Discussion in the GHS Group about the corrected use of BlurXterminator, using a L-mask.  This image uses the technique. 

The 1h of exposure here represents 3h of collection in the San Francisco Bay area with Subframe Selector removing 2/3 of the images.  

From Wikipedia:

NGC 5982 is an elliptical galaxy located in the constellation Draco. It is located at a distance of circa 130 million [url=mw-redirect=https://en.wikipedia.org/wiki/Light_year]light years[/url] from Earth, which, given its apparent dimensions, means that NGC 5982 is about 100,000 light years across. It was discovered by William Herschel on May 25, 1788.=reference[3]NGC 5982 has a kinematically decoupled nucleus, with its major axis being nearly perpendicular to the rotation of the galaxy.=reference[4]


NGC 5982 features many [url=mw-redirect=https://en.wikipedia.org/wiki/Shell_galaxy]shells[/url] in its envelope, nearly 26. The shells form circular arcs, with the further being located at a radius of 150 arcseconds along the major axis of the galaxy,=reference[5] while the innermost one lies 8 arcseconds off the nucleus.=reference[6] The shells and the kinematically decoupled nucleus are the result of the merger of the elliptical galaxy with a small elliptical galaxy.=reference[5]The galaxy has globular clusters that belong in two populations, red and blue. The age of the globular clusters in NGC 5982 is over 5 billion years.=reference[7] The luminosity of NGC 5982 is dominated by light emitted by old stars.=reference[5] In the centre of NGC 5982 lies a supermassive black hole whose mass is estimated to be =nowrap8.3×108 M☉ (108.92 M☉) based on the M–sigma relation.=reference[8] The nucleus may display low level activity and has been categorised as a possible [url=mw-redirect=https://en.wikipedia.org/wiki/LINER]LINER[/url].=reference[9]=reference[5]=thumb tright=thumbinner=thumbcaptionNGC 5981 (right), NGC 5982 (centre), and NGC 5985 (left) form a close trio of galaxies.


NGC 5982 belongs to a galaxy group known as the NGC 5982 group. Other members of the group include the galaxies [url=new=https://en.wikipedia.org/w/index.php?title=NGC_5976&action=edit&redlink=1]NGC 5976[/url], [url=new=https://en.wikipedia.org/w/index.php?title=NGC_5981&action=edit&redlink=1]NGC 5981[/url], NGC 5985, [url=new=https://en.wikipedia.org/w/index.php?title=NGC_5987&action=edit&redlink=1]NGC 5987[/url], and [url=new=https://en.wikipedia.org/w/index.php?title=NGC_5989&action=edit&redlink=1]NGC 5989[/url].=reference[10] NGC 5981, a spiral galaxy seen edge-on, lies at a separation of 6.3 arcminutes from NGC 5982 and NGC 5985, a spiral galaxy seen face-on, lies at a separation of 7.7 arcminutes.=reference[11] The three galaxies are known as the Draco Trio or the Draco Group, although there is no evidence that they form a compact group.=reference[12]