Tag: Antares

Rho Ophiuchi region

Rho Ophiuchi is in my opinion the most beautiful assembly of the nebulae in the universe. Blue, red, and orange colors are combined to create this magnificent cloud complex. The dominant yellow star Antares (Alpha Scorpii) is a red supergiant, one of the largest visible stars. The star Alniyat (Sigma Scorpii) is surrounded by ionized hydrogen gas. Between these two stars is the M4 globular cluster, which I captured on Fuerteventura. The blue nebula is Rho Ophiuchi, also captured by me earlier.

In order to capture the whole beauty, one has to use a relatively short focal length (I used 180 mm), combined with a large sensor area (I used full frame 36×24 mm), and take the shots at a very dark location. This was my primary target during our trip to Crete 2021 and I am very happy that I finally got it framed. However, there is another beautiful nebula called Blue Horsehead in the visual vicinity and if I would turn the camera 90°, I would manage to capture it. So, there is a target for my next expedition.

Technical details:

LensAskar FMA180 F4.5
CameraCanon EOS 6Da
MountiOptron Skyguider Pro
Exposure38x120s, ISO 1600

M4 Globular cluster

Messier 4 (left side of the picture) is a globular cluster located in the constellation Scorpius, close to the brightest star of this constellation Antares (right side). This cluster is the closest one to the Solar System, due to its “short” distance of 7200 light-years and it contains several tens of thousands of stars. There is another globular cluster on the bottom side of the picture NGC 6144. The star Antares is classified as a red supergiant, with a diameter several times bigger than the Sun, which makes it one of the largest know stars. it is only 550 light-years away, which means M4 and Antares are close only visually, but in reality, there is a very long distance between them.
If any brighter star is photographed by the Newtonian telescope, the diffraction cross appears due to the so-called “spider vanes” holder of the secondary mirror. If the spider vanes are not perpendicular to each other (like in my case), the diffraction pattern makes multiple ugly lines. This means I will have to correct it, as soon as I get back from Fuerteventura.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
Exposure44x180s, Gain 94, bin 1x1,