To the east and a little north of 70 Oph is a rectangular inclusion of the Ophiuchus border into the area of Serpens. Within this constellation cul-de-sac are two targets of the Struve family - one easy and one not so much, but both successfully resolved with my 90mm refractor.
STTA 170 - 18h 30.7m +04d 31' 6.97, 8.75 100" 5d PA (2015) A2 White, purple. 36X
STF 2322 - 18h 30.1m +04d 04' 6.67, 11.28 19.8" 172d PA (2009) B2V
12.79 67.2" 295d PA (2015)
White, no color, no color. C star only seen with averted vision. Visually, both the B and C components seem one magnitude brighter than their measured values.
Also in the immediate neighborhood are several variables, most notably of which is the carbon star TY Oph. (Hi Aubrey ) Using an AAVSO chart, I estimated its magnitude at 10.1 and judged its color as decidedly pink. 36X Might take a bit more aperture to enhance the color to the typical red of carbon stars.
All in all, a diverting, quiet little "block on the border" before the sky turns snakey.
Edited by VanJan, 05 August 2020 - 11:28 PM.