21105+4742
- Unique Name: 21105+4742STTA215AC
- RA: 21 10 30.96
- Dec: +47 41 32.0
- Discoverer: STT
- Discoverer Number: 0
- Components: AC
- First year: 1875
- Last year: 2012
- Observations: 21
- First position angle: 190
- Last position angle: 189
- First separation: 134.1
- Last separation: 136.7
- Mag first component: 6.55
- Mag second component: 7.52
- Spectral type: B6IV
- Primary proper motion RA: -4
- Primary proper motion DEC: -4
- Secondary proper motion RA: -5
- Secondary proper motion DEC: -18
- Durchmusterung: +47 3321
- Notes: N D
