Object name: ABELL0194

Designation(s): ABELL0194, NGC0530, NGC0535, NGC538, NGC0541, NGC0543, ARP308, NGC0547, NGC0557, MINKOWSKIS_OBJECT, IC1696,

I took this area of the sky several years ago but wasn\'t happy with the color so gave it another try though the clouds did another number on it the result is a bit better. Abell 194 is a galaxy cluster a bit under a quarter of a billion light-years distant seen in the constellation of Cetus so runs rather low in my sky which doesn\'t help. It is far larger than my field of view being 3.75 degrees across. I aimed pretty much for the center which put its two Arp Atlas entries a bit off center to the upper left. Some of the text below is from my original attempt on this area.

Arp 133 falls under Arp\'s very odd category of galaxies with nearby fragments. It consists of two galaxies; NGC 541, the large cD/S0 galaxy and the \"fragment\". They lie to the southwest of a pair of elliptical galaxies that are Arp 308. The \"fragment\" is the very blue dwarf galaxy to its northeast (upper left). This is not a fragment at all but a dwarf galaxy undergoing extreme starburst star formation. It is known as Minkowski\'s Object. NGC 541 is a radio galaxy with jets. One is directed directly at Minkowski\'s Object and is credited with triggering the starburst activity. Minkowski\'s Object has a different redshift but this is more an indication of relative velocity than a real distance difference. Arp 133 with its blue companion galaxy is almost identical in appearance to the much nearer Arp 134 (M49 and its blue \"fragment\" UGC 07636.) http://www.spacebanter.com/attachment.php?attachmentid=2440&stc=1 Both give me the impression that the \"fragment\" is a bug splat on the leading edge of a \"solid\" galaxy that ran into it.

Arp had no knowledge of this at the time of his image. His image carries a note that it was taken with a \"Polaroid\" filter. I assume he means polarizing filter. How it was aligned it doesn\'t say. Arp\'s comment on the image reads: \"Central member of galaxy group associated with 3C40.\" 3C40 is a strong radio source but not the radio source involved with the starburst activity in Minkowski\'s Object. But it does bring us to Arp 308.

Arp 308 is a pair of galaxies; NGC 545 and NGC 547 that are associated with the radio source 3C40. That is NGC 547 is considered to be the source of 3C40 along with the small galaxy CGG 385-129 to the west. Arp put the NGC pair in his category of simply double galaxies. His simple remark says: \"Close ellipticals.\" which isn\'t very informative. NGC 545 to the north is listed as an SA0 galaxy while NGC 547 is E1 and a bright cluster galaxy. Redshift puts it at 6 million light-years further from us than NGC 545. However, NED gives a D-Sigma distance determination that is the same for both. Likely the difference in radial velocity is due to relative motion rather than distance. The exact same D-Sigma distance is found for NGC 541 (Arp 133) as well. Several sources say the pair are not interacting. It does appear to me that NGC 547 lies in front of NGC 545 based on the dark band between their cores which could be caused by dust in NGC 547 blocking the light of NGC 545 behind it.

NGC 519, 538, 557 was discovered by Lewis Swift on November 20, 1886
NGC 535, 543 was discovered by Heinrich d\'Arrest on October 31, 1864
NGC 541 (Arp 133) was discovered by Heinrich d\'Arrest on October 30, 1864
NGC 545, 547 (Arp 308) was discovered by William Herschel on October 1, 1785

Neither of Herschel\'s discoveries are in either H400 observing program.

There\'s one asteroid in the image. Its information is noted in the annotated image.

The annotated image includes the classification of each galaxy by NED. That of the NGC project for NGC galaxies is listed after the NED classification if different. When the same there is no second entry. Note only NGC galaxies are classified by the NGC Project.

Arp\'s image of Arp 133 with an asteroid trail:

Arp\'s image of Arp 308

My image from November 2011

14\" LX200R @ f/10, L=4x10\' RGB=2x10\' STL-11000XM, Paramount ME