Saturn and its Moons

 

A compilation widefield images of the gas giant planet Saturn and five of its moons on the 8th of September 2012. Images taken with 127mm Meade Apo Refractor, x3 Barlow lens and a QHY5l-11 colour video camera. Credit: Pip Stakkert.

" Imaging Saturn remains difficult as the planet is very low on our southern horizon in Lowestoft. The location of the moons: Titan, Dione and Rhea was easy to achieve but Tethys and Enceladus, being close and therefore lost in the glare from Saturn, required the position of the moons to be estimated using planetarium software. Saturn is probably one of the most beautiful astronomical objects to be viewed through the eyepiece of a telescope." - Karl Seguine Community Outreach Coordinator at the Jodrell Plank Observatory.

The Great Red Spot 2021

 

The Great Red Spot visible on Jupiter's Disc. 127mm Meade Apo Refractor, x3 Barlow and QHY5L-11 colour camera. 3 minute video clip stacked. Credit Pip Stakkert.

JunoCam on the JUNO Spacecraft: Image processing from RAW download by Pip Stakkert .   Credit for data NASA, JPL, SwRI. 
Mission Phase: PERIJOVE SwRI/35 2021-07-21 08:44 UT

" Our images of Jupiter captured on the 8th of September 2021 show the Great Red Spot, an enormous anticyclone, looking paler and smaller than in previous years. When we look at Jupiter through a telescope we see the turbulent weather systems and clouds reflecting sunlight which takes approximately 77 minutes for the round trip. The cloud systems are in constant movement driven by internal heat and the energy imparted by the planet's high rate of spin. Amongst this metrological chaos the red spot has remained a constant feature. In the last few years the GRS has grown smaller and paler. At the same time, large white ovals or spots have appeared in and around the South Equatorial Belt. Interaction with the white ovals appears to have resulted in the GRS becoming paler and smaller." - Kurt Thrust current Director of the Jodrell Plank Observatory.

Gas Giants in September 2021

 

Jupiter 08-09-2021, Meade 127mm Apo refractor-QHY5L-11c camera - 3minute avi clip stacked. Credit: Pip Stakkert.

Saturn 08-09-2021, Meade 127mm Apo refractor-QHY5L-11c camera - 9 minute avi clip stacked. Credit: Pip Stakkert.

" The weather forecast for the night of the 8th of September was not good but the weather was predicted to deteriorate in the nights following. We therefore decided to give imaging the gas giant planets, Jupiter and Saturn, a go anyway. 

The planets remain low on our southern horizon and there was also a hint of high level cloud both of which made obtaining sharp images problematic. Saturn being the lower of the two planets was wobbling about all over the place and was difficult to focus. The day had been quite hot in Lowestoft and residual heat radiating from adjoining house roofs exacerbated the atmospheric problems. The difference in image quality between Jupiter and Saturn is clear. Jupiter being much closer, bigger and at a greater declination all go to making for a sharper more detailed image.  Over the next few years the planets will get higher in the sky in the Northern Hemisphere.

If you look closely at the image of Jupiter you can just make out the Great Red Spot towards the bottom of the sphere at about '5 o clock' on the planet's limb. You can also see that Jupiter is not a perfect sphere, having a greater diameter measured at the equator than through the poles. Jupiter is an 'oblate spheroid'. This is because Jupiter is made from primarily gas and is rotating at considerable speed. The Jupiter day is only 10 hours long!  Centrifugal force acts upon the gas to increase the diameter at the equator where the speed is maximised." - Kurt Thrust current Director of the Jodrell Plank Observatory.

Mu Serpentis - or is it though?

 

Image acquired with the Star Adventurer mounted 66mm Altair Refractor, the new 500 lines/mm spectrometer and the QHY5-11mono camera. Credit :Jolene McSquint-Fleming.

Calibrated Line Profiles and Reference Profile for an A07 class star together with a stretched coloured Synthetic Spectrum Strip. Credit: Jolene McSquint-Fleming.

New 500 lines/mm spectrometer designed and constructed in the Observatory clean room by Jolene McSquint- Fleming the JPO's Instrumentation Engineer.

"The weather continues to be very unfavorable for astronomy, with high level cloud preventing us imaging the gas giant planets Jupiter and Saturn. 

Over the summer, Jolene has addressed some of the optical aberrations associated with using a 500 line diffraction grating as a simple filter cell.  We did not want to permanently adapt the QHY5-11 camera for spectroscopy and so designed a 3d printed block to allow it to be brought very close to the imaging chip at the optimum angle for a first order spectrum at 550nm. This appears to have minimised 'fish tailing' of the spectral image and aided obtaining focus upon the spectrum rather than the star. 

On the 7th of July 2021 we tried the new spectrometer out using the 66mm Altair Astro refractor.  As the sky was quite light, only a few stars on the meridian were visible to the naked eye, so we chose one at random for the trial.

One of the not immediately appreciable downsides of using a 500 line diffraction grating is that, as the spectrum is more spread out than when using  a 100 or 200 line grating, it produces a significantly dimmer image. Possibly this will be improved by using the 127mm refractor, by stacking more light frames and by taking darks and flats. 

We prepped the spectral image using the freeware IRIS and then had a go at producing an initial calibrated profile using the excellent BASS software. The Observatory is indebted to the generous, skilled and intelligent individuals that devise and collaborate in the development of scientific software which is made accessible for free use. Thank you Christian. B and John. P!

Having obtained a profile we guessed, from the presence of strong Hydrogen Balmer lines, that the star in question is an A type star. We then used Stellarium to look for bright  A type stars that were observable to the naked eye and to the south near the meridian on 07-07-2021. The best candidate  is the A07 star Mu Serpentis.

Next up we intend to:

Image Vega and obtain a camera response curve for the set up.

Become more proficient in the use of BASS software.

Complete a half constructed 3d printed 100 lines/mm spectrometer for obtaining spectra from fainter stars.

Come up with a rudimentary grating design to address extended objects of interest.

Experiment with a fibre-optic link between the telescope and a spectrometer." - Kurt  Thrust current Director of the Jodrell Plank Observatory