21209+2720
- Unique Name: 21209+2720COU 729
- RA: 21 20 55.53
- Dec: +27 19 38.6
- Discoverer: COU
- Discoverer Number: 729
- Components:
- First year: 1971
- Last year: 2007
- Observations: 8
- First position angle: 318
- Last position angle: 316
- First separation: 0.2
- Last separation: 0.2
- Mag first component: 10.2
- Mag second component: 10.2
- Spectral type: A3
- Primary proper motion RA: -8
- Primary proper motion DEC: -15
- Secondary proper motion RA:
- Secondary proper motion DEC:
- Durchmusterung: +26 4133
- Notes: