21504+3927
- Unique Name: 21504+3927HO 170
- RA: 21 50 26.80
- Dec: +39 26 31.8
- Discoverer: HO
- Discoverer Number: 170
- Components:
- First year: 1886
- Last year: 2007
- Observations: 40
- First position angle: 162
- Last position angle: 251
- First separation: 0.3
- Last separation: 0.3
- Mag first component: 7.92
- Mag second component: 10.05
- Spectral type: A3
- Primary proper motion RA: 9
- Primary proper motion DEC: -12
- Secondary proper motion RA: 9
- Secondary proper motion DEC: -12
- Durchmusterung: +38 4618
- Notes: