Double star in Bootes
With an angular separation of 13.4", this fairly bright pair is easy to split with just about any telescope. Their orbital period is estimated to be over 6000 years.
Asellus Tertius means "third donkey colt", and with the naked eye it forms a small triangle with two other dim stars (Asellus Primus and Asellus Secundus, the other two donkey colts).
| Magnitudes | 4.5, 6.6 |
| Separation | 13.4" |
| Distance (light yrs) | 155 |
| Right Ascension | 14:13.7 |
| Declination | +51 45 |
| Field of View | 16' x 12' |
Image details: A series of 1-second exposures through clear, red, green, and blue filters, taken with an SBIG STF-8300M imager through a Meade 14” LX850 telescope at f/8.
July 2019