Open cluster M37

About the object

M37, the richest of the three open clusters in Auriga: more than five hundred stars over an area half the Moon across, about three hundred million years old. An orange star, a red giant, marks the centre, surrounded by an even field of fine stars that gets the cluster compared to a handful of dust. In a telescope it is one of the prettiest clusters of the winter sky.

Distance: about 4,500 light-years, apparent size in the sky: ≈ 24′, constellation Auriga.

How it was shot

Everything here was shot with a DWARF Mini smart telescope from a balcony in a city in Ukraine: light-polluted sky, only the eastern half of it visible, and a roof overhang that cuts off the south. 1 night (in September), 1 session, 118 frames with exposures of 30 s, without a filter, in broadband. The stack holds 58 min of light. The goal for this object is 1 h, 96% done so far.

Open cluster M37 in the night log: 28 September.

How it went

One night of thirty-second frames without a filter. Of the three Auriga clusters this is the densest, and here the device shows its resolution limit: the fine stars in the centre start to merge. The orange giant in the middle stands out clearly. The goal is reached; a return is only worth it on a night of very steady air.