Misty Weather

Even the fact I can see some stars, the sky is covered with mist. The street lights reflect the light due to the small droplets so badly that it is not possible to make any observations.

The sun today - PST comparison with SDO data

Clear skies so time to observe the sun with PST 40. One big prominence at 11h and smaller ones at 4h and 9h. I made a comparison with data from SDO and the result is shown below. I must say that the comparison is very good. My picture was made afocal using a 8-24mm zoomlens and edited using CS4.

No sunspots but bright sundogs

No sunspots today but due to low and high clouds it was ideal for observing some bright sundogs.

Astronomical Highlights 2016

My Astronomical Highlights of 2016 with the Transit of Mercurius, my first Deepsky Pictures, observing Noctilucent Clouds and the Making of the Moonphases.

The planets with Jupiter and the Transit of Mercurius

My first deepsky pictures M42 en M57

The sun this year

Noctilucent clouds in July  :

Moonphases in December :

Happy Birthday : 4 Year blogging

Celebrating 4 year of blogging ... started on December 23, 2012

Solargraph Failed due to overexposure.

As mentioned earlier, one pinhole camera disappeared a month ago and yesterday I found out that after 6 months exposure my other one did not show much details.
Bad luck but what can we learn from this?
My conclusion of the latter is that the paper was overexposed. This probably because the can (this time a used a piece of a "sewer pipe") wasn't light prove, so the sun could penetrate through the can and did expose the paper.  Instead of exposing the paper via the pinhole.

Why a Red Sky in the Morning?

This morning again a beautiful red sky. But why a red sky? This because of a phenomenon called Rayleigh Scattering. When light travels through a medium with particles smaller (eg. moisture) than the wavelength of light then light will be scattered. The intensity of the scattered light is also dependant of the wavelength (～𝛌-4). For that with blue light having a 2x shorter wavelenght then red light, this means blue light is 16x more scattered then red light. That's the reason why we have a blue sky and not a red... blue is more scattered with having more chance that blue light will hit our eyes.
So now, why a red morning. Ah... this is because in the morning/evening, when the sun is low at the sky, light travels much longer then during the day through the atmosphere. The distacnce can be as even 12x longer then during daytime. So the chance that blue light is fully scattered is very likely and only the red light is available to reach our eyes (so no blue light is left :) )