Barnard's Galaxy (aka NGC 6822) is a barred irregular dwarf galaxy about 1.6 million light-years away (in Sagittarius near its border with Capricornus) that is a mere 7,000 light-years across. It is the closest non-satellite galaxy to the Milky Way, and is similar in structure and content to the Magellanic Clouds [†].

Many notable features of Barnard's Galaxy are displayed in this image, not the least of which are its bar and some of its many H II regions. The largest emission region is a giant expanding bubble some 400 light-years in diameter (beyond the upper-right periphery of the galaxy's main body), which is known, at the risk of a mistaken identity (!), as the "Ring Nebula"; next to that is a smaller HII region that to me has a distinctive heart shape, but that is known (again at the risk of some confusion!) as the "Bubble Nebula". Many blue star-forming regions stand out, while several OB associations can be identified easily using a finder chart in this detailed study of the galaxy; a curious extension of the galaxy to the lower left also contains many blue stars. And found throughout the galaxy's main body are fine tightly-packed red stars, which are individually-resolved red giants [#], along with many more stars evidently just below the image resolution that lend on overall reddish granular texture to the galaxy.

NGC 6822 was the first of three galaxies that Edwin Hubble analyzed in 1925 to make his historic determination of the extragalactic distance scale, using the period-luminosity relation for Cepheid variables that had been discovered by Henrietta Leavitt only a decade before, though she did not live to see this monumental accomplishment (the other two galaxies in Hubble's study were Andromeda, most famously, and Triangulum). A stunning JWST image of part of the galaxy was released in the summer, accompanied by a paper on a "proto" super star cluster embedded in one of the galaxy's H II regions, which are among the brightest such regions in the local universe.

The image spans about 26'x29' at a plate scale of 0.62”/pixel, and combines just under 33 hours of exposures in my CDK24, with about 19 hours in LRGB, and just under 14 hours in Ha (3nm-narrowband). I actually devoted about 56 hours of telescope time to get this image, but applied a fairly aggressive set of cuts in order to select subs of higher quality, especially cuts to the FWHM of star profiles in the luminance and Ha channels (the altitude of Barnard's Galaxy at culmination is less than 40 degrees at the location of the SRO). I acquired the data over the course of twenty-two nights from early July to early September.

[†] It seems that NGC 6822 is often compared specifically with the Small Magellanic Cloud (SMC), but to my eyes it seems much more like the Large MC, both of which have a very pronounced bar.

[#] Red giants crowd the central regions of almost all galaxies. To support the claim that red giants are individually resolved in this image, I made a very rough estimate of the limiting magnitude of well-defined red stars in the central region, finding it to be fainter than about 23, which is consistent with the apparent brightness of the dimmest red giants at the distance of NGC 6822 (to make the estimate, I used known magnitudes of red stars in this field of view, taken from the APASS database, which can be conveniently read-off from star charts generated by the AAVSO SeqPlot utility). By way of comparison, an image that I took of the south-west corner of the Andromeda galaxy resolved about 100,000 red giant stars, as I discussed in some detail in that post.