tag:blogger.com,1999:blog-18462047.post7032047639246680114..comments2023-12-31T20:16:09.115-05:00Comments on lumpy darkness: imaged St. Katherine's Wheel (Halifax)blahttp://www.blogger.com/profile/14004187330936108058noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-18462047.post-79920583184885912562023-05-07T16:02:47.207-04:002023-05-07T16:02:47.207-04:00The central core of spiral galaxies seem to come i...The central core of spiral galaxies seem to come in a couple of flavours. The two main ones I know are "regular" for lack of a better term and "barred."<br /><br />A regular core is just a spherical ball shape. I believe the early impression of our galaxy was that it had a spherical galactic bulge and you'll see many renderings drawing or illustrated that way. Perhaps flattened but still a ball shape. These types of galaxies seem to have multiple arms, spinning out. A bit like those rotating fireworks wheels. NGC 5457 is a very good example.<br /><br />But another core type is barred. Here are rod-like shape lies in the central region of the galaxy, lies flat or in-line with the disc. From the two ends of the rod or bar, two main arms of the galactic emerge and propagate. Often these galaxies seem to have two prominent arms only, like the two-bladed screw or propeller on a boat. NGC 1300 exemplifies the structure.<br /><br />Hope that helps.blahttps://www.blogger.com/profile/14004187330936108058noreply@blogger.comtag:blogger.com,1999:blog-18462047.post-57712353092951573162023-05-07T15:34:32.557-04:002023-05-07T15:34:32.557-04:00What is a “ barred core”? I don’t know that term. ...What is a “ barred core”? I don’t know that term. Anonymoushttps://www.blogger.com/profile/14658986611672634680noreply@blogger.com