66 Ceti: A Double Star of Buttery Yellow and Lavender

66 Ceti shines from the sea monster Cetus, swimming through the night skies of autumn to early winter. Backyard astronomers turning their scopes to 66 Ceti will find a close attractive pair of stars, one with a yellow hue and the other lavender in color.

According to Bob Argyle, the stars’ “position angle of 235 degrees and separation of 16″.8 has remained unchanged since 1783 when the pair was noted by William Herschel.” Furthermore, the primary yellow star has a binary star orbiting it. At a separation of .02, backyard astronomers are unable to see this pair.¹

My Observations

What an attractive double star with its buttery yellow primary and lavender secondary. A nearby red star shines stately with a neighboring darker and dimmer blue star. On nights like this, when the temperature is near freezing, I take in the radiance of stars like 66 Ceti with its ember glow.

And from my backyard, I look away from 66 Ceti and straight up. There past the light-polluted dark gray glow, somewhere among the stars peeking through, Artemis I is now halfway to the moon.

Key Stats

Constellation	Cetus
Best Viewing	Autumn
Visual Magnitude	+5.6, +7.7
Separation	16.9″ | 671 AU
Spectral Class	A=F8V, B=G1V
Absolute Visual Magnitude	+2.66
Distance from Earth	129 ly
Milky Way Location	Orion Spur
My Viewing Grade	A-

Sources and Notes

Banner illustration was created by the European Southern Observatory (ESO) and is under the Creative Commons Attribution 4.0 International License. Per ESO agreement: Here is the original image on the ESO website.

¹ Argyle, Bob. “Double Star of the Month in Cetus.” Webb Deep-Sky Society: Double Star of the Month in Cetus, https://www.webbdeepsky.com/double-stars/constellation?constellation=Cetus.

Sketch by Wayne McGraw

AKA: 66 Cet, SAO 129752, HD 13612, STF 231