Jan 312018
 

The target of this image is NGC 2149, a small reflection nebula in the constellation Monoceros (the Unicorn). It is quite near the constellation Orion and often gets overlooked due to the more flamboyant objects in “The Hunter”. I routinely exclude images taken of deep sky objects when a satellite intrudes into the photo. The brightness of the intruder skews the desired object’s post processing. I must admit however, last night I intentionally chose NGC 2149 because of the impending satellite pass. The guilty party this time was the Hubble Space Telescope.
 

I decided to attempt the exposure knowing full well the Moon’s brightness would cause a strong gradient in the exposures. After all, the Moon was only a few hours from entering the Earth’s shadow and the resultant total lunar eclipse. Hubble would cross my FOV in just over one second. It takes 10 seconds to download an image from my camera, so in order to not miss the pass I set the exposure to 300 seconds and started it a couple of minutes before the expected arrival. I then joined family members in the front yard to watch the flyby. Hubble silently glided west to east and near the point where it disappeared, it did its best imitation of an Iridium flare. The scope’s solar arrays were at just the right angle to reflect the Sun’s light right back at us. It then faded as its orbit took it into the Earth’s shadow.

Luckily, the satellite’s orbital elements used to predict its path were right on and the 300 second exposure showed the very bright telescope streaking through the image. I then took additional images of the nebula to increase its brightness a little. The result is a stack of one 300 second image and 25 sixty second images.

 Posted by at 15:17
Jan 072018
 

Comet Heinze continues to climb above the plane of the solar system and the Earth is now pulling away from the comet. It is still outside Earth’s orbit as it heads toward perihelion on the 21st of February. It now appears in Cassiopeia on its tour of our constellations.
 

 

These images were taken last night (the 6th). The comet’s tail is becoming more apparent. There were some high thin clouds that were passing and are evident in the animation. I added a second pass thorough the images at a slower rate to make it easier to pick out the two satellites that photobombed the comet. One is in one frame and passes from bottom left to right center (or vice versa). The second is a much slower satellite. It takes two frames (10 min) to pass from bottom center to top right.

The PTO’s tree obstructed view of the sky.
Chart generated by TheSkyX.

 Posted by at 19:35
Jan 072018
 

These images were taken the evening of the 4th of January. So, between the images taken on the 3rd and 4th the Earth – Comet distance closed to only 20.5 million miles.
 

 

The comet has now passed into the northern constellation Camelopardalis (the giraffe) and the brightest star that becomes visible in the animation is Alpha Camelopardalis. This star is naked eye visible at a magnitude of 4.26. Unfortunately, the stars brightness combined with the 300 second exposure caused problems with the processing. The anti-blooming steps left strong visible artifacts in a couple of the images, but luckily they did not impact the image of the comet.

The PTO’s tree obstructed view of the sky.
Chart generated by TheSkyX.

 Posted by at 16:56
Jan 052018
 

Comet Heinze continues to approach the Sun. As of the 3rd of January it was still in the constellation Lynx and still outside Earth’s orbit. The comet will not cross Earth’s orbit until the 16th of January but by then the Earth will be well ahead of and well below the comet.
 

 

All objects that orbit the Sun obey Kepler’s laws of motion. This comet is no exception. The 2nd law states “a line segment joining an orbiting object and the Sun sweeps out equal areas during equal intervals of time”. Simply stated, the closer the object is to the Sun, the faster it moves. You can see this in action by comparing the previous animations. Each of the individual exposures are 300 seconds long. By comparing the length of the streaks made by the stars you can easily see the comet moving farther in 300 seconds the closer it gets to the Sun.

The PTO’s tree obstructed view of the sky.
Chart generated by TheSkyX.

 
Also visible in the first exposure is the bright streak of a satellite. There are so many satellites in orbit around the Earth it is not unusual for a series of exposures to capture one. For long exposure images I have to leave those sub-exposures out of the processing. The bright streak will skew the final image.

 Posted by at 12:10
Dec 302017
 

The PTO continues to follow comet C/2017 T1 (Heinze) as it gets closer to the Sun and, for now, the Earth. Closest approach to the Earth is still forecast for the 4th of January, so it has a few more days to go yet. This animation is only eight 300 second exposures. Earlier maintenance work I was doing in the observatory left the telescope out of focus and I did not notice until the third exposure of the 11 I had scheduled.
 

 

The comet has now crossed into the northern constellation Lynx. It is still between the orbits of Earth and Mars and is now slightly above the plane of the Solar System.

The PTO’s tree obstructed view of the sky.
Chart generated by TheSkyX.

 

 Posted by at 12:33