC
- First year: 1898
- Last year: 2000
- Observations: 2
- First position angle: 271
- Last position angle: 267
- First separation: 3.1
- Last separation: 3.5
- Mag first component: 10.09
- Mag second component: 14.0
- Spectral type:
- Primary proper motion RA: 13
- Primary proper motion DEC: 13
- Secondary proper motion RA:
- Secondary proper motion DEC:
- Durchmusterung:
- Notes: