NGC 3621 is a spiral galaxy located approximately 22 million light-years away in the constellation of Hydra. It possesses some notable characteristics that make it a fascinating candidate for study by both professional astronomers and amateurs. Firstly, it is one of the few spiral galaxies that does not have a prominent central bulge, being classified as a pure disc spiral galaxy. This means that its structure is dominated by a disc filled with young stars, dust, and star-forming regions.

The disc of NGC 3621 displays well-defined spiral arms that are highlighted by the presence of HII regions, which are clouds of ionized gas where new stars are forming. These regions are often illuminated by young and massive blue stars, and the reddish glow observed in many of them is due to the emission of ionized hydrogen.

Interestingly, despite NGC 3621 not having a classic central bulge, detailed observations have revealed the presence of a supermassive black hole at its core. This fact is intriguing, as the presence of supermassive black holes is often associated with galaxies that have substantial bulges.

Moreover, NGC 3621 is often studied in the context of the Tully-Fisher relation, an empirical relationship between the luminosity of a galaxy and the rotation speed of its disc. This relation is fundamental for understanding the total mass of galaxies and contributing to the estimates of extragalactic distances, a key piece in constructing the cosmic distance scale.

The captured image of NGC 3621 illustrates the beauty and complexity of this astronomical object. The details of its structure can provide important clues about the formation and evolution of bulgeless spiral galaxies and about the physical processes that occur in galactic discs.


WordWide Telescope:



The green filter ended up with twice the acquisitions because I forgot to change the filter in N.I.N.A. I only realized it the following day and since I already had them, I made use of it.