NGC 1097

Historical observations

William Herschel (c.1784)

Synonyms:H V-048

Discovered in 1790 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "vB, E 76 degrees np-sf, 8' long. A very bright nucleus, confined to a small part, or about 1' diameter."

John Herschel

John Herschel recorded it as "B, L, vmE, pspmbM, 3' long; pos = 151.1 degrees." The second observation reads: "B, L, vmE, psvmbM to a pL, R nucleus; 4' long, 40 arcseconds broad."

Published comments

Hardcastle, J.A. (1914)

Hardcastle, J.A. (1914) Nebulae seen on the Franklin-Adams plates. MNRAS, 74(8), 699-707. [commentary in Shapley, H. & Ames, A. (1932) A survey of the external galaxies brighter than the thirteenth magnitude.]

The following have not, I believe, been described before: -

NGC 1097 ! ! eBN, arms ext. to 6'x8', central spindle 6' in 144°

Helwan Obs. Bulletin No 15 (1915)

"!! pF, 8'x8', spiral, central part pB, 4'x2' E 140deg, vB and extremely complex nucleus."

Helwan Obs. Bulletin No 22 (1921)

!! pF, 9'x5.5', E 135deg; spiral with very complicated N which consists of a F alm.stell.centre surr. by 4 or possibly 5 B patches of nebulosity. The whole N has rather the appearance of a planetary nebula 0.5' diameter. The rest of the nebula is also interesting, being of the psi-type with much complicated structure in the cross-arm, which is in PA 140deg. There are many alm.stell. condensations in the 'circle' of the psi in which there is a gap in PA 280deg approx. See HOB 15. See also plates I and III. The nucleus is shown separately.

Doig, P. (1925)

Doig, P. (1925) Notes on the nebulae and clusters in Webb's 'Celestial Objects for Common Telescopes' (Sixth edition, Vol.ii). Part II. M.N.R.A.S., 35(8), 280.

Shapley, H. & Paraskevopoulos, J.S. (1940)

Galactic and Extragalactic Studies, III. Photographs of thirty southern nebulae and clusters. Proc. N.A.S., 26, 31-36.

Sulentic & Tifft (1973)

(Sulentic and Tifft 1973) notes that this is a 10.5 mag galaxy. Their coded description reads SB,B,LGE,DKLNS NRNUC OKNWD ARMS.

Green, M. R. & Dixon, K. L. (1978)

"Photoelectric photometry of bright southern galaxies", Vol 98, August, p 167-169. They find the V magnitude through a 28'' aperture = 11.6, and through a 80'' aperture = 11.0.

Sandage, A. (1961) The Hubble Atlas of Galaxies

This galaxy appears on page 46 of "The Hubble Atlas of Galaxies" by Allan Sandage (1961, Washington, DC).

Arp (1966)

Listed as No. 77 in Arp's "Atlas of Peculiar Galaxies" (Astrophysical Journal Supplement, vol. 14, 1966.) He remarks "material of arm seems to flow 'around' companion. Similar to Arp 26. [NGC 5457]."

Modern observations

Tom Lorenzin

Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "10.6M; 9'x 5' extent; barred spiral with very bright nucleus; photo at HAG-46; 80' to NNW is SP GAL N1079 (12.5M; 1.5'x 1' extent) soft, silvery oblong with brighter center; look for 14M EL GAL N1097a, very soft and small (<1' diameter) about 4' NNW of N1097's core."

Clarke, W.P. (1992)

William P. Clarke (San Diego, California, USA) writes in The Webb Society Nebulae and Clusters Section Report No. 10, July 1992: "Highly elongated galaxy with a bright nucleus and a second bright region to one side, probably the small companion galaxy. (21-inch f/20, x140)."

Steve Coe

Steve Coe, observing with a 13" f/5.6, notes: "Pretty faint, pretty large, somewhat elongated and somewhat brighter in the middle at 135X in my old 17.5 inch Dobsonian. Using my 13" f/5.6 at 135X it was pretty bright, pretty large, much elongated 3 X 1 in PA 135 and much brighter in the middle."

Steve Gottlieb

02 46.3 -30 16 17.5: very bright, very large, very elongated NW-SE, very bright core. A companion galaxy N1097A is attached at the NW end.

8: bright, elongated NW-SE, bright core.

Polakis, Tom (newsgroup posting)

From: Tom Polakis (polakis@sprintmail.com)

Newsgroups: sci.astro.amateur

Subject: NGC 1097 Observations?

Date: Tue, 27 Jan 1998 23:18:54 -0700

While processing the latest batch of CCD images, I was impressed by the inner structure of NGC 1097, a barred spiral galaxy in Fornax. The Digital Sky Survey image shows the classic form, with a bar about 5' long leading to curved arms. My backyard CCD image barely shows these arms over the noise of the city sky. Much more interesting, though, is the 'spiral within a spiral' in the 40-arcsecond disc of the core. The image may be seen at http://www.psiaz.com/polakis/ccd/gx/n1097.jpg.

My impression before going out into the field to observe it was that the outer arms would be difficult, and the inner structure spectacular. The object yielded the opposite result. Using a 20-inch at a dark desert site, the outer arms were quite visible even to a novice observer. The bright inner spiral was only a bright, mottled disc. This detail may be more seeing dependent than anything -- sort of like looking for detail on Jupiter. Despite great transparency, the seeing was no better than 3 or 4 arcseconds on the night of my observation.

Luginbuhl and Skiff mention a faint stellar nucleus surrounded by a small oval core, 35" across. They saw this detail in 6-inch and 10-inch telescopes. I'm looking forward to another look at NGC 1097 on a steadier night. I'd be interested to hear about any other observations of the inner region of this galaxy.

Tom

Photo index

by Jim Lucyk: Sky&Tel. 9/83 p209, Deep Sky #13 Wi85 p34, Burnhams V2 p904, Vehrenberg's Atlas of DS Splendors (3ed) p46, Hubble Atl.of Gal. (Sandage 1961) p46, Universe Guide to Stars & Planets (Ridpath & Tirion) p144, Cat.of South.Peculiar Gal.and Ass. Vol 2 (Arp&Madore, 1987) p1.3.

Brian Skiff

NGC: pa151.

POSS: bar in pa147. located ~15' NNE of triangle of *s 4' on-a-side. no consp spot 1/2' SE, but * 1'.5 NW is real. S arm curves W, N arm E. M-5-7-22 = N1097A is 3'.3 NW.

6cm - pretty easy. well concen, 4'x1'.5, elong SE-NW. br non*ar center. found 20' N of triangle of *s of un= britness 4' across.

15cm - 3'x1' in pa135. core vsm oval w/f *ar nuc. vthin, sharp-tapered halo.

- big vbr gx elong in pa150 @ 50x/80x. 6'.5x4' w/wk broad concen in halo, then vstrong even in 30" circ core, which rises to non*ar nuc. nr NW end is m13.5 * that T&B chart shows as knot; m14.2 * closer in NW side W of maj axs. 3'x0'.5 bar prominent w/averted vis. BS, 15Nov1933, LCO.

25cm - 4'x0'.75 in pa130. core 0'.6 across, nrly circ, sometimes looking flattened, partic on N side. SE 0'.5 from center along maj axis is knot or *. 1'.5 NW of center, on S flank of halo is prob *, this one more noticeable than former spot.

30cm - br core w/losfcbr halo. 4'x1' up to 1'.8 wide in pa145. halo is narrow by the core, but on N and partic on S it feathers out to W. 220x: the *ar nuc is eccen, in NNE side of 50"x30" core. halo has lg-sizes irregs. core is perhaps in pa0. sketch in notes. CBL, 13 Oct1977, Roof.

Contemporary observations

Auke Slotegraaf

1997 November 28

1997 November 28/29, Fri/Sat: Jonkershoek, seeing 3, transparency 3, sky darkness 4, lim.mag. at south pole 6.0 (naked eye) Strong SE wind. "Just visible with averted vision as a round haze."

Magda Streicher

(no date)

12-inch f/10 SCT, 16-inch f/10 SCT (127x, 290x)

Elongated and diffused extending from the northwest to southeast, with a bright bar shaped nucleus. Flimsy sides steaming outwards in misty surroundings with just a few hints of dark areas. It appears brighter to the northwestern region. With averted vision an 11th magnitude double situated about 6' arc minutes to the east of the galaxy (218x). A lovely yellow 7 magnitude star about 13' arc minutes is visible slightly south. A fine and neat galaxy, share the field of view with a few outstanding stars. I could not confirm 1097A but with averted vision I think I just glimpse a hazy patch. A supernova was found in this galaxy on 12th October 1992.

16-inch S/C 127x, 290x. Lovely large soft cloud slightly elongated in a NW-SE direction. A tri-angle of stars is south of the galaxy. Between this tri-angle and the galaxy I could see the sling going out to the SW. This spiral arm is been well define between the arm and the galaxy north. I could make out the soft wimps of spiral arms going SE to NW. More or less 3.5x1.5. show off a envelope with uneven core. (Mag = 9.2; size 10.0' x 6.3'; SB 13.6v; PA 141 deg.)

Tom Bryant

2010 11 6 23:4:8

Observing site: Fall Star Party

Telescope: C-11

[2h 46m 18s, -30° 17' 0"] A bright nucleus, elongated 1:1.5 surrounded by a faint halo, elongated 1:6. An edge on spiral? Wikisky: A barred spiral, with a bright bar and faint arms. B:SBb.

Richard Ford

2012 February 18, Sat

Location:Perdeberg.

Instrument:12-Inch Dobsonian Reflector Telescope.

Time:11:28.

Sky Conditions:The fainter parts of the Milky Way are barely visible.

Transparency Of the Sky:Haziness only visible on the horizon.

Seeing:Atmosphere stable with little interference.

This bright galaxy's faint barred spiral arms are plainly visible at both 57* and 75*.This galaxy's is well condensed and equally bright in the center.Its spiral arms also has an elongated structure.The nucleus of this galaxy grows brighter compared to the spiral arms of this galaxy.

It measures 8.2'*2.7'.

Challenge Rating:Difficult.