Messier 65 & Messier 66 (Leo)

Messier 66 (left) and Messier 65 (right) are two large spiral galaxies in the constellation Leo and, together with NGC 3628, form the well‑known Leo Triplet. This galaxy trio provides an impressive example of gravitational interactions between spiral galaxies, which can significantly influence their structure and star formation. Both galaxies are located about 35 million light‑years from Earth.

Messier 65 exhibits a comparatively regular spiral structure and shows a more moderate rate of star formation. Messier 66, in contrast, displays strongly asymmetric spiral arms and distorted dust features, indicating past or ongoing interactions with its neighboring galaxies. Star formation is particularly active in its central regions, making Messier 66 a more dynamic system than Messier 65. Numerical models and observations suggest that mutual tidal forces within the Leo Triplet are responsible for these differences. Such interactions can drive gas toward the inner regions of the galaxies, triggering star formation while simultaneously distorting their outer structures.

Messier 65 and Messier 66 were discovered in 1780 by Charles Messier and, thanks to their brightness and distinctive forms, are among the most popular galaxy targets for visual observation and astrophotography (source: Wikipedia).

Technical Details:
Exposure time: 1h 9min (23x3min)
Gain: 100
Date: April 16/17, 2026
Processing: Astro Pixel Processor (APP) and Photoshop
Calibration: Darks, flats, and bias

Equipment:
Cooled ASI 2600MC Pro camera, TeleVue Universal Paracorr coma corrector, 16" f/4.5 "Ninja" Dobsonian telescope on a dual-axis Tom Osypowski equatorial platform, ZWO OAG-L off-axis system, ASI 174MM Mini guide camera, ASIAIR Plus

Field of view comparison: image of the moon with the same setup.