23 December 2013

Astronomy club's 6 months Pinhole Solargraph revealed. Great experience!

6 months pinhole camera revealing Sun's arcs in the sky.
Credit: KTY Toutatis / S. Lamoureux
Astronomy Club Toutatis.
Kustavi, Finland

As the winter solstice arrived, it was time to open the long awaited Pin hole camera hanging from my balcony.

Back in June 2013 we made a Solargraph using an empty film roll can with a pinhole and photographic paper inside. The exposure time was 6 months! 

You see on the picture bright lines of "light". These bright lines are the Sun in it's path in the sky.
The highest arcs were traced by the summer sun of June 2013. The lowest arc was made by the sun on December 20th 2013, on the winter solstice. Occasional gaps in the bright lines are caused by clouds that blocks the Sun.

Pinhole Camera battered by weather.
This experience was pretty cool! In the Summer I watched as the camera was hanging from my balcony and wonder what will the photo look like after 6 months. After a while I forgot about it and from time to time, the camera popped into my head and I get all excited to open it in December. Now that December has arrived, I can tell you that 6 months have passed really quickly. 

Next generation of Pinhole camera for 6 months exposure.
For the year 2014, I have made 2 new Solargraphs (Pinhole camera).
One camera is at our Astronomy club's balcony and the other one is on my home balcony 60 km apart looking both Southern direction. 
This time I didn't use a camera roll can, but instead a soda can with a bigger photographic paper inside. 
Here are some links for doing your own Solargraph.

02 December 2013

Comet ISON has left the celestial building!

Image from satellite SOHO
02.12.2013 Kustavi, Finland

Comet C/2012 S1 ISON hit it's perihelion on Nov. 28th 2013 and had a rough encounter with our Sun. Everybody was looking forward to see Comet ISON raising from the dead and giving us a spectacular show, but no! Comet ISON broke apart and spewed a big cloud of debris.

Against 8:30 p.m. yesterday evening, the tail of ISON emerged from behind sun in the field of view of the LASCO instrument. At this point in time, however, it was unclear whether the tip of the tail concealed a nucleus or not. Pictures taken a few hours after Perihelion now allow further conclusions to be drawn.
"The dust tail of the comet is now divided into two parts," explains Hermann Böhnhardt from the Max Planck Institute for Solar System Research. According to Böhnhardt, the part of the tail that is pointing towards the sun consists of dust particles, which were released significantly before the comet's Perihelion passage – i.e. prior to reaching the closest point to the sun.

The other part, however, appears to contain more recent material: It was released when ISON passed the sun and suggests that at least part of the nucleus still existed and was active at that time.

The Max Planck researchers base their assessment on computer simulations in which they model the shape of the dust tail. "If we assume in our calculations that the comet has emitted dust at Perihelion, we can reproduce the current images quite well," says Böhnhardt.

The LASCO images from Saturday showed the ISON stopped producing dust two hours after Perihelion. Whether the comet nucleus was still intact at Perihelion or continued its flight as a small fragment or as collection of chunks is not yet clear.

The instrument Sumer on board of the satellite SOHO, which was developed and built under the auspices of the Max Planck Institute in Lindau observed ISON on Thursday night in the hour when it directly approached the sun. The instrument divides the light that is sent into space by the celestial body into its individual components. From this, researchers can draw conclusions about the elements and molecules in the comet's dust cloud.

"Our measurements show a clear signal of the comet during its flight past the sun," says Max Planck scientist Werner Curdt. Exact results of the measurement, however, are not yet available.