Backyard astronomy in the suburbs

STF 928, STT147 and a carbon star looking like burning red copper

On the 18th of March 2022 I aimed my telescope at Struve 928 in Aurigae. I cranked up the magnification to 83x, and I got a very pleasant surprise in my field of view. I got a split of the yellowish-white double STF928 with a separation of 3.5". In the same field of view to the south-east I saw another beautiful triple star, STT147. Thebright a-component looked deep yellow. But the real, unexpected showstopper for me was a star that looked like burning reddish copper. This proved to be the carbon star UU Aurigae. What a beauty! I am always amazed how beautiful these carbon stars are when seen visually through a telescope. UU AUR is of spectral type C6,3 and has a B-V index of about 3. Amazing beauty. On the sketch below, you see UU Aurigae as the bright orange-red stare on the right. The sketch was made ate the telescope on white paper with pencil. Later indoors the sketcht was digitalized in Affinity Pro. South is up an d east is to the right. The observation was made in a 150mm newtonian with a 9mm Morpheus eyepiece. Magnification is 83x and the field of view is 55'.

Collinder 72 (NGC1980)

Collinder 72 is a bright and very easy to locate open cluster, right beneath the Orion Nebula. The bright star Iota Orionis is the brightest star in the sword of Orion, and sits at the center of Collinder 72. At first glance, part of this cluster looks like the constellation Cepheus, but then a very small version of it. The little “house” pattern is easily visible. Collinder 72 is a poor cluster. There is no real central star, or colored stars in this small cluster. I see no glow of the nebula or unresolved stars. At the bottom left of the little Cepheus asterism I see a blue-white star, Iota or 44 Orionis. In fact this is a quadruple system, but I only see two components, Iota and at the south-east its fainter companion. To the southwest I see another double star, Struve 747. Here is a sketch I made on the 8th of February 2011 around 21:30 local time in my backyard in Landgraaf, Netherlands. The seeing was average (3 out of 5), the transparency was good (4 out of 5). The sketch was made with a 300mm dobson and a 12mm Nagler.

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