21057+4748
- Unique Name: 21057+4748BU 158
- RA: 21 05 43.99
- Dec: +47 48 17.0
- Discoverer: BU
- Discoverer Number: 158
- Components:
- First year: 1873
- Last year: 2003
- Observations: 13
- First position angle: 320
- Last position angle: 306
- First separation: 12.0
- Last separation: 11.3
- Mag first component: 7.45
- Mag second component: 12.0
- Spectral type: B9V
- Primary proper motion RA: 5
- Primary proper motion DEC: 3
- Secondary proper motion RA:
- Secondary proper motion DEC:
- Durchmusterung: +47 3284
- Notes: