Ophiuchus

When and where to look for Ophiuchus

Ophiuchus crosses the meridian — its highest point in the sky — at local midnight around June, which makes the months from May to July the easiest time to find it in the evening. It spans declinations -29.9° to +12.6°, so best from the southern hemisphere; it rises for observers between about 77°S and 60°N.

The quickest way to find it is to open the live AR sky map and point your phone at the sky — if Ophiuchus is above your horizon right now, its figure is drawn in the position it genuinely occupies above you.

Brightest stars in Ophiuchus

Magnitude runs backwards: lower numbers are brighter, and anything below about 6.5 is beyond the naked eye under a dark sky.

What Ophiuchus is made of

The catalogue lists 173 stars within Ophiuchus, of which 173 are magnitude 6.5 or brighter — the limit of what an unaided eye picks up under a genuinely dark sky. The rest need binoculars or a telescope.

Spectral make-up

Spectral class is a temperature ordering, running from O at around 30,000 K down to M below 3,500 K. A constellation is a direction, not a group, so this is simply what happens to lie along that line of sight.

The closest catalogued star in this direction is 70 Oph at 16.6 light years. The most distant is HD 171247 at roughly 1,822 light years — stars that appear side by side here are nothing of the sort.