21090+0643
- Unique Name: 21090+0643STT 428
- RA: 21 08 59.63
- Dec: +06 43 24.5
- Discoverer: STT
- Discoverer Number: 428
- Components:
- First year: 1843
- Last year: 2013
- Observations: 26
- First position angle: 257
- Last position angle: 255
- First separation: 23.0
- Last separation: 24.4
- Mag first component: 8.41
- Mag second component: 9.93
- Spectral type: A5
- Primary proper motion RA: -5
- Primary proper motion DEC: 5
- Secondary proper motion RA: -46
- Secondary proper motion DEC: 8
- Durchmusterung: +06 4759
- Notes: