Archive for the ASTRO Category

ISS solar transit – April 25, 2018

Posted in ASTRO on April 25, 2018 by maxpho

And yet another solar transit by the ISS. This time I was not sure that I could get to the location predicted via CalSky, so I did not have great expectations…

But, luckily, after going a bit over the speed limit ;), I found myself in a nice field of…green stuff. Nevertheless, this type of astrophotography is never easy, so a few clouds had to cover the Sun just 5 minutes before the event…

Again, luckily, the clouds dispersed 1 minute (!!) before the transit, so that I could focus and wait for the black silhouette of the ISS to pass. Seeing was terrible, but the pass was favorable with many details of the ISS structure well resolved.

I might have been speeding on the roads, but it is nothing compared to the speed of the ISS in orbit…the transit lasted about 0.5 seconds…

The setup: homemade 150mm F/5 refractor (iStar lens), Herschel wedge, 2.7x APM coma correcting barlow, Baader green filter, ASI 174MM.


The cloud that formed 5 minutes before the event:


A short animation (resized) showing the event at a very low frame rate:

ISS APRIL 25.gif

A single frame (the best out of about 36), showing the ISS near sunspot 2706:


And the sequence:

ISStransit April 25a.jpg




High Resolution Lunar images – April 23, 2018

Posted in ASTRO on April 24, 2018 by maxpho

A lunar session under almost perfect seeing conditions. Well, not all the time, but for about 30 minutes the seeing was very close to perfect. It is definitely one of the most memorable imaging session in recent years for me.

Equipment: 355mm F/4.5 homemade Newton, 2.7x coma corrected barlow, and 2.5x Baader barlow (for green light only). ASI 174MM with either a Red filter or a Green one! Yes, I could finally use a Green filter for lunar imaging, which is extremely rare.

First, the higher magnification Green filtered images.

Atlas and Hercules:








The prominent trio of craters Arzachel, Alphonsus and Ptlemaeus in good seeing (7/10) at the beginning of the session.  Another better version, in 8-9/10 seeing, is being processed.


Crater Moretus and the southern mountains.


Craters Petavius and Humboldt in high Sun illumination. One of the shots I was aiming for some years now…


The Needle Galaxy – April 21, 2018

Posted in ASTRO on April 23, 2018 by maxpho

This is the result from a wonderful session deep inside the woods around Targoviste, Romania. A few roars from different animals, a few insects around the laptop, and the flight of a few bats were all contributing to the atmosphere…Nature at its best.

The following shot (please zoom in) shows the interesting edge-on galaxy that it is best known as “the Needle galaxy”, located in Coma Berenices. More interesting is the immense number of far-away galaxies present in the field: most of the small diffuse points of light in the image are actually galaxies not stars.

This was also the first true test of my homemade cooling for the ASI 1600MM camera. From the normal 14-15 degrees Celsius (wit 12 degrees ambient air temperature) the sensor temperature was lowered at about 6 degrees; it allowed for so much less noise to be present in the subs. I may get eventually a more efficient cooling system, but for now it is good enough.

Needle galaxy.jpg

The Moon – April 22, 2018

Posted in ASTRO on April 22, 2018 by maxpho

A very short session with the Moon. Despite the poor seeing, the experience of imaging from deep in the forest is something to remember. This image was acquired with the 115 mm refractor and ASI 174MM camera with a green filter in 4/10 seeing conditions.


H-alpha Sun – April 21, 2018

Posted in ASTRO on April 21, 2018 by maxpho

A lovely solar session today, in the woods around Targoviste. Good seeing but some technical difficulties…

Nevertheless, a nice active region (AR 2706) is giving us a very nice display both in white light and H-alpha light.

Equipment: TS 115mm APO F/7, Quark Chromosphere, ASI 174MM for H-alpha images. A. Herschel wedge was used for the white light shot. Seeing 6/10.

sunspots wl.jpg


h alpha a.jpg

inverted h alpha.jpg


Moon – April 20, 2018

Posted in ASTRO on April 20, 2018 by maxpho

One Moon shot. Note the bright peaks far away from the terminator line, towards the South Pole.



H-alpha solar images – April 15, 2018

Posted in ASTRO on April 15, 2018 by maxpho

Some solar images with the homemade 150mm solar refractor…

Poor to fair seeing, so I could not test the true power of this scope on the Sun. Despite that, a nice solar prominence was present on the limb. Also, a new active region developed close to an older one (imaged yesterday); it can be seen with a small flare in the images below.

Technical details: 150mm F/5 homemade acromat (iStar lens), 50mm ERF filter, Quark Chromosphere, ASI 174MM. Seeing 4-6/10.



Active regions.jpg