Category: Open cluster

M67 Open cluster

Messier 67 is an open cluster located in constellation Cancer and it’s one of the oldest open cluster from Messier catalogue. Therefore it was examined by many scientific studies. The diameter of the cluster is approximately 20 light-years and it’s roughly 2700 light-years away from Earth.

Technical details:

TelescopeNewton 254/1000 mm
Aperture254 mm
Focal length1000 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
CameraZWO 071 Pro @-15°C
FiltersIR UV cut
Exposure25x180s, Gain 94, bin 1x1,


M50 Open cluster

M50 is an open cluster located in constellation Monoceros, visually not far from the brightest star Sirius. It was catalogued by Charles Messier in 1772 and it’s approximately 3000 light-years away from Earth. The latest research was conducted in 2012 and confirmed that the cluster contains 508 stars – you can try to count them.

Technical details

Telescope:Newton 254/1000 mm
Aperture:254 mm
Focal length:1000 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
Camera:ZWO ASI071MC Pro
Filters:UV IR cut

M26 Open cluster

Recently I purchased new travel telescope, the mount and the camera and I decided to make small comparison with my primary equipment. New equipment consist of iOptron CEM25P mount, which is very portable equatorial mount and small (6”) Ritchey–Chrétien telescope. Even the camera is new. ZWO 1600 MC has only 400 grams compared to the old Mii G2, which has 2.5 kg. The reason is that ZWO is color version without filter wheel, therefore narrow band imaging is not possible, but I will use this camera mainly under the darks skies. Detailed review of the portable setup will follow.

Back to the picture, I pointed the telescopes into the constellation Scutum and captured open cluster M26. This cluster is approximately 180 million years old and the light travelled 5400 years from there into my telescopes. The cluster is located in the plane of our home galaxy Milky Way; therefore there are so many stars in the background.

The upper picture was made by my primary setup – Gemini G35f, astrograph Newtonian 254/1000 with GPU coma corrector and MII G2 8300 camera. The lower picture is the outcome of the new setup: iOptron CEM25P, 154/1370 mm RC telescope with focal reducer Astro Physics CCDT67 and ZWO 1600 MC camera.

Technical details

Telescope:Newton 254/1000 mm
RC 154/1370
Aperture:254 mm
154 mm
Focal length:1000 mm
917 mm
MountGemini G53f
iOptron CEM25P
AutoguidingTS 60 mm, FL240 mm, ZWO 174 MM
Camera:Moravian instruments G2 8300M @-30C
ZWO 1600 MC @ -15C
Astro Physics CCDT67
Filters:Baader RGB
Exposure:10xL 180s bin 1x1, 8xRGB 120s bin2x2
28x 120s Gain 300

NGC6604 Open cluster

NGC6604 is an open cluster associated with nebulosity. It is located not far from my favorite Eagle nebula in constellation Serpens and it’s 5500 light-years far from the Earth. Since this deep space object is not that high on the skies, I rather used narrow band filters, because this part of the skies is strongly influenced by the light pollution, which is coming from the nearest town. First picture is processed in “fake” Hubble color palette, the second one should more or less look like in “true” color.

M48 Open Cluster

M48 is an open cluster discovered by Charles Messier in 1771. The cluster is located in constellation Hydra and it’s 1500 light-years far from the Earth. This cluster can be observed even by small binocular, but small telescope reveals more than 50 stars. During waiting for Sombrero galaxy I pointed my telescope just below bright star Procyon and collected some light coming from this cluster.

M44 Beehive Cluster

Beehive cluster is an open cluster located in constellation Cancer. Because of its relatively “short” distance to the Solar system (600 Light years), it didn’t fit fully into the field of view of my telescope. The cluster has approximately 1000 stars and even two planets were discovered there.

NGC7380 Wizard nebula

Wizard nebula is an open cluster associated with nebulosity.  Visually, it has apparent size of the full Moon, but since it’s very far from the Earth (7200 light years), its real diameter is about 100 light years.

So, where is the wizard located? It took me a while to find him, but if you turn your head 90° counter-clockwise, you see two darker hands. It looks like he is trying to grab something. Then above the hands you see the wizard’s conical hat.

First picture is a composition of 3 narrow band pictures (Ha, OIII and SII) and composed in Hubble Space Telescope palette. Second one is more-or less visible spectrum.

ngc7380-wizard-2016-10-06-30c-600s-32x-haoiiisii-fl1000-dbe-proc ngc7380-wizard-2016-10-06-30c-600s-32x-haoiiisii-fl1000-dbe-rgbeq

M39 Open cluster

My god, it is full of stars! I think everybody knows this sentence and if not, you should watch probably the best movie from Stanley Kubrick 2001: A Space Odyssey (1968). Anyway, my reaction when I processed this image was the same just like David Bowman, when he was traveling through the star gate created by the monolith orbiting the Jupiter. The reason why there are so many stars in the background is simple. M39 is an open cluster located in not far from constellation Cygnus (Swan). This constellation is lying on the plane of our home galaxy Milky Way, therefore we are now looking through the galactic disk.


M29 Open Cluster

M29 is an open cluster located in constellation Cygnus (Swan) and it’s approximately 6000 light-years from the Earth. It can be observed even by the binoculars or small telescope.

M52 Open cluster

M52 open cluster was discovered catalogued by Charles Messier in 1774, from there stands the “M” letter. It’s located in constellation Cassiopeia and it’s visible even by small binocular.


M11 Wild Duck Cluster

Wild Duck Cluster is one of the biggest known open star cluster. It’s located in constellation Aquila (Eagle), it contains approximately 2900 stars (you can count them on the picture) and it’s very far – 5500 light years from the Solar system. The name “Wild Duck” comes from the observation of Admiral Smyth – he saw wedge-shape group of stars. I don’t know about you, but I don’t see any V-shape formation, maybe Admiral Smyth was observing during very cold night and tried to warm up by grog or something.

M11 Wild Duck Cluster

Open clusters

Open clusters are small groups of stars, which are bonded together by the gravitational forces. They contain significantly fewer members and are younger compared to globular clusters. Open clusters were probably formed from giant clouds of interstellar gas and dust. In many nebulae, the formation of new stars is still happening and we can witness the formation of new open clusters.

M45 Pleiades

Probably the most famous open cluster, visible by naked eyes is called Pleiades, Subaru or Seven Sisters. Charles Messier cataloged this DSO under number 45 (M45). This cluster is located in constellation Taurus. It’s the closest cluster to the Solar system (430 light years), has 8 light year in diameter and it’s characterized by the nebulosity – reflective illumination of the space dust by the blue light of the hot, young stars. The brightest stars have names: Alcyone, Atlas, Electra, Maia, Merope, Taygeta, Pleione, Celaeno and Sterope.

M45 Pleiades