Object of the Week August 30, 2015 NGC 7742 (The Fried Egg Galaxy)

[Jimi Lowrey]

NGC 7742

Pegasus

RA
23 44 15

DEC
+10 46 00

MAG V 11.9

Type Seyfert II AGN SA

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I must say I am not a big fan of the name Fried Egg Galaxy that the Hubble team hung on this unusual galaxy in 1998. The enhanced image below is how it got the name.

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NGC 7742 is a most unusual type of galaxy. A non barred galaxy with a AGN and a nuclear ring. It was found by W Herschel in 1784 with his 18.7" reflector and lies at a distance of 70MLY. Most nuclear ring galaxies have a bar, but not NGC 7742. There is much debate as to how it got its star forming ring. One idea is it had a minor merger with a small gas rich dwarf galaxy and enhanced the core of the super massive black hole at it's center. This galaxy is in the same class as Hoags Object and no one has a clue as to how it formed.

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While I was doing research on this galaxy I found in the NED notes that the ring in NGC 7742 was rich in H beta and O III. This got me to thinking the many H II knots in the ring might be enhanced with the DGM galaxy contrast filter. Below I inverted the Hubble image to show the many H II regions in the ring.

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I am anxious to hear of your observations of this unusual galaxy and I will let you know of my results with the DGM GCF filter and as always

"GIVE IT A GO AND LET US KNOW"

[Ivan Maly]

Here is what I have on this galaxy and its neighbor, from three years ago with 16" at a remote site:

NGC 7742 and 7743 are a pair of spirals less than 1 degree apart near 77 Peg. Both are Herschel objects. They are modestly sized (40 and 55 kly) at 81 and 83 Mly. Both are easily visible at 45x. 225x shows that NGC 7743 is elongated EW (1.5x1) and is concentrated to a sharp nucleus. NGC 7742 remains round in comparison and lacks a nucleus, but it is also concentrated.

Great, now I want fried eggs... thanks, Jimi.

[Howard B]

I have one observation from 1999:

"This galaxy has a nice bright core with a stellar point in its middle. Vague edges blend quickly into the black of space. Bracketed by an attractive field of stars. 413x" 20 inch f5.

No sketch this time, but oddly I did have eggs for dinner about an hour ago...

[Atlas]

Jimi,

very interesting object indeed. I tried it last night. What I saw was a bright stellar core sitting in the center of a disk. Only at moments of good seeing, which were few, I could see that the disc is truely a ring.

Johannes