A recent observation by the NASA/ESA Hubble Space Telescope has yielded a novel depiction of the lenticular galaxy designated NGC 7722.
This Hubble image shows NGC 7722, a lenticular galaxy some 187 million light-years away in the constellation of Pegasus. Image credit: NASA / ESA / Hubble / R.J. Foley, UC Santa Cruz / Dark Energy Survey / DOE / FNAL / DECam / CTIO / NOIRLab / NSF / AURA / Mehmet Yüksek.
NGC 7722 is situated approximately 187 million light-years from Earth, residing within the celestial sphere of Pegasus.
This lenticular galaxy, also identified by the designations IRAS 23361+1540, LEDA 71993, and UGC 12718, was initially brought to scientific attention by the German astronomer Heinrich Louis d’Arrest on August 12, 1864.
NGC 7722 constitutes a component of the NGC 7711 group, an aggregation comprising seven substantial galaxies.
“A lenticular (lens-shaped) galaxy represents a classification that occupies an intermediate position between the more commonly recognized spiral and elliptical galaxies,” stated the Hubble astronomers in a released communiqué.
“Furthermore, it is less prevalent than these counterparts, partly because galaxies exhibiting ambiguous morphologies can present challenges in accurately classifying them as definitively spiral, elliptical, or a transitional form.”
“A significant number of cataloged lenticular galaxies display characteristics inherent to both spiral and elliptical galaxy types.”
“In the instance of NGC 7722, it lacks the discernible spiral arms characteristic of spiral galaxies, while simultaneously possessing an expansive, luminous halo and a prominent central bulge, traits reminiscent of elliptical galaxies,” they elaborated.
“In contrast to elliptical galaxies, it exhibits a discernible disk, with concentric rings encircling its radiant nucleus.”
“However, its most striking attribute is undoubtedly the elongated bands of deep red dust intricately wound around its outer disk and halo.”
The recent image of NGC 7722, captured by the Hubble’s Wide Field Camera 3 (WFC3) instrument, renders the galaxy’s striking dust lanes in exceptionally clear detail.
“Dust bands of this nature are not an infrequent occurrence in lenticular galaxies, and they contrast sharply against the broad, uniform halo of light that conventionally envelops these celestial bodies,” remarked the astronomers.
“The distinctive dust lanes observed in NGC 7722 are theorized to be the consequence of a past galactic merger event, a phenomenon observed in other lenticular galaxies.”
“The precise mechanisms governing the formation of lenticular galaxies remain a subject of ongoing research, though mergers and other gravitational interactions are presumed to play a pivotal role, reshaping galactic structures and depleting their gas reserves while simultaneously introducing new dust material.”
