Astrophotography

Your attention please!, some of the photos in this web page were used to foll some of the members of the Astronomical Society of Granada. If you want to read the fake story about the images you can do it in Más con Menos.

Some months ago we bought some new astronomical gadgets, but due to bad weather ad a fire in our observation place make it impossible to try it until last week. Among other equipment, we now have a monochrome Lunático QHY-9 CCD camera. It main characteristics are the following:

• CCD Sensor: KAF8300 (black & white)
• Total Pixels: 3448x2574 (8.9mega pixel)
• Effective Pixels: 3358x2536 (8.6mega pixel)
• Pixel Size: 5.4μmx5.4μm
  

After a winter full of clouds and even more clouds, last Saturday night was a clear enough one to do some astronomy. Mars was waiting us there in their oposition (although not one of its bests) and so we could miss the chance to take some photos of it.

In this occasion we have slightly change our usual observation site in La Azotea (in the middle of Granada city) to a quite near village, Armilla.

After some months without taking out the 25 Obsession Telescope, we go up to the observation place called “Dornajo” in order to take some shot of Jupiter trough the webcam. The operation began at 5 in the afternoon picking up the whole necessary material distributed in several places. 

After several hours, we had the 25 inches telescope mounted above the equatorial platform and polar aligned. It began what seemed a fantastic, windless and clear night. Some time later Javier Algarra arrived and also mounted their impressive Taka. While we spoke about the new astronomical gadget a bank of fog didn't allow us to see anything in the sky. The humidity also at this time overtook the saturation level soaking the whole material. After a half hour, the sky cleared up and we could begin with the planet Jupiter. 

The seeing was not bad but the wind blew in gusts that made very difficult to maintain the planet inside the small ccd of the webcam. Some hours later the moon rose over the horizon and we waited to a better position close to the zenith to tray a mosaic of its surface. In order to get that we used the QHY5 CCD, but once again, the wind hinders us vastly and prevents us taking some quality videos and it didn't give us time to cover the whole surface. In spite of it, a good frame selection, the use of the appropriate software (including our new ManualFrameAlignment) and many processing hours, allowed us to obtain these results:

Remark: Even though we could have incremented the contrast in the Jupiter image, we have tried to obtain a result as close as what we really saw that night through the telescope's eyepiece.

Some additional of Jupiter and Moon takes from last Sunday. Seeing was much better than in previous attempts and we tried to use two barlow lenses (3x and 2x) together. Click them to watch them at full resolution:

Last Friday, after the S.A.G. meeting we tried to photograph Jupiter from La Azotea. Sky conditions were terrible. The results can be improved, but it is a good start. In the first photograph we didn't obtain good enough focus. In the second one focus is better, but some artifacts appear due to some spots and dirt on the CCD. The third one is a new attempt to reprocess the image using the last version of Registax and using supersampling. We think we have improved it a lot removing almost all the previous noise.

We have added a video to show a small clip of the original raw video that we used. It can be noticed that seeing was quite bad. The original video had around 4700 frames of which 2700 had to be discarded due to bad quality (and a cloud that passed by). In the video you can see some of the GOOD frames that we used. Note that Youtube has added some compression artifacts (squares) that are not visible in the original video.

The night of May 18 to May 19 was a fantastic occasion to go up to La Azotea and continue with our astrophotography learning sessions.

In fact, we were almost using for the first time our new "observatory wardrobe" where we are storing the heaviest items of our equipment (counterweights and tripods) and from which we directly have a power point and an Internet cable, which is quite useful to watch weather predictions from  Meteosat, to watch a film during the photo series or even to inform in real time about what we are doing there.

The night of Saturday March 14th, was again very good for astronomy. After the set up of all the devices, and done a precise alignment to the Polar star, the main goal for this night was the Orion nebula through the refrigerated QHY6 CCD, besides other type of objects as galaxies. The humidity oscillated in the whole night around 50 - 60% and the temperature was about 10 grades which was very bearable.

On Friday, after a spectacular SAG (Sociedad Astronómica Granadina) meeting, we continued to cut our suitcases foam to store the last equipment that we have acquired. The technique to cut the foam is quite easy to implement and the results are also quite good. It is done by using a hot wire that cuts the foam following a paper pattern. In the photograph you can see an example of the cutting of a 2" prism shape. In the future we will publish a tutorial on how to cut foam.

The night of February 24, 2009 the comet Lulin was in its nearest distance from Earth and so it was visible to the naked eye in dark sky places.

We decided to make a short observation session and to try to take some photos from it. In fact, Javier Algarra (member of the S.A.G.) had called us in the afternoon confirming that he would be there taking some photos (he has been taking photos of the comet for the last days). For us was quite complicated to go to the observation place because we had previous engagements and we could not leave until 10:30pm.

After waiting for may days for the good weather to come back to make some observation sessions, and what it is more important, begin taking astrophotographies, the evening  of February 14 looked quite promising. We thought that it would be a nice day to make our observing session in the Carretera de la Cabra, but last minute clouds made us change our opinion, so we decided to go to the Dornajo terrace in Sierra Nevada.

Once the van was fully loaded, we took the Sierra Nevada road and in the Centro de Interpretación exit we took the secondary road that goes near the terrace. Big error. The forbidden traffic signal, that we interpreted as "it is not recommended to use this road", was really more important than we initially thought. Half a kilometer up the road, the black asphalt turned into a quite good ice skating rink. The van could not go over the ice for more than five meters when it began to turn, getting crossed in the middle of the road and slipping back. At that point Antonio turned his head to say something to Zerjillo (the co-pilot) when he notices that he is already outside the van watching the show.