Observing weekend at Leeuwenboschfontein

posted: 639 days ago, on Monday, 2016 Mar 14 at 03:48
tags: astronomy, deep sky, observing report, SQM, astrophotography, Leeuwenboschfontein.

Leeuwenboschfontein is a lovely guest farm in the Klein Karoo, north of the Waboomsberge in the Nouga Hills (midway between Touws River & Robertson). It is an easy drive; head on to the N1 from Cape Town; 21km before Touws River, take the R 318 and drive south for 27 km to a gravel road turnoff. About 11km later you're there; your GPS should then read 33 34′ 00 S, 19 59′ 08 E.

Heading south on the R 318

Gravel road to Leeuwenboschfontein

Our group consisted of Ed & Lynnette Foster, Alan & Rose Cassells, Louis Fourie, Iain Finlay, Willem van Zyl, Barry & Miems Dumas. The guests of honour were ⁠⁠⁠⁠⁠Klaas van Ditzhuyzen and his charming companion Wilna. Klaas is an accomplished astrophotographer, a well-travelled astronomer, and a knowledgeable chemist (amongst other things!) from the Netherlands.

Visit Klaas' website, northsouthsky.com, for a glimpse into his fascinating life, which includes a report about this weekend.

Our first evening, Friday March 04, was an observing joy. SQML-L readings ranged over 21.54+/-0.00 and 21.68+/-0.03, and the seeing was very good. I spent a few hours binocular observing, and taking unguided wide-angle astrophotos.

Two memorable clusters, always well worth a closer look, are NGC 6208 and IC 4651. The duo are located in Ara, a lovely area to sweep with the relatively high-powered Celestron 17x50 binoculars. The black background is punctuated by a wealth of white star sparkles, some with a hint of colour (like zeta and epsilon-1 Arae). "Behind" the stars the ground of the Milky Way is uneven, with tracts of irregular black regions intermingled with barely perceptable glowing patches. Nudging the binoculars "up" (or just 1.5 west) from epsilon-1 Arae reveals a well-isolated feature within the very rich star field. This is NGC 6208, a large nebulous puff of light, at first round in shape but upon study very slightly elongated NE-SW. With some concentration it may be mottled, but not certainly so. Nearby epsilon-1 and epsilon-2 Arae are handy for estimating its size: about 13-arcmin. [1/3 to 1/2 of the separation between the two stars.] NGC 6208 is easy to locate; it lies at the western corner of an isoceles triangle with zeta and epsilon-1 Arae, 2.6 distant from zeta. John Herschel's description is spot-on: "A pretty insulated milky way cluster...".

Nearby IC 4651 is a gorgeous open cluster, beautifully positioned in a bright Milky Way field. It is difficult to avoid comparing it to NGC 6208: for one, IC 4651 is brighter than NGC 6208, breaking the "rule" that IC objects are fainter than NGCs. Secondly, the two clusters share a congruent placing: IC 4651 lies at one tip of an isosceles triangle with two bright stars, alpha and kappa Arae (1 west of alpha). Binoculars show it easily, appearing as a large, approximately round nebula, about 10' across, which is prominently mottled. A curious visual feature is the impression of an off-centre halo. The obvious part of the cluster is the brighter, roughly round figure, which seems to have a faint crescent rim to the south-west (as if an offset fainter cluster lies behind it).

Louis and myself spent some time together, drinking coffee, staring agog at Saturn, and enjoying high-power views of the blue/green/gray/tan-coloured NGC 3242, the Ghost of Jupiter. After moonrise, Louis posed for a photo with his C14, and we ended our session just after 04:00.

Louis Fourie at the eyepiece of his C14, with the Moon rising below the Milky Way.

2016.03.05, 02:46 SAST. EOS 60D, 10-mm f/3.5, ISO 3200, 17x 44-s frames. No darks.

Socializing

After the perfect condition of the first night, clouds and drizzle prevailed, giving us an excellent opportunity to relax around a braai fire.

Iain, Willem, Alan, Rose, Lynnette, Ed, Louis, Klaas, Barry.

Ed & Lynnette

Barry and Miems

'n Leeu en 'n bos.

Miems & Wilna, with Barry & Klaas in the middle-ground. Back ltr are Willem, Alan, Rose, Lynnette, Ed & Louis.

nothing more to see. please move along.