21521+0739
- Unique Name: 21521+0739OSO 158AB
- RA: 21 52 08.91
- Dec: +07 38 40.1
- Discoverer: OSO
- Discoverer Number: 158
- Components: AB
- First year: 1994
- Last year: 2000
- Observations: 4
- First position angle: 111
- Last position angle: 114
- First separation: 14.0
- Last separation: 12.9
- Mag first component: 10.84
- Mag second component: 14.6
- Spectral type: G5
- Primary proper motion RA: 199
- Primary proper motion DEC: 43
- Secondary proper motion RA: -13
- Secondary proper motion DEC: -9
- Durchmusterung: +06 4914
- Notes: N
