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 years and it was truly a privilege to gracefully.” Danie, we miss you. 140 mnassa vol 62 nos 5 & 6 proceedings of the fifth symposium My observatory is situated in the North­ were first described by James Dunlop or ern Province, at latitude 23°53.9 South, lon­ John Herschel, 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 nebula 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 Vela observations, and wherever possible sket­ NGC 6204 cluster in Ara ched the objects for future study. With this NGC 5281 cluster in Centaurus presentation I would like to show a sample NGC 4609 cluster in Crux 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 star 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 Planetary Nebula, 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 Australia, 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 stars 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 year 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 Open Cluster 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 declination +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 142 mnassa vol 62 nos 5 & 6 proceedings of the fifth symposium 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 dark nebula 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.