Astrodon LRGBSHO 2" Filters on Sergey's Astrophotography

NGC 6744: Spiral Galaxy in Pavo

Thu, 22 Oct 2026 10:40:00 +0000

NGC 6744 is an intermediate spiral galaxy (SAB(r)bc) in the constellation Pavo. ESO gives its distance as about 30 million light-years, while other estimates are lower, around 24 million. NASA gives its diameter as about 175,000 light-years, larger than the Milky Way. James Dunlop discovered it on 30 June 1826 from Parramatta, Australia.

ESO describes it as close to what our own galaxy would look like from outside, with spiral arms around a dense, elongated nucleus and a dusty disc. Its nucleus is a LINER with a low-luminosity active galactic nucleus. A distorted companion galaxy, NGC 6744A, resembles one of the Magellanic Clouds.

NGC 253: The Sculptor Galaxy

Thu, 22 Oct 2026 10:30:00 +0000

NGC 253, the Sculptor Galaxy, is also known as the Silver Coin Galaxy and is listed as Caldwell 65. It is the brightest galaxy of the Sculptor Group, about 11 million light-years away, with a diameter of about 120,000 light-years measured at the D27 isophote. Caroline Herschel discovered it in 1783 during a comet search. We see it at a high inclination, which makes its dust lanes stand out against the bright disc.

NGC 300: Spiral Galaxy in Sculptor

Thu, 22 Oct 2026 10:20:00 +0000

NGC 300 is a late-type spiral galaxy (SA(s)d) in the constellation Sculptor, about 6 million light-years away. It is also known as the Sculptor Pinwheel Galaxy and is listed as Caldwell 70. Its apparent size is about 22 by 15.5 arcminutes, and its spiral arms are loosely wound. James Dunlop discovered it in 1826.

Its distance has been measured from Cepheid variable stars. NGC 300 was traditionally counted as a member of the Sculptor Group, but recent distance measurements place it in the foreground, probably as a gravitationally bound pair with NGC 55.

NGC 1851: Globular Cluster in Columba

Thu, 22 Oct 2026 10:10:00 +0000

NGC 1851 is a globular cluster in the constellation Columba, about 39,500 light-years away. It is roughly 11 arcminutes across and has an apparent magnitude of about 7.3. James Dunlop discovered it in 1826. Its core is very compact, with a halo of stars extending well beyond it, and the long focal length resolves the outer regions into individual stars.

Its stars do not all share the same history: the subgiant branch splits into two populations, and the horizontal branch also shows two groups of stars. This has led to proposals that NGC 1851 is the product of a merger of two clusters, or the stripped nucleus of a dwarf galaxy absorbed by the Milky Way. The question is still debated.

NGC 346: Star-Forming Nebula in the Small Magellanic Cloud

Thu, 22 Oct 2026 10:00:00 +0000

NGC 346 is a young open cluster with an associated nebula in the constellation Tucana, about 200,000 light-years away. It lies near the centre of N66, the brightest H II region of the Small Magellanic Cloud, a satellite galaxy of the Milky Way. About thirty of its stars are hot, massive stars of spectral type O, and their radiation ionises the surrounding hydrogen. James Dunlop discovered it in 1826.

The Small Magellanic Cloud contains lower concentrations of elements heavier than hydrogen and helium than the Milky Way, so its star-forming regions resemble the conditions of galaxies billions of years ago. NGC 346 has also been observed by the James Webb Space Telescope, which found more dust there than expected.