Tag: Asterism

M40 Double Star

Messier 40 is a double star located in constellation Ursa Major (in the middle of the picture). Charles Messier was searching for the nebula in this part of the sky, which was observed by Johannes Hevelius. He was unable to locate any nebulous object, but he found this double star and catalogued them under the number 40. Double star should be a system of two stars, which are bonded by the gravity, but the latest measurements demonstrated that these two stars are close to each other only visually and they are completely unrelated.

Technical details:

TelescopeNewton 254/1000 mm
Aperture254 mm
Focal length1060 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
CameraZWO 071 Pro @-10°C
CorrectorExplore Scientific HR coma corrector
FiltersAstronomik L-1 - UV IR Block Filter
Exposure40x120s, Gain 94, bin 1x1,
Date2019-06-01

M73 Asterism of four stars

Messier73 is a group of stars (asterism), which are visually close to each other if viewed from Earth. M73 was discovered by Charles Messier on October 4 1780 and catalogued as an open cluster with some nebulosity. Latest investigation revealed that M73 is not a cluster, but just an asterism.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length660 mm
MountiOptron CEM25P
AutoguidingQHYCCD miniGuideScope 130 mm f/4.3, ZWO 174 MM
CameraZWO 071 Pro @-10C
CorrectorExplore Scientific HR coma corrector
FiltersAstronomik L-1 - UV IR Block Filter
Exposure75x180s, Gain 134, bin 1x1,
Date2018-09-04