Messier 66 (NGC 3627): A Galaxy Member of the Leo Triplet

A small cluster of galaxies graces the spring sky in the constellation Leo. This grouping called the Leo Triplet, consists of spiral galaxies Messier 65, Messier 66, and NGC 3628. Though these three objects are dim and can be a struggle to see from suburban skies, backyard astronomers will appreciate that they are close together, so finding one aid in navigating to the others.

Messier 66 (M66) is best viewed during early springtime. In smaller telescopes, it will appear long and thin, mirroring the observation recorded by Charles Messier on March 1, 178O calling the object: “Very long and very faint.”

My Observations

Like most galaxies I view from the backyard, M66 is rather dim. Trying different eyepiece powers helps, and I landed on 14mm. It is a diagonal wisp of gray streak running just below a few brighter stars.

Key Stats

Constellation	Leo
Best Viewing	Spring
Visual Magnitude	+8.9
Absolute Magnitude	-21.4
Distance from Earth	37 million ly
Diameter	111,000 ly
Apparent Size	10.3 x 4.6 arcmin
Milky Way Location	N/A
My Viewing Grade	B-

Historical Observations

Entry dated March 1, 1780 by Charles Messier

Nebula discovered in Leo; its light is very faint & it is very close to the preceding M65: They both appear in the same field [of view] in the refractor. The comet of 1773 & 1774 has passed between these two nebulae on November 1 to 2, 1773. M. Messier didn’t see them at that time, no doubt, because of the light of the comet.’²

Sources and Notes

Photo of M66 by NASA/ESA and The Hubble Heritage Team (STScI/AURA). Photo is in the public domain because it was created by NASA and ESA.

¹https://en.wikipedia.org/wiki/Sombrero_Galaxy

²Historical observation from messier.seds.org.

Sketch by Wayne McGraw