Tag: Explore scientific coma corrector

M73 Asterism of four stars

September 4, 2018
Asterism
1 Comment

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

M30 Globular Cluster

September 3, 2018
Globular cluster
1 Comment

Messier 30 is a globular cluster located in constellation Capricornus. Compared to recently captured globular clusters there are not so many stars in the background. M30 is about 27’100 light-years far from Earth, has 93 light-year in diameter and it contains approximately 150’000 stars.

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
Exposure60x180s, Gain 134, bin 1x1,
Date2018-09-03

 

M6 Butterfly cluster

September 3, 2018
Open cluster
1 Comment

M6 is an open cluster located in constellation Scorpius. Visually it’s located not far from horizon, at least from Central Europe; therefore it’s hard to capture this deep space object. The observing/capturing conditions change significantly if you travel to Southern Europe. From there the cluster is visible by naked eye. The stars from similar shape to butterfly, therefore  it got its name. On the bottom side of the cluster is nicely visible red giant (orange star) called BM Scorpii. The background illuminates the Milky Way.

The picture was taken during chasing darkness on Greek island Milos and in total was taken 30 pictures having exposure 180 seconds, i.e. total 90 minutes of integration.

Technical details:

Telescope:Newton 150/600 mm
Aperture:150 mm
Focal length:660 mm
MountiOptron CEM25P
AutoguidingQHYCCD miniGuideScope 130 mm f/4.3, ZWO 174 MM
Camera:ZWO 071 Pro @-10C
Corrector:Explore Scientific HR coma corrector
Filters:Astronomik L-1 - UV IR Block Filter
Exposure30x180s, Gain 134, bin 1x1,
Date:2018-09-03

 

M9 Globular Cluster

September 3, 2018
Globular cluster
1 Comment

Messier 9 is a globular cluster located in constellation Ophiuchus. Particularly interesting is, that it’s surrounded by a dark cloud, which is called Barnard 64. Also interesting is the fact that this cluster is one of the nearest globular clusters to the center of our galaxy.

The picture was taken on island Milos by integration of 24 picture each 120s, which means only 48 minutes in total.

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
Exposure24x120s, Gain 134, bin 1x1,
Date2018-09-03

M75 Globular Cluster

September 3, 2018
Globular cluster
1 Comment

Messier75 is a globular cluster located in the constellation Sagittarius.  It is approximately 67’500 light-years away and is has diameter 134 light-years.

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
Exposure19x180s, Gain 134, bin 1x1,
Date2018-09-03

M8 Lagoon Nebula

September 1, 2018
H II nebula
1 Comment

Lagoon nebula (sometimes called Messier 8) is a giant intergalactic cloud of ionized Hydrogen. The nebula is located in constellation Sagittarius and it’s 4100 light-years away from Solar System. It belongs to one of the brightest nebulas visible from northern hemisphere.

I have to admit, this nebula was the main reason and target of the trip to Milos and it was the first deep space object captured there. When I processed the picture I was so happy that the nebulosity is so clearly visible without any narrow band filters. Well, mission accomplished.

Technical details:

Telescope:Newton 150/600 mm
Aperture:150 mm
Focal length:660 mm
MountiOptron CEM25P
AutoguidingQHYCCD miniGuideScope 130 mm f/4.3, ZWO 174 MM
Camera:ZWO 071 Pro @-10C
Corrector:Explore Scientific HR coma corrector
Filters:Astronomik L-1 - UV IR Block Filter
Exposure39x180s, Gain 134, bin 1x1,
Date:2018-09-01

M3 Globular cluster

June 10, 2018
Globular cluster
0 Comment

Finally there was a nice weather and no Moon. Summer nights are short; therefore it’s not optimal for deep space objects, which require very long integration time. Therefore I pointed my telescope this evening to globular cluster M3.

This cluster is located in constellation Canes Venatici and it’s one of the largest known clusters, because it contains around 500 000 stars.

Technical details:

Telescope:Newton 254/1000 mm
Aperture:254 mm
Focal length:1000 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
Camera:Mii G2 8300
Corrector:Explore scientific CC
Filters:Baader LRGB
Exposure:16xL 180s bin 1x1, 8xRGB 120s bin 2x2
Date:2018-06-10

M14 Globular Cluster

June 10, 2018
Globular cluster
0 Comment

Messier 14 is a globular cluster located in constellation Ophiuchus. The cluster has diameter 100 light-years, contains several hundred thousand stars and it is approximately 30 thousand light-years far from us.

The picture is a stack of 20 luminance frames, each 3 minutes long and 6 RGB frames per channel.

Technical details:

Telescope:Newton 254/1000 mm
Aperture:254 mm
Focal length:1000 mm
MountGemini GF53f
AutoguidingZWO 174MM, TS 60/240 mm
Camera:Moravian instruments G2 8300M @-30C
Corrector:Explore Scientific HR coma corrector
Filters:Baader LRGB
Exposure:20xL 180 s bin 1x1, 6RGB, 120s, bin 2x2
Date:2018-0610

Worldwide coma correction exercise

April 5, 2017
Hardware
86 Comments

Introduction

What is coma and why needs to be corrected. Coma is a special type of an optical aberration. It’s mainly visible in the astrophotography – the stars are deformed into comet-like shapes:

Fast Newtonian telescopes suffer from comatic aberration, mainly in the corners of the photos. These telescopes are nowadays very popular between amateur astrophotographers just like me, because they offer the best price/aperture ratio. There is easy way how to suppress the comatic aberration – coma correctors. There are many coma correctors on the market, but there are just a few published reviews or comparisons between them. Therefore I decided to perform the comparison myself. Quite big collection of coma correctors has assembled in my drawer ready to be tested:

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