A significantly red star is located near the border with Hadonoš, a supergiant whose brightness irregularly varies between 3.1 mag and 3.9 mag, often only between 3.3 mag and 3.7 mag. The period is 90 to 100 days. Suitable comparison stars are ι and κ Ophiuchi, which are located about 6.5 degrees to the southwest and have a brightness of 4.3 mag and 3.2 mag, respectively. Alpha Herculis is also a binary star, with its second component of fifth magnitude located 4.7" away, visible even in small telescopes with a 6 cm objective diameter. It has a greenish tint that nicely contrasts with the red giant.