HD 126009
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 22m 14.00070s |
| Declination | +29° 22′ 11.7179″ |
| Apparent magnitude (V) | 6.6 |
| Characteristics | |
| Spectral type | M3III |
| U−B color index | +1.46 |
| B−V color index | +1.60 |
| Variable type | Irregular |
| Astrometry | |
| Radial velocity (Rv) | −19.66±0.54 km/s |
| Proper motion (μ) | RA: −39.980 mas/yr Dec.: −26.201 mas/yr |
| Parallax (π) | 4.5229±0.0973 mas |
| Distance | 720 ± 20 ly (221 ± 5 pc) |
| Absolute magnitude (MV) | −0.268 |
| Details | |
| Mass | 1.8 M☉ |
| Radius | 71 R☉ |
| Luminosity | 943 L☉ |
| Temperature | 3,227 K |
| Age | 1.6 Gyr |
| Other designations | |
| CI Boötes, BD+30°2513, HD126009, HIP 70236, SAO 83312. | |
| Database references | |
| SIMBAD | data |
HD 126009 or CI Boötis is a variable star in the northern constellation of Boötes. With an apparent magnitude of 6.6, it would be extremely difficult to see with the naked eye even under the very best observing conditions, but can easily be seen with binoculars.
The German astronomer Wolfgang Strohmeier announced that HD 126009 is a variable star in 1960. It was given its variable star designation, CI Boötis, in 1978.