21561+2420
- Unique Name: 21561+2420STT 454AB
- RA: 21 56 04.91
- Dec: +24 20 23.6
- Discoverer: STT
- Discoverer Number: 454
- Components: AB
- First year: 1843
- Last year: 2009
- Observations: 34
- First position angle: 278
- Last position angle: 278
- First separation: 6.8
- Last separation: 7.1
- Mag first component: 7.97
- Mag second component: 10.04
- Spectral type: A0
- Primary proper motion RA: 12
- Primary proper motion DEC: -12
- Secondary proper motion RA: 7
- Secondary proper motion DEC: -13
- Durchmusterung: +23 4428
- Notes: D
