Object Of The Week April 16,2017---NGC 4197 "The Pitchfork Galaxy"

[Jimi Lowrey]

NGC 4197

Virgo

RA
12 14 38
DEC
+05 48 21

MAG 12.8 V

Type SB or Sd

"Pitchfork galaxy"

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Hi All, I am filling in for Dragan this week.

I am a big fan of edge on galaxies and NGC 4197 is a very unusual one. I just recently found out about NGC 4197 thanks to Sue French. I have never seen an edge on with a fork or split on one end before. When I first looked at a image of NGC 4197 I was curious as to what caused the split on the north end.

2537

I have done a considerable amount of research trying to find out the cause of the fork. I have looked through the 117 references in NED and have not been able to find the cause of the fork. It looks like there has been some kind of interaction or tidal distortion but I check the redshift of nearby galaxies and could not find any to be close to or near the redshift of NGC 4197. I hope there will be more research done on this peculiar edge on in the near future. For now the Morphology of NGC 4197 is a mystery.

2538

I have not observed NGC 4197 yet but it is high on my to do list. I will post my observations soon as I get a clear sky. I hope I will be able to see the fork and I look forward to hearing your observations of the Pitch Fork galaxy.


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

[obrazell]

Interestingly it is also catalogued as VV 520 in the catalogue of interacting galaxies. It is possible from the images that the fork is just a projection effect.

Owen

[Jim Chandler]

My log note from 2010 describes 4197 as "slightly distorted at one end". The warped end was seen but not the two tidal tails.

[Jimi Lowrey]

Owen I checked into the VV catalog designation with Steve Gottlieb and he wrote," VV included it in one of his stranger categories — “Prechains and Chains of different ages”. Perhaps he thought it was splitting into two or more galaxies as he made the comment" "The lower end begins to disrupt”

[Uwe Glahn]

I came across the galaxy because of its note "Two-layers, Bar, Splitted N-edge" in the RFGC.

For me it looks more like a ejection of the NE folk end and a resulting dark structure between the NW folk.

I found two entries in my log:
16", 255x, NELM 6m5+
faint, difficult to detect in searching eyepiece; with higher power not extremely flat; axis ratio 1:4; abrupt NE end; small hook not visible

27", 419x, fst 6m5+
[I]even with bigger aperture low surface brightness; central region mottled, detailed observation shows two separated parts; NE hook visible as a small and faint structure, before the small hook bends to the E another reversed arch is visible to the W; at the SW end a fainter separated part is visible; a small separated part at the NE end behind the arc suspected; the folk itself is not visible; companion 2' NW with averted vision

2539

[Norman]

my notes are reading "already easy in searching eyepiece (26 mm); nicely thin appearance." Very easy galaxy of the RFGC.
Working power at least around 120x. Cannot say if i also tried 200x. So no further detail.
NELM around 6m5, no mountain, just good rural site.

CS
Norman