Archive for the ‘Celestron C8’ Category

Crescent of Venus

Friday, July 13th, 2007

Friday 13th, after 8 weeks of rain finally a nice sunset with Venus (and Saturn, but I did not see it). Seconds before it hid behind a building.
July 13th, 18h50 UT,



First Jupiter of the season

Monday, June 4th, 2007

Very low in the sky at 13 degrees, and it will not get much higher this year. Not even a hint of the Great Red Spot is observed . The moon visible at the right is Io (magnitude 5.5). Image taken around 23h50.




Saturn again

Sunday, April 8th, 2007

From a 4000 frame movie with good seeing (best so far this year).


Sharpening was done using Wiener deconvolution in Matlab with a PSF simulated in Aberrator:



Friday, April 6th, 2007

Very bright, but quite featureless (unless imaged in UV).

This is the red channel from a stack of Venus images, which is the sharpest since red light suffers less from bad seeing.

14 arc seconds diameter
magnitude -4
phase: 77%


Perfect seeing, perfect telescope

Tuesday, April 3rd, 2007

In an ideal world, a 512 pixel wide Saturn image would look like this:


But if an 8 inch telescope (like C8) would be used in perfect seeing, the resolution would be limited to (simulated with Aberrator):

For the 90 mm ETX90 it would look like:


Saturn and “good” seeing

Sunday, March 11th, 2007

A high pressure zone, little jetstream… seems like the perfect night. After thorough collimation and focussing the result still was not 100%: March 11th, 2300h.

Using  my hoem grown registration/stacking in MatLab:


And another attempt at processing in Registax 4:


And another in Registax using all 4 movies made:


Saturn and its moons

Sunday, February 4th, 2007


As seeing was not so good, I used the opportunity to image the moons of Saturn using the webcam at maximum sensitivity, while later adding Saturn itself, acquired at lower sensitivity. The moons and their respective magnitude are shown. Mimas (mag 12.8) was overshadowed by the blowout of Saturn and Hyperion was simply invisible (mag 14.1!). The sizes of the moons in the image nicely match their increasing magnitude. The Celestron C8 was used without Barlow in combination with the Philips Toucam.

The same view in HNSky:


Saturn close to the moon

Saturday, February 3rd, 2007


As saturn was close to the moon, my telescope fogging up and seeing was poor, this is the best I could do.