21228+4031
- Unique Name: 21228+4031HO 287
- RA: 21 23 01.74
- Dec: +40 35 39.3
- Discoverer: HO
- Discoverer Number: 287
- Components:
- First year: 1889
- Last year: 2002
- Observations: 9
- First position angle: 9
- Last position angle: 7
- First separation: 1.6
- Last separation: 2.6
- Mag first component: 11.06
- Mag second component: 11.16
- Spectral type:
- Primary proper motion RA: -9
- Primary proper motion DEC: -12
- Secondary proper motion RA: -6
- Secondary proper motion DEC: 17
- Durchmusterung: +39 4539
- Notes: