21457+2100
- Unique Name: 21457+2100UC 4553
- RA: 21 45 42.63
- Dec: +21 00 22.0
- Discoverer: UC
- Discoverer Number: 4553
- Components:
- First year: 1999
- Last year: 2001
- Observations: 2
- First position angle: 185
- Last position angle: 185
- First separation: 60.3
- Last separation: 60.1
- Mag first component: 15.4
- Mag second component: 16.1
- Spectral type:
- Primary proper motion RA: -2
- Primary proper motion DEC: -86
- Secondary proper motion RA: -19
- Secondary proper motion DEC: -62
- Durchmusterung:
- Notes: V
