21257+4043
- Unique Name: 21257+4043COU2306
- RA: 21 25 44.20
- Dec: +40 43 43.3
- Discoverer: COU
- Discoverer Number: 2306
- Components:
- First year: 1985
- Last year: 1991
- Observations: 2
- First position angle: 21
- Last position angle: 10
- First separation: 0.6
- Last separation: 0.7
- Mag first component: 11.17
- Mag second component: 11.34
- Spectral type:
- Primary proper motion RA: 2
- Primary proper motion DEC: 4
- Secondary proper motion RA: 2
- Secondary proper motion DEC: 4
- Durchmusterung: +40 4519
- Notes: