The Spider (and not its web)

This gauzy-looking celestial body is UGC 5829, an irregular galaxy that lies about 30 million light-years away. Despite there not being many observations of this relatively faint galaxy, it has the distinction of having a descriptive soubriquet: the Spider Galaxy. Perhaps the distorted galactic arms with their glowing, star-forming tips bring to mind the clawed legs of an arachnid. Somewhat confusingly, there is another, very similarly nicknamed but otherwise entirely distinct, galaxy known as the Spiderweb Galaxy. This galaxy has also been more extensively imaged (notably by Hubble), despite the fact that it lies about 300 times further from Earth than the Spider Galaxy does. 

Fortunately, correct galaxy identification does not depend on casual given names. Rather, known galaxies are recorded in at least one catalogue — and often in several — such as the Uppsala General Catalogue of Galaxies, which gives the Spider Galaxy its more formal title of UGC 5829. This same galaxy also has several different designations in various other catalogues: it is, for example, LEDA 31923 in the Lyon-Meudon Extragalactic Database; MCG+06-24-006 in the Morphological Catalogue of Galaxies; and SDSS J104242.78+342657.3 in the Sloan Digital Sky Survey Catalogue. The Spiderweb Galaxy isn’t recorded in all of the same catalogues — each is necessarily limited in scope — but it is included in the LEDA catalogue as LEDA 2826829. It is evidently simpler to not conflate the dull but distinct names LEDA 31923 and LEDA 2826829, than the fun but easily confused Spider and Spiderweb!

[Image Description: An irregular galaxy, consisting of a large central body of dull-coloured stars, with distorted arms around it. The arms are spotted with brightly glowing pink areas where stars are forming, and bluish gas that is brighter than the galactic core. Two large arms flank the left and right of the body, and smaller streams of stars emerge from the top. Other, distant, galaxies can be seen on the edges of the image.]

Links

• Pan of UGC 5829