21008+3940
- Unique Name: 21008+3940SEI1364
- RA: 21 00 46.14
- Dec: +39 39 30.6
- Discoverer: SEI
- Discoverer Number: 1364
- Components:
- First year: 1892
- Last year: 2002
- Observations: 5
- First position angle: 117
- Last position angle: 114
- First separation: 11.8
- Last separation: 12.1
- Mag first component: 11.21
- Mag second component: 12.4
- Spectral type:
- Primary proper motion RA: -1
- Primary proper motion DEC: -19
- Secondary proper motion RA: 2
- Secondary proper motion DEC: -21
- Durchmusterung: +39 4404
- Notes: N
