Note About The Object East Of The Galaxy
: This galaxy was brought to my attention because in the blue DSS image of the region there is what appears to be a bar-shaped object to the east of the galaxy, and in high-contrast images (such as the first one shown below), a sort of cloudlike area to the south of the bar. However, that feature does not show up on the red plate of the region (which is why the colored version is so blue), and as the PanSTARRS image shows, does not show up in any other image of the region, as well. So it appears
that the bar and cloud are some weird sort of plate defect (though as stated below, the PGC treated it as a separate galaxy). However, as noted in the NED, the object is real
; it just isn't present in any image of the region save the blue DSS plate because it is a comet (Comet Lovas 1974c = C/1974 F1) that was in that part of the sky whn the blue plate was taken, but not when any other image of the area was taken.
PGC Designation Note
: In the original PGC it was presumed that the 'bar' to the east of PGC 72568 was a "companion" galaxy, so it actually has a separate designation of its own, PGC 72569
, and any search of the LEDA database for either PGC designation brings up both of them, as though they are a single object. However, as pointed out above, that object was actually a comet that just happened to be passing through the region.
: Based on a recessional velocity relative to the Cosmic Microwave Background radiation of 3975 km/sec (and H0
= 70 km/sec/Mpc), PGC 72568 is about 185 million light years away. Given that and its apparent size of about 0.55 by 0.35 arcmin (from the images below), the galaxy is about 30 thousand light years across.
Based on recessional velocity of 7995 km/sec, about 360 million light years away. Given that and apparent size of 0.5 by 0.5 arcmins, about 50 thousand light years in diameter.
Note About Classification
: The Spitzer Survey of Stellar Structure in Galaxies
classification is Im: sp. The "sp" at the end stands for "spindle", and means that the galaxy is nearly "edge-on". It also means that the classification is not as accurate as it would be if we could see the galaxy "face-on". The colon after the "m" indicates that because it is hard to determine the classification, the "m" is uncertain. I have looked at the Spitzer images and they do not show the elongated disk to the northwest and southeast of the main galaxy that is visible in the image below (such extensions are harder to see in infrared images than in visible-light images). Given that visible-light extension, why LEDA and NED list this as a barred irregular galaxy is beyond my knowledge; the "type" shown in the description line is my educated guess based on the other classifications and the image below.
3.3 x 0.35 arcmin from image below