21519+4221
- Unique Name: 21519+4221HO 172AB
- RA: 21 51 53.07
- Dec: +42 20 40.6
- Discoverer: HO
- Discoverer Number: 172
- Components: AB
- First year: 1886
- Last year: 2012
- Observations: 12
- First position angle: 88
- Last position angle: 82
- First separation: 10.5
- Last separation: 10.7
- Mag first component: 7.93
- Mag second component: 11.26
- Spectral type: G5
- Primary proper motion RA: -175
- Primary proper motion DEC: -306
- Secondary proper motion RA: -175
- Secondary proper motion DEC: -306
- Durchmusterung: +41 4291
- Notes: NV
