Spot the Difference: Arcturus and Antares

(Image Credit: Arcturus (left) and Antares (right) taken by yours truly on 19-May-2026)

Despite the partly cloudy evening skies on the 19th of May, it was at least favorable for me to view two identical bright and reddish stars. Arcturus is already discussed in my previous article ***(here). ***This time, let’s have a comparison between the two stars.

(Image Credit: Arcturus (30mm) and (12.5mm) taken by yours truly on 19-May-2026)

A Quick Recap and Update of Arcturus

We already know that this red giant star is already 7 to 10 billion years old with the same mass as the sun. It’s around 36.7 light-years away from us with an apparent magnitude of -0.05. We can spot further on the eastern side of the Ursa Major constellation going to the brightest dot of the Boötis constellation. Arcturus is one of the Spring Triangle members like Regulus and Spica.

From my telescope that night, Arcturus appeared to be in a yellowish-orange hue. It continued to illuminate the sky within an hour as it ascended around 90 degrees above my position. It was too difficult to look-up further until it reached westbound. Even the clouds were appearing and travelling on the skies, it remained radiant and visible with 12.5 mm and 30 mm eyepieces.

(Image Credit: Antares (30mm) and (12.5mm) taken by yours truly on 19-May-2026)

The Rival of Ares appears on the Skies

Alpha Scorpii aka ‘Antares’ is the brightest star in the Scorpius constellation with an apparent magnitude of 0.6 to 1.6. It is 550 light-years away from our solar system. This red supergiant star is very massive since its mass is around 15 to 16 times that of our sun. It could be seen in the naked eye since it is one of the brightest and largest stars in our galaxy. It’s around 11 to 15 million years old.

Its name was derived from ancient Greek, meaning ‘rival of Ares’ because of its reddish hue and the relation to the Greek god of war in mythology.

Antares appeared to be a single star, but it is actually a binary star consisting of Antares A and B. Antares A is an extremely massive and bright red supergiant as its companion is a faint blue and hot main sequence star.

It is believed that it will explode as a supernova in 1 to 1.4 million years which it will be very visible during the day and brighter than our moon.

From my observation, I waited and spent extra thirty minutes on the telescope viewing. It had risen from the neighbor's tall eucalyptus trees on the southeastern side of my position. It was worth the wait which I took photos of the star’s absolute reddish-orange hue and brightness.

CONCLUSION

Antares is brighter, farther, and larger than Arcturus and our Sun as described in this article. Arcturus comes earlier around 20:00 to 22:00 than the Heart of the Scorpion in the evening skies. We can spend two hours and a half in viewing them.

I will leave another haiku for these two non-identical red stellar objects:

The two bright red stars, One is bigger than its friend, They rule the night sky.