Flattener correcting the view field - Importance of working distance.

Flattener at a distance of 10mm from sensor showing clearly aberration at the edges.

I was not aware about the importance of distance from the flattener to the sensor. Below pictures show the difference. The picture with Messier M56 was taken with the flattener fixed at a distance of 10mm. This pictures shows clearly aberration at all edges.  The aberration is almost gone on the picture with M39. For this picture the flattener was located at a distance of 100mm.
According to the technical data the ideal working distance to the sensor is depended of the focal length of the refractor :

♦ focal length < 450 mm: 128 mm
♦ focal length 450-490 mm: 123 mm
♦ focal length 500-550 mm: 118 mm
♦ focal length 560-590 mm: 116 mm
♦ focal length 600-690 mm: 113 mm
♦ focal length 700-800 mm: 111 mm
♦ focal length ab 800 mm: 108 mm

An underrun or an overrun of the distance of up to 5% has no visible effect on the sharpness in the field of sensors with formats up to APS-C. With larger sensors, the tolerance is reduced to 1-2%.

Flattener 100mm - Picture is sharp at the edges

M39, NGC7082, Minkowsky M1-79, Platais 1

Looking into more details around Messier M39, I found beside Platais 1, also NGC7082 and the Planetary Nebula Minkowsky M1-79 of Magnitude 13.9.

Open Cluster M39 and Platais 1

In constellation Cygnus the open cluster M39 and the faint open cluster Platais 1 can be observed. The pictures are taken with Nikon D7500 and refractor TLAPO 80/480 f/6, each picture ISO2000 and 30s exposed. Stacking using deepskystacker and limited editing with CS4.

Globular Cluster Messier M2

Globular Cluster Messier M2 is the most compact cluster in the Messier group. It's located in the constellation Aquarius at a distance of 40.000 lightyears from Earth. The cluster counts more then 1.500.000 stars.
The pictures are taken with Nikon D7500 and refractor TLAPO 80/480 f/6, each ISO800 and 30s. The moon was 83% impacting brightness of the picture. Stacking with deepskystacker and limited editing using CS4.

Messier M17 Swan Nebula

Messier M17, also known as the Swan Nebula or The Omega Nebula is an emission Nebula located about 6000 light years from Earth. It is an action star forming region, the same as M42. M17 can be observerd in the constellation Sagittarius and is part of the Sagitarrius spiral arm of our own galaxy.
The pictures shows the Swan easily. The picture is the result of 18 exposures, stacked using Deepskystacker and editing using CS4.

Helios - ASH Polaris BBQ

Sterrenclubs Helios (Averbode) en ASH Polaris (Herentals) organiseerden een BBQ ter gelegenheid van de maansverduistering op de vliegterreinen van Schaffen. Met een prachtig uitzicht en de warme temperaturen werd het geweldige BBQ.

Ondertussen bezochten we ook het luchtschip (het "varken") dat onze militairen gebruiken voor opleiding van parachutisten.

Daarna werd het iets stiller want de bewolking zorgde ervoor dat de maansverduistering onzichtbaar bleef. Even was er een opflikkering waarbij de rode maan zich bloot gaf, maar het was maar tijdelijk. Dus hadden we voldoende tijd om wat bij te praten en de overgangen van Iridium flares en ISS te observeren.

Moon 87%

Temperatures during the day went up till 31°C, so nights are perfect to cool down and meanwhile taking pictures of the Moon. The Moon is 87% illuminated and the picture was taken using TAL200K with Nikon D7500. Limited editing using CS4.

M17 The Swan Nebula

The sky is bright due to a waxing moon (85%). So it was difficult to make observations of Deep Sky object. Below is a picture of M17, The Swan or Omega Nebula and M18, a open cluster.
No filters are used and no stacking. The single shot is edited using CS4.

Asterism STAR27 the Toadstool

Last night I took some time to search for asterism STAR27 in Delphinus. East of the Dolphin 13 stars make the asterism mushroom or toadstool.

Moon 71%

The Moon this evening, 71% illuminated and less then one week before the Lunar Eclips.

End of Astronomical Twilight

This weekend, it's the end of the Astronomical Twilight. The night will be dark again as the Sun will be below the horizon for more then 18°. So between 01h05 and 02h30 it should be dark enough to make your observations. Mars is the currently the brightest object of the night sky and can be seen low (14°) above the South-Eastern horizon.

Mars the Red Planet low above the South-Eastern Horizon

40000 Visitors Thank You

Counting 40.000 visitors for my Blog... Thank You :) 😂

Andromeda Galaxy M31, M32 and M110

Trying to optimize the results from pictures taken earlier this week. In total 48 pictures were taken eacht with an exposure time of 30s and ISO6400. I removed all pictures with "startrails" and stacked the remaining using Deepskystacker. The result is saved as Tiff16bit as this is the max. I can edit with CS4.

Nikon D7500 TLAPO 80/480 f/6 ISO6400 20minutes

The area of Sagittarius M20, M21, M22, M23 and M25

Some pictures made in the constellation Sagittarius :

Messier M20 - The Triffid Nebula; an emission nebula
Messier M21 - Open Cluster
Messier M22 - Globular Cluster
Messier M23 - Open Cluster
Messier M25 - Open Cluster

All pictures are taken with Nikon D7500 and refractor TLAPO 80/480 f/6 without filters.

Messier M29 Cooling Tower

Messier M29 (Cooling Tower) can be found in the constellation Cygnus and is located at a distance of 6000 light years from Earth.
Picture is taken with Nikon D7500 on refractor TLAPO 80/480 f/6 ISO3200 for 15s. No stacking.

Eastern Veil Nebula NGC6992

The Eastern Veil Nebula (NGC6992) is seen within the constellation Cygnus. Best observation with OIII filter but the picture below is without any filter.

Crescent Nebula NGC6888

In the constellation Cygnus we find the emission nebula "Crescent Nebula" (NGC6888). It's located at a distance of 5000 light years and can be best observed with OIII, UHC or H-alfa filters. For this picture  no filters are used. The picture is a combination of 4 frames, with a total exposure of 222s.

Dumbbell Nebula M27

The Dumbbell Nebula (Messier M27 - NGC 6853) is a Planetary Nebula located in the constellation Vulpecula. The Nebula is about 1300 light years away from Earth.
The picture is taken using NikonD7500 with refractor TLAPO 80/480 f/6.  Two frames, each 30s are stacked with Deepskystacker.

10 Days to go for the Lunar Eclipse

Counting down for the Lunar Eclipse which can be observed in Belgium and other parts of Europe. Crossing fingers for a cloud free evening sky :)

Andromeda Galaxy M31 M32 M110

Nikon D7500 TLAPO80/480 f/6 ISO6400 1200s

Andromeda Galaxy M31, M32 & M110

The Andromeda Galaxy M31, M32 and M110 was photographed using Nikon D7500 and TLAPO80/480 f/6 with settings ISO6400 and 30s exposure time. Stacking done with Deepskystacker and final editing using CS4.

104 Spotless Days & Limb Darkening

The picture of the Sun today shows again a Sun without any sunspots. So far this year, 104 spotless days are registrated; in 2017, it took a full year for those 104 spotless days. This means we are heading towards a solar minimum.

The picture also shows the Sun is more bright at the center and darker towards the edges. This phenomena is called Limb Darkening - which I will explain later (when I have time :)

Sun with SolarMax III and ASI224MC

The Sun today around UT08h45 observed with SolarMax III (f/5.7 70/400 DS BF15) and ASI224MC for 60s. This time true color stacking providing a red color instead of BGGR blue color (see my blog here). 

The Sun with SolarMax3 and ASI224MC

The Sun this morning; observation with SolarMax 3 (f/5.7 70/400; BS en BF15) and ASI224MC. Capturesoftware SharpCap for 60s and stacking using AutoStakkert in BGGR. This results in a (false) blue color, but the provides a nive and higher contrast. Located centrally on the Sun's disk you can see a white bright active region, but without sunspots. Also different prominences can be see at the limb of the Sun.

Nightscape Milky Way and Mars

Some nightscapes from my backyard. One with our own galaxy or Milky Way and one with part of the Milky Way and Mars.

Mars TAL200K ASI224MC - Record of 58.000 frames

Last night I was able to take some more pictures of Mars. Mars is currently very bright and getting bigger every night. Details are now visile on Mars's disk. A total of 58.000 frames were made due to the fact I was able to lower the capture area and the fact the scope was well positioned.

Pictures made with capture software SharpCap and stacking with AutoStakkert. Final editing by CS4.

Mars this morning

Mars is currently clearly the brightest object in the sky. This morning the sky was cloudfree (except the north-west part) and pictures were taken using TAL200K ASI224MC without barlow. Capture area was set to 400x480 resulting in more then 200fps. Total frames taken was 57.000 which are stacked with AutoStakkert. Limited editing using CS4.

Dark and light areas are good visible; also when observing visualy.

Fascinating Jupiter and the Great Red Spot

The Great Red Spot (GRS) captured on this picture is located centrally on Jupiter's Disk and measures the size of the Earth.
This is one of my most fascinating pictures of Jupiter with the GRS. I took the picture during twilight and reduced the capture area to 640x400 boosting up the maximum frames per second.

Mars with TAL200K ASI224MC

This morning we have a clear sky and temperatures around 14°C. The planet Mars is visible 15° above the Southern horizon. Current magnitude -2.4 and diameter 22'30"; by the end of this month Mars will have a magnitude of -2.8 and a diameter of 24'30".

Both visual as photographic, light and dark areas can be seen on Mars. I was not able to see the white poles. All pictures are taken with TAL200K, ASI224MC and barlowx2. Capture software SharpCap was used with an exposure time of 180s providing max. frames of 19.000. Stacking with AutoStakkert and final editing using CS4. 

 

Frame rate was increased by reducing the capture area from 1300x900 to 480x400. 

Jupiter and GRS

The GRS or Great Red Spot as seen central on Jupiter's Disk. Jupiter rotates on its axes about less then 10h; this is clearly seen below, when watching the GRS. Time difference between both pictures is 14minutes or 9°.

Jupiter and GRS

At this moment the Great Red Spot (GRS) is visible, central on Jupiter's disk. Picture taken with capture software SharpCap and stacking using AutoStakkert. Final editing with CS4.

Mars, Jupiter and Saturn with TAL200K ASI224MC

All three planets were observed during the night of June 29-30.