Object Of The Week April 02, 2017 - NGC 3726

NGC 3726, UGC 6537

Galaxy (in a group of galaxies)
Morphological type: SBc (Simbad), SAB(r)c (NED)

Constellation: Ursa Major
RA: 11 33 21.174
DEC: +47 01 44.73

Mag: 10.7 (B), 10.2 (R), 10.91 (NED)

Size: 6.2' x 4.3'

NGC 3726 is a bright, barred spiral galaxy in Ursa Major. It was discovered by William Herschel on February 5, 1788. According to Steve Gottlieb's NGC notes, Herschel positioned the galaxy at the north edge of the real position. According to the same notes, both Lord Rosse and R. Mitchell detected spiral arms in this galaxy.

Attachment 2526

Image by George Hickey/Adam Block/NOAO/AURA/NSF.

There are many bright galaxies in the northern spring sky that show spiral structure, so why this one? Well, mostly because it took me by surprise when I first observed it. I was working my way through the H400 list and I usually don't look up beforehand what to expect as to not be biased. So I pointed my 20" telescope at it and, much to my surprise, saw a beautiful spiral galaxy. My notes from March 13, 2015, read

"At 320x this is a beautiful, spectacular galaxy! I see an oval nucleus inside an S-shaped object. There is a circle around the oval nucleus and the arms extend beyond that. Superb!"

I write "much to my surprise" because even with a 20" telescope I often find it hard to spot detail in bright galaxies. It very much depends not only on the galaxy itself but also the sky conditions what I can see. Apparently the combination of the galaxy and the sky that night made for a great observation. My notes don't say if I tried higher magnifications, so I will need to revisit it.

One other reason I chose this galaxy is that it is bright and I am curious to know what people with smaller telescopes make of it.

Finally, when I looked up this galaxy on Simbad, I found the description "galaxy in a group of galaxies" curious. It turns out that Crook et al conducted a statistical analysis of the 2MASS Extended Source Catalog and found statistical evidence for many groups of galaxies. The full article can be found here

2007ApJ...655..790C

Unfortunately it remains unclear to me what group NGC 3726 allegedly belongs to since part of Simbad is offline for maintenance. I'll update this text as soon as they're back online.


As always,

"Give it a go and let us know!
Good luck and great viewing!"

NED lists it as part of LGG 258 which contains

LGG 258 PGC36343 UGC 6667 113942.0+515300 S 1061
LGG 258 PGC37036 NGC 3917 114807.7+520614 S 1055
LGG 258 PGC37164 UGC 6840 114930.0+522307 S 1133
LGG 258 PGC37306 NGC 3953 115112.9+523620 S 1142
LGG 258 PGC37553 UGC 6923 115414.3+532623 I 1159
LGG 258 PGC37617 NGC 3992 115501.0+533913 S 1142
LGG 258 PGC37735 UGC 6983 115634.0+525908 S 1171
LGG 258 PGC37525 UGC 6917 115354.4+504223 S 989
LGG 258 PGC37760 NGC 4026 115651.1+511425 L 1013
LGG 258 PGC38302 NGC 4088 120303.1+504913 S 841
LGG 258 PGC37072 NGC 3922 114836.2+502559 S 1080
LGG 258 PGC35676 NGC 3726 113038.3+471813 S 907
LGG 258 PGC36136 NGC 3782 113640.2+464728 S 792
LGG 258 PGC36188 UGC 6628 113725.5+461309 S 902
LGG 258 PGC36699 NGC 3877 114329.4+474618 S 964
LGG 258 PGC36875 NGC 3893 114601.1+485920 S 1041
LGG 258 PGC36897 NGC 3896 114619.1+485710 S 938
LGG 258 PGC37136 NGC 3928 114910.1+485734 E 1049
LGG 258 PGC37290 NGC 3949 115105.2+480816 S 863
LGG 258 PGC37542 NGC 3985 115406.7+483648 S 1023
LGG 258 PGC37697 NGC 4010 115603.2+473220 S 971
LGG 258 PGC37722 UGCA 259 115618.0+460000 I 1210
LGG 258 PGC36686 NGC 3870 114316.9+502843 L 830
LGG 258 PGC38370 NGC 4100 120336.4+495136 S 1153
LGG 258 PGC38795 NGC 4157 120834.6+504551 S 859
LGG 258 PGC39241 NGC 4217 121321.7+472212 S 1090
LGG 258 PGC39285 NGC 4220 121342.9+480945 L 1051
LGG 258 PGC36528 UGC 6713 114145.6+490647 S 967+
LGG 258 PGC36825 UGC 6773 114522.1+500510 I 999+
LGG 258 PGC37045 MK 1460 114812.8+483146 856+
LGG 258 PGC37073 NGC 3931 114836.2+521644 L 931+
LGG 258 PGC37217 NGC 3924 115002.4+501858 S 1071+
LGG 258 PGC37682 UGC 6956 115551.0+511140 S 999+
LGG 258 PGC37700 UGC 6969 115606.0+534200 I 1208+
LGG 258 PGC38781 UGC 7176 120825.0+503353 I 970+
LGG 258 PGC38951 UGC 7218 121024.0+523300 I 864+
LGG 258 PGC38645 NGC 4142 120700.6+532258 S 1253+
LGG 258 PGC36008 NGC 3769A 113508.0+480939 S 823+
LGG 258 PGC37550 UGC 6922 115412.0+510700 S 958+
LGG 258 PGC38283 NGC 4085 120250.5+503756 S 833+
LGG 258 PGC38392 NGC 4102 120351.6+525923 S 931+

and also the UMa cluster https://en.wikipedia.org/wiki/Ursa_Major_Cluster. You can always use NED if SIMBAD is down and it is probably better for extragalactic objecst anyway.

Owen

Thanks very much, Owen!

Very nice. Observing last year (12", 230x, SQM 21.64), I recorded:

NGC 3726. Small sharp nucleus. One arm sharply curves E from S end of core. Another runs from N end along E [sic, should be W] edge. A more diffuse streak parallels it to W. This one is outside line between stars.

As you already mentioned Wouter, NGC 3726 belongs to the very first object in which spirals were detected. I had a chance to catch theses details when I tried to see and sketch all mentioned spirals from Parsons between 1850-1861. With 14.5" the main spirals and dark structures were visible. To my own sketch I add two historical sketches.

sketch 1856-1858
Attachment 2527

sketch 1861
Attachment 2528

sketch, 14.5", 202x, NELM 6m5+, Seeing II
Attachment 2529