Archive for September, 2018

Moon-rise and Moon-size – September 26, 2018

Posted in ASTRO on September 27, 2018 by maxpho

A lovely Moonrise today, with an apparently HUGE orange Moon lifting off the ground. Nice to see in real-time the effects of Earth’s atmosphere on the shape of the Moon.

Equipment: Newton 200mm, F/5, ASI 1600MM with no filter in Binning 2×2.


And since the Moon looks so huge to most people when it is close to the horizon (the Moon illusion), I’ve decided to wait a couple more hours and acquire another sequence with exactly the same equipment, in order to compare the size of our satellite in the two circumstances. The results speak for themselves: not only the Moon is not larger when it is close to the horizon, but it is actually SMALLER! 🙂




Harvest Moon – September 23, 2018

Posted in ASTRO on September 24, 2018 by maxpho

Since it will be raining the night when the Full Moon occurs, I’ve decided to get a fast image of the Harvest Moon one day before, from an agricultural field (quite appropriate for this Moon). The low altitude of the Moon and some smoke from a nearby fire made the view quite interesting…

Equipment: 200mm Newton, ASI 174MM, Red filter. Mosaic of 15 frames, resized to about 70% from original.


Saturn near the Lagoon – September 20, 2018

Posted in ASTRO on September 21, 2018 by maxpho

I did eventually manage to image the planet Saturn next to the two well known nebulae, TH Lagoon and Trifid (Messier 8 and Messier 20).

Equipment: Jupiter 37A 135 F/3.5 (@F/4) lens, Bader 7nm H-alpha filter, ASI 1600MM, Bin 2×2, 15x120sec, Gain 150, Gamma 60, Sensor temp (without cooling): +18 Celsius. Guiding via PHD2 and a 50mm lens with ASI174MM.


H-alpha Sun – September 20, 2018

Posted in ASTRO on September 21, 2018 by maxpho

I’ve spent almost one hour today imaging the Sun with the 150mm achromat and Quark H-alpha filter. Some decent seeing at times, and a few nice proms on the Sun’s limb. Not much activity in the chromosphere, with no active regions.



A one-hour animation showing the evolution of the largest prominence visible on September 20. Nice dance from this prom, with some plasma strings traveling in the “canopy” of the prom, and some “thunder” like appearance of the “legs” of the proms.

Only 14 frames were obtained, and the transition in some moments has gaps, but the general dance is well seen.

sept 20 proms.gif

Testing an old lens for Astrophotography – September 19, 2018

Posted in ASTRO on September 20, 2018 by maxpho

A long time ago (20 years ago actually) I’ve received from my father a camera system (that he was using as an amateur photographer) that included the lovely Zenit-E SLR and the Jupiter 37A lens. I’ve kept this lens in a forgotten box for the last 10 years or so, occasionally finding and playing with it for a few minutes. After that it was again in its box…

But today, I’ve found it again and…

I was convinced that a lens with such good photo reviews should also be good for astrophotography. My specimen was build in 1984, as the serial on the lens ring indicates. So it is about 34 years old, almost as old as I am…pretty cool 🙂

Now, for the test: the main reason for choosing this lens for this session was to have a  wider field of view on some deep-sky objects in H-alpha light. The nominal 135mm focal length is perfect for the job, when combined with the small pixels of the ASI 1600MM camera. But to focus the system, I’ve first pointed at the Moon. The result is spectacular I might say, with lots of identifiable craters detectable in the image. Very sharp image, and this with the lens wide-open at F/3.5! Indeed, it was done through the H-alpha filter, so not much optical aberrations would have been detected, but this also means that the lens is very well corrected in the red part of the spectrum. And this is from a lens of just 38.5 mm in diameter!


With such good resolution, the next target was chosen: the North America-Pelican nebulae. Only five frames (each a 10 minutes exposure) for this one for now, but it will definitely be my subject for the next clear nights:


And another short test, just to see “what’s out there”, in an area that includes the Omega and Eagle nebulae. Only 4x120sec shots and 1 dark were acquired. The Moon was also pretty close by, and the area was already rather close to the horizon; still a lot of fainter hydrogen signatures can be seen in the background:


And the last shot, Saturn next to the Lagoon and Trifid nebulae, setting behind a tree. Only one shot of just 60 seconds. This gathering is my prime target for the next session…


The conclusion for now is that this lovely small lens is pretty good for astrophotography, at least in H-alpha light. It does however show some coma towards the margins with the ASI 1600MM camera, but this is visible with the lens wide open. Perhaps at a different F-stop it will be better. The next session will show just how good the lens can be…

And a shot of the setup: the Jupiter 37A and ASI1600MM (in the foreground), and the guiding scope (a 50mm finder with ASI 174MM camera):


Just after the First Quarter – September 17, 2018

Posted in ASTRO on September 18, 2018 by maxpho

A short night time test of my new/old achromat refractor. It looks like this scope is OK in the green part of the spectrum (as any good achromat should be).

Following is a shot of the Moon, using the ASI1600MM with a green filter, placed directly in the focal plane of the scope. The Moon was rather low, at 20 degrees above the horizon, and the seeing was around 4-5/10.


H-alpha Sun – September 15, 2018

Posted in ASTRO on September 16, 2018 by maxpho

A very nice imaging session with the Sun today, using the newly acquired 150mm achromat refractor. The seeing was mostly good, and some very nice prominences were observable on the limb. Also a small active region was present.

Yesterday’s proms have now departed, but still a hint of their upper regions is seen in the image below:


And a two-frame evolution image:


The discrete active region:


One of the newly emerged proms, with a half-an-hour evolution:

Another prom.jpg

And another prom, looking like a dancing flame:


A 45-minute evolution of today’s “dancing-flame” prom:


And a rather faint prom: