h & chi Persei

NGC 869 (also known as h Persei) is an open cluster located 7.460 light years away in the constellation of Perseus. The cluster is about 14 million years old. It is the westernmost of the Double Cluster with NGC 884 (chi Persei). The clusters are visible with the unaided eye between the constellations of Perseus and Cassiopeia as a brighter patch in the winter Milky Way.

NGC 884 (top) and NGC 869 (bottom): double star cluster h & chi Per. Top right are the reddish filaments of IC 1805, star cluster Stock 2 is to the right (north) of  NGC 869 and open cluster NGC 663 is in the corner bottom right. North is to the right and East at top.

h & chi Per, Vorst (D), 30 Dec 2019, Canon EF 70-200 mm f/4 L USM telelens, Canon EOS 600D, 800 ISO, UV-IR, UHC filter, f = 131 mm,  stack of 35 exposures, each 30 sec, 1050 sec, PixInsight

h & chi Per, central part, cropped. Picture as above, PixInsight

During September 2021, I made some test runs with my new monochromatic CCD ASI1600mm pro. I used the L (luminance, UV-IR) filter, stacked 48 light frames (10 sec each). Unfortunately, no auto-guiding, but the individual exposures were sufficiently short. Bias, dark and flat frames were taken too. The ASI is, mainly due to its cooling, more sensitive than the Canon EOS, which can be seen comparing the Sep 2021 image with the previous ones.  Image processing was done using PixInsight V 1.8.8.-10.

h&chi Per, 04 September 2021, Kempen, William Optics APO 110 mm, f/7, L (UV-IR) filter, ASI1600mm pro,

gain 139, T = -10C, 520 sec. No auto-guiding. Image processing with PixInsight