https://astro.t3k.pl/en/tags/leo/Recent content in Leo on AstroT3kHugo -- gohugo.ioenSun, 08 Mar 2026 21:00:00 +0100https://astro.t3k.pl/en/post/2026/03/m66_leotriplet/Sun, 08 Mar 2026 21:00:00 +0100https://astro.t3k.pl/en/post/2026/03/m66_leotriplet/<img src="https://astro.t3k.pl/" alt="Featured image of post Leo Triplet — M65, M66 and NGC 3628" /><p><img class="gallery-image" data-flex-basis="359px" data-flex-grow="149" data-title-escaped="Leo Triplet — M65, M66 and NGC 3628" height="1696" loading="lazy" sizes="(max-width: 767px) calc(100vw - 30px), (max-width: 1023px) 700px, (max-width: 1279px) 950px, 1232px" src="https://astro.t3k.pl/images/2026/m66_leotriplet/m66.png" title="Leo Triplet — M65, M66 and NGC 3628" width="2538"></p> <p>The Leo Triplet is a compact group of three bright spiral galaxies in the constellation Leo, lying roughly 35 million light‑years away. Their mutual gravity has sculpted each member in a different way: deep exposures reveal a sprawling, ultra‑faint tidal tail streaming from NGC 3628, while M66 shows lopsided spiral arms and star‑forming knots, and M65 remains the most quiescent and smooth of the trio.</p> <p>From mid‑northern latitudes the Triplet is a spring classic, culminating high in the south around March–April. It is an easy star‑hop a few degrees south of Chertan (Theta Leonis). In small telescopes all three fit in the same low‑power field as elongated smudges; larger apertures and dark skies begin to show the dark lane in NGC 3628 and mottling in M66. Long integrations under Bortle 5 skies help draw out the dim outer discs and the halo glow that binds the group together.</p> <p>M65 (NGC 3623) is an early‑type spiral seen at moderate inclination. It presents a bright, condensed core embedded in a smooth disc with only gentle arm structure. A subtle dust lane hugs one edge of the disc; overall the galaxy appears relatively undisturbed, with a yellowish bulge signalling an older stellar population and only modest current star formation.</p> <p>M66 (NGC 3627) is slightly larger and brighter than M65, with a weak bar and two asymmetric arms that have been tugged by interactions within the group. Its spiral pattern shows pronounced dust lanes and patchy, bluish H II regions. The skewed outer arm and off‑centre appearance are classic signs of tidal encounters that have stirred gas and triggered new stars.</p> <p>NGC 3628, the edge‑on “Hamburger Galaxy”, is bisected by a thick, dark dust band that swells above and below the mid‑plane. In very deep images a spectacular tidal tail extends far to one side — a stream of stars pulled out by past interactions. Even when the tail is beyond reach, the boxy bulge and flared dust lane make NGC 3628 the most dramatic silhouette in the field.</p> <h4 id="what-else-is-in-this-image">What else is in this image? </h4><p><img class="gallery-image" data-flex-basis="188px" data-flex-grow="78" data-title-escaped="What else is in this image? — Leo Triplet annotated" height="6693" loading="lazy" sizes="(max-width: 767px) calc(100vw - 30px), (max-width: 1023px) 700px, (max-width: 1279px) 950px, 1232px" src="https://astro.t3k.pl/images/2026/m66_leotriplet/annotated_m66.png" title="What else is in this image? — Leo Triplet annotated" width="5256"></p> <table> <thead> <tr> <th></th> <th></th> </tr> </thead> <tbody> <tr> <td>Telescope</td> <td>SkyWatcher 150/750P</td> </tr> <tr> <td>Mount</td> <td>ZWO AM3N</td> </tr> <tr> <td>Camera</td> <td>ZWO ASI2600MC Pro</td> </tr> <tr> <td>Filters</td> <td>none</td> </tr> <tr> <td>Exposure</td> <td>64 × 120s (2h 8min)</td> </tr> <tr> <td>Bortle</td> <td>5</td> </tr> <tr> <td>Moon</td> <td>Waning gibbous (77.2%)</td> </tr> <tr> <td>Processing</td> <td>SetiAstro Suite Pro, Prism Deep, Axiom V2, CosmicClarity</td> </tr> </tbody> </table>