21042+3924
- Unique Name: 21042+3924SEI1389
- RA: 21 04 09.78
- Dec: +39 23 44.9
- Discoverer: SEI
- Discoverer Number: 1389
- Components:
- First year: 1895
- Last year: 2002
- Observations: 3
- First position angle: 79
- Last position angle: 61
- First separation: 15.6
- Last separation: 18.2
- Mag first component: 11.0
- Mag second component: 11.0
- Spectral type:
- Primary proper motion RA: -9
- Primary proper motion DEC: -4
- Secondary proper motion RA: 8
- Secondary proper motion DEC: 2
- Durchmusterung:
- Notes: