21561+2420
- Unique Name: 21561+2420STT 454AC
- RA: 21 56 04.91
- Dec: +24 20 23.6
- Discoverer: STT
- Discoverer Number: 454
- Components: AC
- First year: 1891
- Last year: 2001
- Observations: 8
- First position angle: 265
- Last position angle: 264
- First separation: 42.9
- Last separation: 43.0
- Mag first component: 7.97
- Mag second component: 11.8
- Spectral type: A0
- Primary proper motion RA: 12
- Primary proper motion DEC: -12
- Secondary proper motion RA: 8
- Secondary proper motion DEC: -12
- Durchmusterung:
- Notes: