Psi5 Aurigae (56 Aur): A Yellow and Deep Dark Blue Pair

Psi5 Aurigae is an attractive multiple-color double star in the Auriga constellation, best viewed on winter nights.

The stars of Psi5, also known as 56 Aur, make a bright, colorful pair. The primary is a yellow main-sequence star (spectral type G0V) that graces the dark night with its golden hue. The star lies 55 light-years away from us. Meanwhile, the secondary companion is 29.4 arcseconds away and has a deep blue color. Due to the brightness and fairly wide separation of its stars, Psi5 makes a great target for backyard astronomers with a telescope.

Historically speaking, astronomer William Herschel first recorded this pair on November 6, 1782.

My Observations

Even though the seeing conditions are not excellent, I wanted to get some time under the stars since it has been many weeks since I’ve seen a clear sky. Unfortunately, bands of high clouds wash past Auriga, like they did a few nights ago, but my telescope is able to resolve some nice doubles on the region.

This is an attractive double star! The primary is yellow buttery golden, while the secondary is a deep blue. Other colorful pairs of gold and blue exist, even ones I’ve located during this session such as STF 698 and Phi Tauri, but I’d be amiss without mentioning how alluring the secondary blue star is. This is a beautiful deep dark blue.

Key Stats

Constellation	Auriga
Best Viewing	Winter
Visual Magnitude	+5.3 | +8.6
Separation	29.4″
Position Angle	42°
Spectral Class	A=G0V
Absolute Visual Magnitude	+4.13
Distance from Earth	54.5 ly
Milky Way Location	Orion Spur
My Viewing Grade	B+
Designations	56 Aur, HD 58682, SHJ 75, SAO 41330

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.

Sketch by Wayne McGraw