NGC 6221

Remarks

Three large obscured spirals at low galactic latitudes in Ara – NGC 6300 and the pair NGC 6215/6221 – may be the brighter members of a loose group partly hidden by the absorption belt; the pair of late-type spirals IC 4710 and IC 4713, and perhaps IC 4662A and IC 4714 are other possible members. The large, low-velocity Magellanic irregular IC 4662 is clearly in the foreground. The length of the chain is 10°

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. His recorded it as "pretty faint, large, round, gradually a little brighter in the middle, 80 arcsec across." When he observed it a second time, he mistook it for a globular cluster, describing it as "globular cluster, pretty bright, pretty large, round, gradually brighter in the middle, 2.5' across, barely resolvable." His third observation was no more successful: "globular cluster, viewed in place, but clouded over before any description could be made."

Published comments

Hinks, A.R. (1911)

Hinks, A. R. (1911) On the galactic distribution of gaseous nebulae and of star clusters. MNRAS, 71(8), 693-701.

p 697: The only difficulty in discussing the distribution of globular clusters arises from the fact that some of the objects described in the NGC as globular clusters are really spiral nebulae. Prof Bohlin has called attention to this .. and gives as an instance: NGC 628 = M74, which is described by Rosse, and photographed by Roberts (vol ii,. p 67) and by Keeler (Crossley, plate 4) as a fine spiral, though in the NGC it is described as a globular cluster.

Two other instances are NGC 6221 and NGC 6412, both of which are really spirals."

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.

NGC 6300 Group:

Three large obscured spirals at low galactic latitudes in Ara – NGC 6300 and the pair NGC 6215/6221 – may be the brighter members of a loose group partly hidden by the absorption belt; the pair of late-type spirals IC 4710 and IC 4713, and perhaps IC 4662A and IC 4714 are other possible members. The large, low-velocity Magellanic irregular IC 4662 is clearly in the foreground. The length of the chain is 10°

Charlier, C.V.L. (1931)

Charlier, C V L (1931) "Stellar clusters and related celestial phaenomena", Lund Annals 2, 14, No. 19. Charlier examined prints from the Franklink-Adams atlas; "Table 6 gives a list of those objects in Bailey's catalogue for which the globular character is uncertain or not probable..."

NGC 6221 Remarks: "* inv in neb, n r B *"

Laustsen, S., Madsen, C. & West, R.M. (1987)

Exploring the Southern Sky: A pictorial atlas from the European Southern Observatory. Springer-Verlag.

Scanned image on disk. [1987EtSS.........0L], plate 29.

de Vaucouleurs, G. (1956)

"Survey of bright galaxies south of -35° declination", Mem. Mount Stromlo, No. 13. (photographic study, plates taken with the 30-inch Reynolds reflector, 20-inch diaphragm).

Sulentic & Tifft (1973)

(Sulentic and Tifft 1973) notes that this is a 11.5 mag galaxy.

Page, Thornton (1975)

("Galaxies and the Universe", Chapter 13 - Binary Galaxies) includes this galaxy in the NGC 6300 Group. Members include NGC 6300, NGC 6221, NGC 6215, NGC 6215A & IC 4662A. Possible members include IC 4710, IC 4713 & IC 4714.

Ryder & Dopita (1993)

Included in the CCD-atlas of Ryder S.D. & Dopita M.A. (1993) "An H-alpha Atlas of Nearby Southern Spiral Galaxies" Astrophys.J.Suppl. 88, 415. They note: "This unusual galaxy would no doubt be a lot more famous were it somewhat nearer and not so close to the Galactic equator. Optically, it is peculiar, with the northenr arm swinging back sharply and covering a full 180 degrees, while the southern arm barely gets started before fading out . . The bulk of the massive star formation in NGC 6221 is currently occuring in a supergiant complex just northeast of the nucleus, adjacent to the point where the southern arm joins the nuclear bulge . . NGC 6221 clearly needs more intensive study to understand the forces giving rise to the curious pattern of star formation in the disk."

Modern observations

ASV Journal (1971)

ASV Journal Vol 24 No 3 June 1971: "visible in 4-inch."

Contemporary observations

Magda Streicher

2006 May

Alldays

16-inch f/10 SCT (290x)

A very soft oval in a north to south direction. It grows lovely with averted vision the longer you look. Just barely get brighter to the middle. Strings of faint stars wraps around the western side of the galaxy.