21487+4357
- Unique Name: 21487+4357GRV 509
- RA: 21 48 44.75
- Dec: +43 57 54.4
- Discoverer: GRV
- Discoverer Number: 509
- Components:
- First year: 2000
- Last year: 2002
- Observations: 3
- First position angle: 177
- Last position angle: 177
- First separation: 56.5
- Last separation: 56.5
- Mag first component: 9.67
- Mag second component: 13.79
- Spectral type:
- Primary proper motion RA: -31
- Primary proper motion DEC: -19
- Secondary proper motion RA: -6
- Secondary proper motion DEC: -14
- Durchmusterung: +43 4052
- Notes: