Quote:
Originally Posted by Weltevreden SA
03/31/2013:
—I have a question about the many so-called ‘star lines’ in the HST 3603 and so many other astro photography images I see. (....)
(....) Counting very quickly, I see around 20 apparent lineations of 4 or more stars of perhaps 2 mag difference with respect to each other, marching in all directions across the 3603 image.(.....)
(......)Check out NGC 5460—an OC that at the eyepiece looks like a snake charmer did it. At one time I thought ‘star lines’ might by MHD artifacts—stars lining up with magnetic field lines.
=Dana |
The unusual structure of NGC 5460 looks physically real to me, rather than to be an artefact of the human imagination. Here is an image of it, from wikisky.org:
In the olden days, I used to visually observe a lot of OB associations, objects which are (by definition) gravitationally unbound; and OB associations often have an elongated or linear structure, similar to what is seen in NGC5460.
(( I have briefly covered OB associations in two threads within the Science Forum, entitled: "OB associations - a quick introduction" and "OB associations - another perspective" )
[[ A good case study of the way in which the human imagination can get in the way of a proper analysis of physical reality is the case of the large scale structure of the galaxy M31.....people kept looking for large-scale and high-contrast spiral structure in this galaxy; therefore their conceptual/imaginative prejudices meant that (for several decades) they didn't notice that the strongest structure within the Disk Component of M31 is actually a supergiant-sized ring! ]]
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I have (in visually observing) previously looked at the "nearby" elliptical galaxy PGC 50448 = ESO 221-026 ......
but in true "galaxyman" fashion I have always absolutely ignored the star cluster!! (as per the following anecdote about my "galaxies obsession")
True Anecdote from a star party:
Observer 1 (waving his arms in excitement, and literally screaming with joy) :: "There's a -1 magnitude comet blazing in the sky!!#$%%^!!!!!"
Madbadgalaxyman (as he peers at a very faint galaxy with his telescope) :: "Tell this to someone who cares! I won't let this unimportant announcement distract me, even for a second, from viewing this vanishingly faint galaxy!"