sponsored by psychohistorian.org


Deep Sky Observer's Companion – the online database


Welcome, guest!

If you've already registered, please log in,

or register an observer profile for added functionality.


log in to manage your observing lists























Full database:

Entire DOCdb database of 18,816 objects.



NGC 7578 (17,706 of 18,816)


oc gc pln bn dn gx gxcl ast aka lost




finder chart

altitude today

altitude (year)


½°, , in DOCdb

Warning: date(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected the timezone 'UTC' for now, but please set date.timezone to select your timezone. in /home/yivumoo/public_html/show_object.php on line 167

show browsing

NGC 7578

NGC 7578, NGC 7578B, LEDA 70934, MCG+03-59-025, UGC 12478, VV 181a, Arp 170, HCG 94a, III 182, h 2225, GC 4926

RA: 23h 17m 13.62s
Dec: +18° 42′ 28.4″

Con: Pegasus
Ch: MSA:1209, U2:169, SA:9


(reference key)

Type: galaxies (interacting), E

Mag: B=15, V=?

Size: 2.123′ x 1.614′
PA: 30°

History and Accurate Positions for the NGC/IC Objects (Corwin 2004)

NGC 7578. The modern catalogues make a small mess of this NGC number, so here are the facts in RA order (the positions are from HKA):

RA (1950.0) Dec Hickson VV UGC RC2/3 23 14 42.50 +18 25 39.5 94b=N7578A 181b 12477=N7578a N7578A 23 14 44.00 +18 26 04.4 94a=N7578B 181a 12478=N7578b N7578B

Hickson and VV did things logically (by magnitude), choosing the brightest component as "a". UGC followed its internal scheme, also logical, of choosing component letters by RA. RC2/3 followed UGC.

Looking at the NGC, we see that N7578 was only observed by William and John Herschel. Though WH noted "4 or 5 small stars with nebulosity," JH saw only one object here which he succinctly described with a single letter "F." Neither of their positions is good enough to pin down one or the other of the galaxies as the real N7578, but since Hickson 94a is brighter by over 0.6 mag, I think that we can choose it as N7578 without bending the history too much.

So, I have ignored the NGC identifications in Hickson, UGC, and RC2/3; and have made the brighter north-following object (UGC 12478) = NGC 7578.

This group, buy the way, may also be NGC 7571, which see.

Historical observations

William Herschel (c.1784)

Synonyms: H III-182

Discovered in 1784 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "4 or 5 small stars with nebulosity. 240 left doubt."

Published comments

Arp (1966)

Listed as No. 170 in Arp's "Atlas of Peculiar Galaxies" (Astrophysical Journal Supplement, vol. 14, 1966.)

Sulentic & Tifft (1973)

NGC 7578A: The RNGC (Sulentic and Tifft 1973) notes that this is a 15.0 mag galaxy. Their coded description reads STEL.

NGC 7578B: The RNGC (Sulentic and Tifft 1973) notes that this is a 15.0 mag galaxy. Their coded description reads STEL,INLGDIF NEB.

Favourite lists

Lacaille's catalogue

The Messier objects

Dunlop's catalogue

The Bennett objects

The Caldwell list

Named DSOs

Object search

First search phrase


Second search phrase

Type of object to include:

open cluster
globular cluster
planetary nebula
bright nebula
dark nebula
galaxy cluster
asterism & stars

The Bug Report

DOCdb is still in beta-release.

Known issues, feature requests, and updates on bug fixes, are here:

> Bug Report


Found a bug? Have a comment or suggestion to improve DOCdb? Please let us know!

> Contact us


DOCdb is a free online resource that exists to promote deep sky observing.

You could help by sharing your observations, writing an article, digitizing and proof-reading historical material, and more.

> Find out more

Everything on DOCdb.net is © 2004-2010 by Auke Slotegraaf, unless stated otherwise or if you can prove you have divine permission to use it. Before using material published here, please consult the Creative Commons Attribution-Non-Commercial-Share Alike 2.5 License. Some material on DOCdb is copyright the individual authors. If in doubt, don't reproduce. And that goes for having children, too. Please note that the recommended browser for DOCdb is Firefox 3.x. You may also get good results with K-Meleon. Good luck if you're using IE. A successful experience with other browsers, including Opera and Safari, may vary.