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.



IC 4591 (13,544 of 18,816)


oc gc pln bn dn gx gxcl ast aka lost




finder chart

altitude today

altitude (year)


½°, , in DOCdb

show browsing

IC 4591

IC 4591, Ced 127, DG 131, LBN 348.08+16.86, LBN 1096, Magakian 656

RA: 16h 12m 18s
Dec: −27° 55′ 40″

Con: Scorpius
Ch: MSA:1420, U2:335, SA:22

Ref: [2003A&A...399..141M], SIMBAD

(reference key)

Type: reflection nebula

Mag: B=?, V=?

Size: 11′ x 11′
PA: ?

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

IC 4591, IC 4592, IC 4601, IC 4603, IC 4604, and IC 4605 are all part of the great complex of nebulae around rho Ophiuchi in the general area of Antares. Though discovered visually by Barnard while he was sweeping for comets, the nebulae are too faint to be clearly seen by eye. So, Barnard's descriptions, published first in AN and a few months later -- with photographs -- in MN, come from his early Lick plates of the area. Interestingly, Stewart also examined a plate of the area, his taken from Harvard's Arequipa Station in Peru, but found only IC 4601 on it. His plate was a one-hour exposure, while Barnard was able to expose for two-plus hours with a faster camera for his discovery plates. Barnard's 6-inch portrait lens also gave a considerably larger field of view, roughly 12 deg by 10 deg (at least as reproduced in Vol. 11 of the Lick Publications). Stewart worked with a field of 6.4 x 6.4 degrees, coincidentally very close to that of the Palomar and Southern (Siding Spring) Sky Surveys.

Barnard's descriptions, while very sketchy and qualitative, are adequate to identify the nebulae, and his positions refer to the stars involved in the brighter parts of the nebulosity. Dreyer adopted generally adopted positions for the stars as given in Barnard's papers, so I've followed along using positions from Tycho-2 for the same stars. I've taken mean values when necessary.

Published comments

Cederblad, S. (1946) [VII/231]

Ced 127 (IC 4591)

Position (1900): RA 16 6.1, Dec - 27 40

Star: -27 10841 (Mp=4.53:, V=4.70, SpT=B3)

Spectrum of nebula: continuous spectrum (inferred from sp.t. of illuminating star)

Classification: Neb associated with mainly one star (which may be multiple) - star surrounded by a neb envelope without conspicuous structure (eg. lambda Scorpii)

Size: 23'x15'

Notes: "IC 4591. Disc. Barnard 1895 (61). (93 Pl 11 P1 13, 630 Pl 2). R. -27 10841 = HD 145482 = Boss 21778 = 13 (c2) Scorpii."

Lynds, B.T. (1962)

Lynds, B.T. (1962) Catalogue of dark nebulae. Astrophys.J.Suppl.Ser. 7, 1-52. [also: computer datafile: VII/7A]

Dorschner & Gürtler (1963)

Untersuchungen uber Reflexionsnebel.

DG 131

= IC 4591, Ced 127

Pos (1950.0) 16:09.2, −27:48

Size: 11x11 (blue), (not measured on red).

Magakian T. Yu. (2003)

= DG 131, IC4591, GN 16.09.2, Ced 127

Class: C (reflection neb)

Photo index

by Jim Lucyk: Vehrenberg's Atlas of Galactic Neb-2 p6.

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.