21156+3715
- Unique Name: 21156+3715WAL 138AC
- RA: 21 15 34.01
- Dec: +37 15 08.5
- Discoverer: WAL
- Discoverer Number: 138
- Components: AC
- First year: 1896
- Last year: 2002
- Observations: 4
- First position angle: 29
- Last position angle: 29
- First separation: 58.1
- Last separation: 57.5
- Mag first component: 7.75
- Mag second component: 12.44
- Spectral type: B4V
- Primary proper motion RA: 1
- Primary proper motion DEC: -4
- Secondary proper motion RA: 0
- Secondary proper motion DEC: -4
- Durchmusterung:
- Notes: