Apr 302016

The last two nights were the first planetary tests of my ‘new’ Point Grey solar system camera. Up till now I have only used it to image the Sun through the H-Alpha telescope. Thursday night was a shakedown run to make sure all the correct camera drivers and software were installed and to see if I could find a planet sized target with the camera’s small field of view. I did not have any problems and the end-to-end ‘process’ worked fine but the images produced by the camera were very small. It also became very obvious that I really missed focus.

p_Jup_215141_g3_ap14 p_Sat_015834_g3_ap10

So last night I added a x2 Barlow to the mix. It made finding the planet a little more difficult but the image size is now large enough to work with. This image of Jupiter is the best 5,000 frames of a 10,000 frame video capture through the x2 Barlow. The dark spot visible near the right edge of the planet is the shadow cast by the Galilean moon Io. The moon has not left the disk of the planet and as such is in the image but I cannot reliably pick it out. The planet is displayed in the traditional orientation with south at the top. Unfortunately, clouds moved in before Saturn rose above the tree line so I was not able to include it in last night’s test.


This is also the first time I have used Firecapture to record the video stream. Firecapture is free software that supports many machine vision cameras and is a very popular package for solar system imagers.

I consider last night’s test a success and will, for now, use that configuration as my standard for planetary imaging. The next step is to integrate a filter wheel and RGB filters to add color to the images.

 Posted by at 16:05
Mar 112016

First, the PTO is finally back online. Now the painful details:

The original diagnosis of the new mount having a personality problem was incorrect. The control box and hand paddle checked out fine and were returned unharmed. As expected, the mount still suffered from pointing problems; both in positioning and parking. After an additional session of phone diagnostics with George from Astro-Physics (thanks George) the RA gearbox was dismounted and sent back to the factory for inspection and repair. George also requested the GTOCP3 control box accompany the gearbox (its second trip back home). The return paperwork listed new spur and cluster gears as the fix. While they had the control panel the troops at AP ran modeling software on the repaired gearbox and loaded a new PEC model into it.

With the repaired and reprogrammed parts reinstalled, the mount was ready for testing. We finally got some clear skies to align and test it and the results are amazing. With the old mount I was able to reliably take an unguided 30 second exposure without any visible distortion in a star’s image. A guided 300 second image would routinely pass a 0.2 roundness test. Now I can take an unguided 300 second image where the stars routinely pass a 0.05 roundness test.

The old mount’s less than optimal performance is not entirely its fault. First, I had loaded the mount right to its advertised limit (and over time probably a little more). Also, the polar alignment was off slightly in elevation. I found making fine adjustments to the elevation axis very difficult. I’m pretty sure this was mostly due to the design of the adjusting mechanism dealing with the weight the mount was carrying.

Of course, the primary reason for the observatory upgrade was to increase the load capability of the mount for the new (refurbished) telescope.

Installing the new scope will be the final step in this PTO upgrade. Watch this space.

<<< Progress report (Part 2) Progress report (Part 4) >>>
 Posted by at 11:22
Mar 032016

Comet 67P/Churyumov-Gerasimenko holds the distinction of being the first comet to be orbited by a spacecraft as well as the first to have a probe soft land on its surface. After a 10 year trip the Rosetta spacecraft entered orbit and on November 12, 2014 dropped its lander (Philae) on to the nucleus. The primary purpose of the mission was to characterize the comet and its behaviour during its perihelion passage on 13 August 2015. The comet, with its attendants, is now heading back out into deep space and will return to visit the inner solar system in 2023.


67P/Chuyumov-Gerasimenko [C:15x120s]

This image is a stack of fifteen 120 second exposures with the images registered to the comet. The image is very noisy as the Moon was very close and there was some faint wispy clouds overhead.
Chart generated with Cartes du Ciel

Chart generated with Cartes du Ciel

FYI, the comet symbol on the chart is not an indicator of the tail orientation. Also, notice the obvious difference between the comet’s predicted position in the chart versus the actual position in the image stack.

 Posted by at 18:15
Feb 192016

A quick look at the SDO web site on the morning of the 30th of January showed a very large prominence visible in the Hydrogen-Alpha image. I quickly set up my portable mount and solar telescope and was able to capture this image. I had to overexpose the disk of the Sun quite a bit in order to view the prominence. There was a fairly constant light layer of clouds in the sky above and that led to the soft focus.


 Posted by at 00:11
Jan 272016

Since I am now waiting for the reprogrammed mount control panel to return I have some time to catch up with some archived imagery.

Once thought to be a supernova remnant, this nebula is now known to be an old planetary nebula. It was discovered by renowned astronomer George Abell in 1955. This is one of the first objects in the Sharpless catalog that I have imaged.

Using Palomar Sky Survey plates as source material, US Naval Observatory astronomer Stewart Sharpless published two catalogs of H II regions. The catalogs also contain some planetary nebulae and supernova remnants. This nebula is one of those and the 274th item in his second catalog.

Medusa Nebula (SH 2-274) [C:60x30s]

Medusa Nebula (SH 2-274) [C:60x30s]

Chart generated with Cartes du Ciel

Chart generated with Cartes du Ciel

The nebula is located in the constellation Gemini on the border with Canis Minor. It is estimated to be about 1500 light years distant. Deeper exposures than this show the nebula to have a braided appearance hence the Greek mythology Medusa name reference. The nebula is also cataloged as PK 205+14.1 in the catalogue of galactic planetary nebulae published by Czech astronomers Luboš Perek and Luboš Kohoutek.

 Posted by at 12:27