21490+4254
- Unique Name: 21490+4254TDT3172
- RA: 21 48 57.78
- Dec: +42 54 14.9
- Discoverer: TDT
- Discoverer Number: 3172
- Components:
- First year: 1991
- Last year: 1991
- Observations: 1
- First position angle: 164
- Last position angle: 164
- First separation: 0.4
- Last separation: 0.4
- Mag first component: 10.51
- Mag second component: 10.54
- Spectral type:
- Primary proper motion RA: -36
- Primary proper motion DEC: -98
- Secondary proper motion RA: -36
- Secondary proper motion DEC: -98
- Durchmusterung:
- Notes: