21520+5548
- Unique Name: 21520+5548STF2840AB
- RA: 21 52 01.02
- Dec: +55 47 48.3
- Discoverer: STF
- Discoverer Number: 2840
- Components: AB
- First year: 1782
- Last year: 2012
- Observations: 102
- First position angle: 192
- Last position angle: 196
- First separation: 21.2
- Last separation: 17.7
- Mag first component: 5.64
- Mag second component: 6.42
- Spectral type: B6IV-V
- Primary proper motion RA: 19
- Primary proper motion DEC: -1
- Secondary proper motion RA: 13
- Secondary proper motion DEC: 13
- Durchmusterung: +55 2639
- Notes: NLD
