Deep-sky dedication

Magda Streicher e-mail: [email protected]

Introduction Whenever I phoned Danie Overbeek, it was have known him. His words after my success answered with a brief identification “Danie” with asteroid Astrea still echo in my ears: at the other end, always followed with a note “You have not only m ade an observation, but of joy in his lovely deep voice and a friendly also a worthwhile scientific measurement, “Magda, it’s good to hear from you!” Danie well done!” Some of his last written words Overbeck was my motivation and inspiration were most appropriate: “1 shall now bow out for many and it was truly a privilege to gracefully.” Danie, we miss you.

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My observatory is situated in the North­ were first described by James Dunlop or ern Province, at latitude 23°53.9 South, lon­ , and I have found it interest­ gitude 29°28.3 Hast, just north of the Tropic ing to revisit these objects and compare my of Capricorn. The observatory is located far own observations. from any major metropolitan areas. Using 20cm and 30cm Schmidt-Cassegrain tele­ The Objects scopes this location enables me to do much I will describe the following twelve objects: useful deep-sky observing, which 1 have NGC 6826 Blinking in Cygnus done with great passion and satisfaction over NGC 1554/5 Hind’s Variable Nebula the past ten years. I have written up all my NGC 3228 cluster in observations, and wherever possible sket­ NGC 6204 cluster in Ara ched the objects for future study. With this NGC 5281 cluster in presentation I would like to show a sample NGC 4609 cluster in of my results, focusing on some more north­ NGC 4439 cluster in Crux ern objects and a few rarely known open NGC 272 asterism in Andromeda clusters, and urge other amateurs to develop NGC 1963 galaxy & asterism in Columba their own observing programs. NGC 2017 multiple in Lepus ‘Mini Coat Hanger’ asterism in UMi Selection of objects ‘Stargate' asterism in Corvus Firstly, 1 have opted for a discussion of some northern deep-sky objects, and though these NGC 6826 in Cygnus are not necessarily bright objects, they do Blinking , RA 19h 44.8 Dec have certain exceptional and unique charac­ +50° 31' teristics. Kach one can be described as spe­ Magnitude 9.8 and Size 2.3' cial and a challenge, especially when they Telescope: 8-inch Schmidt-Cassegrain f/10, are situated fairly close to the northern hori­ 26mm Super Plossl x77, fov40.6' and 18mm zon. Secondly I have opted for a few inter­ Super W ide x l 11, fov 36.2' esting clusters and asterisms. Many of these NGC 6826 is a fine bright green-bluish

James Dunlop Sir John Herschel Scotsman James Dunlop was bom on 31 Oc­ John Friedrich William Herschel, was bom tober 1793 at Dairy, near Glasgow, and 33 on 7 March 1792 at Slough near Windsor Cas­ years later found him in , at the eye­ tle, the only son of William. After revising piece of a 9-inch f/12 reflector searching the his father’s observations of the skies visible southern sky for nebulae and clusters. Dun­ from Slough, Herschel spent the years 1834- lop constructed the telescope himself, mak­ 1838 surveying the southern from the ing the mirror from burnished me (a I (specu­ Cape of Good Hope. He published a consol­ lum) using methods similar to Herschel. His idated catalogue of over five thousand nebu­ sky survey produced a catalogue of 629 ob­ lae and clusters. He died at his home in Kent jects, for which he was awarded the prestig­ on 11 May 1871 and was buried in Westmin­ ious Gold Medal of the Royal Astronomical ster Abbey. Society in February 1828.

141 june 2003 proceedings of the fifth symposium planetary a little elongated east-southeast and Hind’s Variable Nebula is a reflection/ west-northwest. The planetary displays a emission nebula associated with the varia­ non-stellar blob in the Milky Way with a ble star T Tauri. This 9.8 magnitude star has bright 10.6 magnitude central star. This beau­ a definite pinpoint appearance, with an ex­ tiful nebula certainly blinks as its name tremely famt, gentle north-south arc, close states. To the eye it brightens up to a star- to its western side. The nebula is somewhat like point just to fade out again like a hazy dimmer towards the centre, which explains patch o f light. The nebula exhibits a soft disk its two NGC numbers. Mr. Jan Hers indicat­ with a hint of an outer envelope. Mr. Mul- ed to me that the nebula was approximately laney indicates to stare directly at the centre 12.5 magnitude at the stated date in Febru­ of the star-like core of the planetary until the ary 1999. J.R. Hind discovered the nebula brightness overwhelm s the eye, and the neb­ in the 1852; it faded from view in 1868 ula disappears. However, using averted vi­ and did not reappear until 1890. sion, the nearby 9.5 magnitude star to the southwest suddenly reappears. Our Presi­ NGC 3228 Dunlop 386 in Vela dent, Tim Cooper, does not agree whole­ RA lOh 2 1.8 Dec -51° 43' heartedly with me but he nevertheless de­ Magnitude 6.0 and Size 18' scribed it as a fine object. Telescope: 12-inch Meade Schmidt-Casseg­ Steve Coe commented to look directly at rain f/10, 40mm Super Wide x76, fov 52.8' the planetary, the central star is prominent and 14mm Ultra Wide x218, fov 23.1' within the greenish nebulosity. Using avert­ An impressive small grouping of bright ed vision, the nebula appears brighter and stars with a distinctive formation that strong­ overwhelms the star. Alternating between ly reminds me of a daisy flower and stem. It direct and averted vision will produce a displays an overall brightness of approxi­ blinking on then off that is fascinating. There mately 6,b to 7th magnitude, unattached to are several other planetary nebulae that have each other and strongly defined against the the right central star to the nebula brightness background stars. Towards the south of this to show of this effect. little flower cluster with higher magnifica­ William Herschel discovered this plane­ tion, more fainter stars can be seen which tary in 1793. My fortunate position in South could be part of this whole cluster, giving it Africa has enabled me to easily locate the an elongated shape in another context. The nebula. The Blinking nebula is at declina­ cluster of approximately nine outstanding tion +50°; my most northerly objcct visible stars fills the middle section of my field of in the night sky is at +57". view in a north-south direction. Bright and outstanding just like a summer daisy in NGC 1554/5 in Taurus bloom. Hinds Nebula RA 04h 21.8 Dec +19° 32’ Magnitude when observed 12-13, Size 0.5' NGC 6204 Dunlop 442 in Ara Date: 14 February 1999 Open Cluster RA 16h 46.5 Dec -47° 01' Telescope: 8-inch Schmidt-Cassegrain f/10, Magnitude 8.2 and Size 5' 26mm Super Plossl x77, fov 40.6' and 18mm To me, one of the most outstanding com­ Super Wide xl 11, fov 36.2’ positions, two groupings can be seen. The

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group toward the cast is virtually a Jong er stars, form a gently curved line forming string, w hich drapes from north to south in a the shape of a cross. Only one star is a little perfect oval. Outstanding is the top bright askew from the almost perfect “cross”. This cluster contains about forty stars with the brightest star at 6.6 magnitude. Although NGC 5269 is situated twelve minutes to the west in a busy star-field, it could well be the one and same bright NGC 5281 cluster. John Hcrschel described it as a fine rich Milky Way group, or an outlying cluster of a much finer cluster following it.

NGC 4609 Dunlop 272 in Crux Open Cluster RA 12h42.3 Dec -62° 58' Magnitude 6.9, Size 5' The cluster lies in a starry part of the Coal Sack just northwest of the red­ dish magnitude 5 star HD 110432. Cluster looks like an artistic style impression of a comct. The star forms the nucleus and the star, situated in the south, and as the stars in cluster the tail to the northwest. The cluster the line progress they become fainter with members accompany the star, extend away the least faint one ending the line at the bot­ and spray out to the northwest forming an tom. Six fainter stars toward the eastern side irregular triangle. At both the south and represent a perfect question mark, with a northern end of the grouping lies a small tri­ faint star to the fullstop beneath it. angle of stars.

NGC’ 5281 Dunlop 273 Centaurus NGC 4439 Duniop 300 in Crux Open Cluster RA 13h 46.6 Dec -62° 54' Open Cluster RA 12h 28.4 Dec -60 06' Magnitude 5.9, size 5' Magnitude 8.0 and Size 4' Date: June 2000 and May 2002 Telescope: 12-inch Meade Schmidt-Casseg- Telescope: 8-inch Schmidt-Cassegrainf/10, rain f/10, 40mm Super Wide x76, fov 52.8’ 26mm Super Plossl x77, fov 40.6' and 18mm and 14mm Ultra Wide x218, fov 23.1' Super Wide x lII, fov 36.2' Approximately eleven stars resemble a Telescope: 12-inch Meade Schmidt-Casseg- dome-shape that is quite outstanding from rain f/10, 40mm Super Wide x76, fov 52.8’ that of the background star-field. Typical of and 14mm Ultra Wide x218, fov 23.1' Dunlop’s clusters, is the fact a few bright Mary FitzGerald once said, “Mr. Dunlop stars form star-strings of different shapes and certainly had a great fondness for strange forms. A nestles inside a dome small open clusters.” This cluster displays of half-moon stars. A comparatively bright an unusual “cross shape” appearance. Five 8“ magnitude star, just outside this cluster bright stars, along with another seven faint­ and towards the north, ends the star compo­

143 june 2003 proceedings of the fifth symposium sition. To my mind, the cluster reminds me is controversial, yet the star-slnng easily of the sickle emblem in the Russian flag. stands out to form a cluster. Hogg 14, situated about 18' to the north, Auke Slotegraaf says that he does not comprises a few faint stars with an overall know who originally described the galaxy brightness of magnitude 8.5. as NGC 1963. Initially, the thought was that such an object might have formed part of NGC 272 Asterism in Andromeda the Revised NGC. The coordinates are RA OOh 51.4 Dec +35° 50' roughly the same but NGC 1963 is obvious­ M agnitude 10, Size 4’ ly a cluster according to the description giv­ Date: Oetobcr 2001 en by John Herschel. The first ESO/Uppsa- Telescope: 8-inch Schmidt-Cassegrain f/10, la survey of the ESO(B) atlas indicated it to 26mm Super Plossl x77, fov 40.6' and 18mm be a cluster. The Reference Catalogue of Super Wide xl 11, fov 36.2' Galaxies did not list NGC 1963 at all. Prin­ Eight stars in an L-shape slightly out­ ciple Galaxy Catalogue noted an object la­ standing to the background star-ficld. Six of beled PGC 17433 as 1C 2 135, IC 2 136, NGC them display approximate 10 magnitude, 1963 and ESO 363-G to be the same object. while one comer of the L-shape is formed The Second Catalogue ESO 363-G7 noted by a 7 magnitude star and fainter compan­ IC 2135 and IC 2136 as the same object ac­ ion, probably a double star. It is more repre­ cording to Lewis Swift’s inscription. Mr sentative of a star-siring than a genuine star Swift, who was well acquainted with Her- cluster due (o its rather doubtful star duster scheJ’s work, was looking for new objects classification. that Herschel had overlooked. Swift there­ fore w ould have known NGC 1963 as a clus­ NGC 1963 Galaxy & asterism in Col ter. Whatever the case may be, it is inappro­ RA 5h 33.3m, Dec -36° 25’ priate to allocate the number NGC 1963 to a Telescope: 8-inch Schmidt-Cassegrain f/10, galaxy as it is obvious what Herschel saw 26mm Super PISssl x77, fov 40.6' and 18mm and described. Super Wide x 111, fov 36.2’ The coordinates o f this 13"' mag galaxy Telescope: 12-inch Meade Schmidt-Casseg- are RA 5h33m 12.7 and Dec -36°23'59" and rain f/10, 40mm Super Wide x76, fov 52.8' it is also known as IC 2135 and situated 12' and 14mm Ultra Wide x218, fov 23.1' toward the east of this cluster grouping. This string of stars appears like an arch- c t ’s bow. It is rather outstanding against the NGC 2017 multiple star in Lcpus background stars. Eight stars represent the RA5h 39.4, Dec-17° 51' handle o f the bow and another 6 distinct stars Magnitude: about 7, Size: 4.5' form the tip of the v-shaped arrow point. Telescope: 12-inch Meade Schmidt-Casseg­ John Herschel, the object’s discoverer, de­ rain f/10, 40mm Super Wide x76, fov 52.8' scribed it as a cluster o f stars about 8tl! to 11ril and 14mm Ultra Wide x218, fov 23.1' magnitude, arranged almost cxactly as a bow. Five stars with an unusual appearance The description of the star group suggests a stand out clearly against the background star- 13th magnitude galaxy towards the west, but field. With its variety of colours, it can truly I cannot confirm this. The galaxy NGC 1963 be described as one o f the most beautiful stel­

144 mnassa vol 62 nos 5 & 6 proceedings of the fifth symposium lar groupings J have ever seen. The bright­ defined composition of stars between 6,h to est 6.4 magnitude star has a very smooth 9"' m agnitude and well defined against a bare grey-blue colour. Towards the south of the star-f'ield. The two brightest stars in this primary is a yellow 8.8 magnitude star ac­ breathtaking composition display a golden companied by a smaller one. The 7.7 mag­ yellow colour. nitude star on the northern edge of the pri­ mary displays a strong orange colour. Fur­ Brief Description of my Observing ther westwards, a m uch smaller, slightly dirty Programs blue 8.2 magnitude star can be seen. These My studies of the deep-sky led me to be the stars seem to form a physically inter-related first to obtain the Deep-Sky Section’s Ben­ system. Hartung describes it as an: “Attrac­ nett Certificate. I am stiii involved with ob­ tive group of six stars, which show different servation of these objects, together with Jen­ colours of blue, yellow, orange and ash. ny Kay in Australia. 1 have also made an intensive study of Hcrschel’s non-existent Mini Coat Hanger asterism in UMi objects and the Dunlop Catalogue, and 1 con­ RA 16h 29.0 Dec+80° 15' tribute to the Webb Society and The Deep Magnitude: 9.5, Size: 14' Sky Magazine (Washington DC). Inbetween Date: May 2001, Portugal my deep-sky work I also contribute to the During my May 2001 visit to an Astro- Comet and Meteor, Double Star and Occul- Camp in Portugal I viewed and sketched this tation Sections of ASSA. northern objcct. In the northern hemisphere my hosts were not even aware of the mini Conclusion coat hanger when I showed this jewel to The foregoing demonstrates some of the use­ them. Compared very well with “older broth­ ful work that can be done on the deep sky er coat hanger” which can be found in Vul- by a dedicated amateur astronomer using pecula (Brocchi’s Cluster, Collinder 399). modest instruments under dark skies. I hope The mini star-string has a clear shape, which and trust that my humble contribution has appears from north to south and well defined assisted in revealing the wonders of the uni­ against the background star-field. There is a verse that unveils itself to us and that these faint 15.2 magnitude galaxy classified as results on some of my favorite objects will UGC 10447 and situated on the edge of the motivate others to try observing and record­ hanger’s neck, which I could not confirm. ing deep-sky objects and develop their own deep-sky dedication. Stargatc asterism in Corvus RA 12h 35.7 D ec-12° 00' M agnitude 6 -7, Size 8' Telescope: 8-inch Schmidt-Cassegrain 1710, 26mm Super Plossl x77, fov 40.6’ and i 8mm Super Wide xl 11, fov 36.2’ An almost pcrfect equilateral triangle of stars, nestle inside another almost perfect equilateral triangle of stars. An outstanding

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