21099+4257
- Unique Name: 21099+4257LDS2492
- RA: 21 09 49.77
- Dec: +42 57 20.6
- Discoverer: LDS
- Discoverer Number: 2492
- Components:
- First year: 1954
- Last year: 2002
- Observations: 4
- First position angle: 135
- Last position angle: 135
- First separation: 21.0
- Last separation: 21.5
- Mag first component: 15.37
- Mag second component: 15.64
- Spectral type:
- Primary proper motion RA: 202
- Primary proper motion DEC: -19
- Secondary proper motion RA: 202
- Secondary proper motion DEC: -19
- Durchmusterung:
- Notes: