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NGC 7173 (16,987 of 18,816)


oc gc pln bn dn gx gxcl ast aka lost




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NGC 7173

NGC 7173, ESO 466-39, HCG 90c, LEDA 67878, MCG-05-52-008, SGC 215909-3212.9, UGCA 422, h 3909, GC 4730

RA: 22h 02m 3.38s
Dec: −31° 58′ 26.9″

Con: Piscis Austrinus
Ch: MSA:1404, U2:383, SA:23


(reference key)

Type: galaxy, E

Mag: B=13.05, V=?

Size: 1.38′ x 0.954′
PA: 143°

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A 12th magnitude galaxy, about 1' across, in Pisces Austrinus. Part of a tight bunch of three galaxies, NGC 7174 & NGC 7176. A fourth, more prominent galaxy, NGC 7172, is part of the quartet.

Historical observations

John Herschel (1847) Cape Observations

Discovered by Sir John Herschel at the Cape of Good Hope with an 18-inch f/13 speculum telescope. He recorded it as "B, vS, R, sbM to a star. The second of four." On a second occassion he called it "B, S, R, sbM." His third observation was recorded as "pF, R." The final record reads: "pB, S."

Burnham, S.W. (1894)

Publ.Lick.Obs. Volume 2. "Observations of Nebulae with the 36-inch Refractor of the Lick Observatory", p 168.

Noted, as was 7172, 7174 and 7176.

Published comments

Helwan Obs. Bulletin No 9 (1912)

A nebulous star.

Sandage (1975)

Sandage (1975(Astrophysical Journal, 202, 563-582) notes that this galaxy is a member of the NGC 7173 Quartet. Members include NGC 7173 and NGC 7176.

Helwan Obs. Bulletin No 22 (1921)

B, S, globular nebula. See HOB9.

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a 13.0 mag galaxy. Their coded description reads DBW/7176,CONT.

Modern observations

Bahr-Vollrath, Gerd (1993)

Gerd Bahr-Vollrath (Noosa Heads, Queensland, Australia) writes in the The Webb Society Nebulae and Clusters Section Report No. 11, January 1993: "[NGC 7172-3-4] A close trio of small, faint galaxies. All three appear as indistinct, faint glows. (8-inch f/12 SCT)"

Clarke, W.P. (1993)

William P. Clarke (San Diego, California, USA) writes in the The Webb Society Nebulae and Clusters Section Report No. 11, January 1993: "A group of four galaxies [NGC 7172, 7173, 7174 & NGC 7176] bunched together, the brightest being NGC 7172, which is the northernmost of the group. This object is extended E-W, with a bright nucleus. NGC 7173 is 3.4' south; it is nearly round and has a bright centre. NGC 7174 & 7176 are just S.f. NGC 7173; they are close enough together that their halos merge. Only the two bright nuclei allow them to be distinguished. (17.5-inch Newtonian, x227)"

Brian Skiff

15cm - N side of N7176 trio, 2nd brtst. 20" diam, circ w/sharp concen to br

*ar nuc. halo doesn't touch that of -76/74. BS, 15Nov1993, LCO.

Contemporary observations

Richard Ford

2011 October, 29th Saturday


Instrument:12-inch Dobsonian Reflector Telescope.

Sky Conditions:The fainter parts of the Milky Way galaxy are barely visible with the naked eye.

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

Seeing:Atmosphere stable with little interference.

Limiting Magnitude:4.9.

NGC 7173


Object Type:Galaxy.

First Impression:This object looks like a galaxy.

Location:Piscis Austrinus.


Chart Number:No.19(Extract taken out of "Atlas of the Night Sky").

Size:26mm Eyepiece:Field Of View:57'/15= 3.8'.

20mm Eyepiece:Field Of View:50'/13= 3.8'.

3.8'+ 3.8'= 7.6'.

7.6'/2= 3.8'.

Size in Arc Minutes:3.8'.


Major Axis:3.8'.

3.8'/3= 1.2'.

Minor Axis:1:2'.

Galaxy is 3.8'* 1.2'.

Brightness:Magnitude 11.8.

Brightness Profile:The galactic nucleus of this bright galaxy grows brighter compared to the central outskirts of it.

Challenge Rating:Very Difficult.



This elliptical galaxy has a roundish shape and is well defined.This galaxy is very faint and is seen as a smudge of light at 75*.I also noticed around the edges of this galaxy there are areas of uneven brightness.The galactic nucleus however of this galaxy is relatively compact.

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