sponsored by psychohistorian.org

DOCdb

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.

List:

log in to manage your observing lists

 browse:

 

 position:

 

 next:

 

 options:

summary

rename

prune

trim

remove

close

copy

combine

plan

bookmark

load

new

delete

marathon

favourite!

Full database:

Entire DOCdb database of 18,816 objects.

 browse:

 position:

NGC 247 (513 of 18,816)

 next:

oc gc pln bn dn gx gxcl ast aka lost

Object:

list

bookmark

finder chart

altitude today

altitude (year)

 search:

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

Black-Bottomed Galaxy

NGC 247, ESO 540-22, LEDA 2758, MCG-04-03-005, UGCA 11, Bennett 3, Caldwell 62, V 20, h 57, GC 132, Black-Bottomed Galaxy

RA: 00h 47m 8.6s
Dec: −20° 45′ 38″

Con: Cetus
Ch: MSA:340, U2:306, SA:18

Ref: SIMBAD

(reference key)

Type: galaxy (low surface brightness), SsD...

Mag: B=9.64, V=?

Size: 20.89′ x 5.37′
PA: 174°

Historical observations

William Herschel (c.1784)

Synonyms: H V-020

William Herschel observed it in 1784 with his newly completed 18.7-inch f/13 speculum telescope. He called it "a Streak of light about 27' long, and in the brightest part 3' or 4' broad. The extent is nearly in the meridian, or a little from S.p. to N.f. ... The situation is so low, that it would probably appear of much greater extent in a higher altitude."

John Herschel

Observations of Nebulae ... between the years 1825 and 1833

"eF; vL; vmE; vglbM; 10' long; pos 172.0 deg. Has no bright star in it, but a star 8.9mag at some distance n.p. [Sweep 293]"

Sweep 293 was conducted on 1830 September 16.

Ref: Observations of Nebulae and Clusters of Stars, made at Slough, with a Twenty-feet Reflector, between the years 1825 and 1833. [1833PTRS..123..359H]

Published comments

Helwan Obs. Bulletin No 9 (1912)

"F, 18' x 5', elongated spiral with many condensations. The existence of thirteen small nebulae discovered by Keeler in this region is confirmed, though most of them are too small and faint on the Helwan plates to confirm the details given about them, and Nos 8, 11, 12, and 22 cannot certainly be distinguished from stars. Nos 16 and 19 are probably spiral."

Burnham's Celestial Handbook

Burnham calls it a 10.7 mag spiral galaxy in Cetus, 18' x 5', "faint, extremely large, very much elongated, sudden nucleus." He notes that "in small telescopes, using low power wide-field oculars, it may be detected as a much-elongated smear of faint haze, oriented nearly north-south, with an extreme length of about 18'. .. Photographs show a very patchy and irregular distribution of star clouds in which the actual spiral pattern in only faintly recognized. A small bright central mass dominates the system. The northern quarter of the galaxy is occupied by a large dark oval area about 4.5' x 1.5, neatly enclosed by the loop of the system's northernmost spiral arm."

Van den Bergh (1963)

Van den Bergh ("A Nearby Cluster of Galaxies", Observatory, 83, December 1963, 257) derives the distance to the cluster as 2.0 Mpc, only about three times the distance to M31. Galaxies listed are NGC 45, 55, 247, 253, 300, 7793.

Photo index

Photo index by Jim Lucyk: Astronomy mag. 10/83 p57, Astronomy mag. 10/84 p78, Deep Sky #7 Su84 p23, Burnhams V1 p648, Vehrenberg's Atlas of DS Splendors (3ed) p21, Rev.Shapley-Ames Cat.of Bright Gal. (Sandage,Tammann 1981) p109.

Hodge, P.W. (1972)

Hodge, P.W. (1972) Some current studies of galaxies. Sky&Telescope, July, 23.

de Vaucouleurs, G. (1975)

de Vaucouleurs, G. (1975) Nearby groups of galaxies. In: Kuiper, G. (ed) Stars and Stellar Systems. Volume 9: Galaxies and the Universe. Chapter 14, p557.

[Sculptor Group is the] nearest of all nearby groups [and] is a loose association of six or seven late-type spirals Sc to Sm (NGC 45, 55, 247, 253, 300, 7793, and perhaps IC 5332)...

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a 10.0 mag galaxy. Their coded description reads LGES,BM,EL,DIF,VKN PD SSTR.

Sandage & Tammann (1975)

Sandage, A. & Tammann, G. A. (1975) Steps toward the Hubble constant. V - The Hubble constant from nearby galaxies and the regularity of the local velocity field. ApJ, 196, 313-328. [1975ApJ...196..313S]

Sandage and Tammann (1975, Astrophysical Journal, 196, 313-328) includes this galaxy in the South Polar Group. Members include NGC 24, NGC 45, NGC 55, NGC 247, NGC 253, NGC 300 & NGC 7793.

ESO/Upps (Lauberts 1982)

The ESO/Uppsala Survey of the ESO(B) Atlas remarks: "In foreground of cluster." The magnitude is given as 9.4.

Schmidt, K.-H. et al. (1993)

Schmidt K.-H., Priebe A. & Boller T. (1993) Nearby galaxies. Revised machine-readable version of the catalogue. Astron. Nachr., 314, 371. [1993AN....314..371S]

Other names: "UA11,E540-22". Inclination: (face-on, in degrees) 72 Total photoelectric blue mag 9.67 Total colour index .56 Logarithm of the angular diameter D25 (arcminutes) 2.33 Blue photographic magnitude 9.66 This galaxy is included in a sample of galaxies with velocity less than 500km/s with respect to the centroid of the Local Group. [Nearby Galaxies. Schmidt K.-H., Priebe A., Boller T. (Astron. Nachr. 314, 371 (1993))]

Arp, H. (1973)

North of NGC 247 lies the interacting galaxy known as the Burbidge Chain. (Arp, 1973, Ap.J., Vol 185, p797-808. fig. 3.)

Modern observations

Hartung, E.J. (1968) Astron.Obj.South.Tel

Hartung writes: "This large elliptical spiral nebula belongs to the Sculptor group . . . it lies in PA 175 as a long not bright ellipse about 15' x 3', rising broadly to the long axis with ill-defined centre. A fairly bright star is projected on the central line south-following. The lengthened form of the nebula is faint but definite with a 6-inch."

Sanford (1989) Observing the Constellations

Sanford says that this galaxy appears "as a large, faint stain on the sky with [a rich-field telescope], brighter toward the south. It is a large, nearby member of the South Galactic Pole group of galaxies, which includes NGC 45, NGC 55, NGC 247, NGC 253, NGC 300, and NGC 7793. This loose grouping has been characterized as the nearest group of galaxies there is beyond the Local Group, which is centred on our Milky Way Galaxy." Sanford notes that it "is seen at a high inclination, and has a curious darkening of the northern part, showing in photographs to be due to either a dark cloud of intervening matter or an area in the galaxy which has a low stellar density. There are several H II regions that are almost stellar in appearance and visible in large amateur telescopes. These are located at the north end, about half way down to the nucleus on the west side, with a group of 3 nebulae just south of the nucleus on the west side. There is a fairly bright star (probably of about 11th magnitude) at the southern limit of the galaxy, which is a foreground object. NGC 247 requires a clear, dark sky to be found, but is worth the search!"

Ancient City Astron.Club (1980)

Listed by the Herschel Club, described as "mag estimated 11, extremely elusive, elongated. Used averted visoin for this elusive galaxy, surface brightness is low. Try to find with binoculars, may stand out brighter as a whole. 8-inch, 43x and 10x50 binoc."

Walter Scott Houston

Houston calls this galaxy "huge, being about 21' by 7'. Though its total light is equal to a 9th mag star, the surface brightness is quite low due to the great size." In 1972 he wrote about observing from a mountaintop in Colorado with Everhart's 11.4-inch scope: "Because its light, though equivalent to a 9th mag star, is spread over a band about a quarter degree long, its surface brightness is low. Thus, even a trace of sky glow hides NGC 247."

Tom Lorenzin

Tom Lorenzin, in the electronic version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes "10M; 18'x 5' extent; oblique view of very large and faint galaxy; axis oriented N-S; 10M star embedded in S tip; many dimmer stars in and around; sketch their pattern for supernova hunting; about 3 degrees SSE of the Whale's tail: 2M Beta CET; good supernova prospect."

Steve Coe

Steve Coe, using a 13" f/5.6, notes: "Pretty faint, very large, much elongated (4 X 1) and has a star at one end. It is not much brighter in the middle at 100X in the 13". This object was much more conspicuous in my old 17.5" at 130X. In either scope, this galaxy has a pretty low surface brightness and does not deserve the 10th mag rating it gets in many listings. The outer portions are mottled in both scopes, with good seeing."

Brian Skiff

NGC: pa172.

RSA: * WSW 3'.1.

7cm - mod f, lg, modlosfcbr @ 30x, located in lg triangle of m9-10 *s. one of the m9 *s is nr S tip of halo. 50x: halo reaches a little past m9 * S and past top base of triangle to N, elong ratio 4:1. wk even concen, vf circ core 1' across. seems sl brtr overall S of center. m11 * on SW flank, has threshold * NW of it. BS, 26Nov1992, Anderson Mesa.

8cm - much fntr than N253 @ 20x, no cen concen. losfcbr spindle w/* on S tip. BS, 15Sep1982, Anderson Mesa.

15cm - vf, lg, extended. can't see much in dark locale. size 15'x3'.

- vlg fairly br gx of losfcbr @ 50x. 20'x5' in pa170: reaches 2' S of V=9.5 * (T&B) on S, where there us a knot marking the S end; goes at least 2/3 way N from V=10.8 * to m13 * N of it. V=12.2 * on SW flank marks outer width, m14 * N of it also good min axis indicator. wk broad concen, S end generally brtr though N half seems more extensive. various mottlings and vf knots vis@ 80x/140x. BS, 15Nov1993, LCO.

25cm - seen best @ 47x. elong pa170, 15'x3'. vlosfcbr w/o cen concentration. smooth texture. m10 * nr S tip. shape is spindle.

30cm - 149x: vlosfcbr, but concen core. on S limb is m9.5 * and 2' W is m10.5 *. core 2' across. hazy to * W. *s in S part of neb.

Contemporary observations

Auke Slotegraaf

2010 August 07/08, Sat/Sun

Karoo Star Party, Britstown, Northern Cape, ZA.

SQM-L 21.7

15x70 Celestron binoculars.

Readily seen in binocs as a very much elongated glow, oriented approximately north-south. A small star marks its southern tip (HD 4529, V=9.47). Lies near a large (3/4) bright (V~5.5) triangle of stars south of Diphda.

1992

A 10-inch f/5 at 30x under suburban skies shows this as a large, very elongated, oval smudge of light with a pretty bright star on its southern tip.

1997 November 28

1997 November 28, Tue/Wed: Jonkershoek, seeing 3, transparency 3, sky darkness 4, lim.mag. at south pole 6.0 (naked eye) "A challenging blur. Seen as a delicate smudge trailing northwards of a 9th mag star. Averted vision shows a small star just off the northern end. Galaxy extends for about 15 arcminutes, and with careful averted vision it ends near a small star to the east of the northern tip."

Magda Streicher

1997 November 20

Location: Pietersburg. ( South 23 53. East 29 28).

Sky conditions: Very good 7 magnitude.

Instrument: Meade 12 inch (Eyepiece super 40mm).

Date: 20 November 1997.

Field of view: 52.7 arc minutes.

Very faint large extended galaxy. Looks in a way elliptical to me with wisps of light around it. Even structure but low in surface brightness. A small star embedded towards the southern edge in this fine galaxy.

(no date)

8-inch f/10 SCT (EP: 1.25-inch 26mm SP 77x 41' fov; 1.25-inch 18mm SW 111x 36' fov)

Very faint, large extended north south galaxy, with a slightly bulging centre, and wisps of light around it. Faint mottled features begin to materialize although very hazy and low in surface brightness (111x). The northern part of this galaxy seems to be a little fainter than the southern part. A whitish star of about 9th magnitude is embedded toward the southern tip in this fine galaxy.

Richard Ford

2013 November 3rd, Sunday

Location:Perdeberg.

Time:12:53am.

Sky Conditions:The fainter parts of the Milky Way are barely visible.Haziness only visible on the horizon.Atmosphere stable with little interference.

Instrument:12-inch Dobsonian.

This spiral galaxy has both very faint extensions which are seen almost edge on as delicate whorls of soft light which has a grayish appearance at 57x and 75x.Around the edges of this galaxy there are plenty of areas of darkness being noticed.This galaxy measures 19.5'x 12.1'with P.A:N/S.

2010 August 7, Saturday

Location:Kambro Padstal,Britstown.

Instrument:12"Dobsonian Reflector Telescope.

Sky Conditions:Dark moon and stars magnitude 6 and fainter are barely visible with the naked eye.

Size: 14.2' x 1.4'.

P.A.:NE/SE.

Fairly easy to observe this galaxy in a dark sky away from city lights.

By observing this galaxy's, spiral-like structure is somewhat discerned where plenty of areas of uneven brightness is noticeable.I have found darker areas within this galaxy on the outskirts.I have also found a few faint bright stars near the galaxy.

Tom Bryant

2007-09-17 21:00:00

Observing site: Pinnacles overlook

Telescope: C-8

[0h 47m 6s, -20 46' 0"] A faint oval, smaller than NGC 253.

Favourite lists

Lacaille's catalogue

The Messier objects

Dunlop's catalogue

The Bennett objects

The Caldwell list

Named DSOs

Object search

First search phrase

    and

Second search phrase

Type of object to include:

open cluster
globular cluster
planetary nebula
bright nebula
dark nebula
galaxy
galaxy cluster
asterism & stars
unverified/lost
nova

The Bug Report

DOCdb is still in beta-release.

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

> Bug Report

Feedback

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

> Contact us

Help!

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.