March 2023 – IMT3b Observatory

Viewing report 8th & 9th March 2023 Tenerife Los Gigantes Villa

Between 9pm and 12:30am both nights

A week with the family in Tenerife afforded me the opportunity to test out for the 2nd time this year the Skywatcher 100 Esprit on the AM5 harmonic mount with the ASIAIR in control and the ASI2600MC with a new Antlia Triband RGB Ultra filter.

Over the period of the week I picked 2 nights when I wanted to observe. Because of the clement environment of Tenerife and the Canaries and unlike the UK, you can decide when to go out and image as almost all nights are clear, the weather warm, around 22 deg Celsius and the bed not that far away from the pool. Given when we were on holiday which was decided around other activities, the Moon phase was Full.

The one problem with renting a villa is when the owners will not pinpoint where on a map it is. There is normally a reason. In this case it was because of the proximity of the local sports buildings. A swimming pool to the front of the villa including a floodlit pitch and 2 more flood lit pitches to the left and right of the villa at the rear.

So yes it was bright, very bright, as can be seen on the villa party wall.

So given all that light pollution I was then pleasantly surprised how well the final image came out of the singular target I chose. NGC 2244, the Rosette Nebula.

I exposed for some 75 x 300s over the 2 nights. All the images were on the West side of the Meridian to make it easier without a flip.

I found stacking 75 images instead of just the first night of 30+ images gave a much smoother background and nebula, much less noise and easier to work with the data.

So not a bad photo for Full Moon and 3 flood lit pitches. I look forward to testing out the kit at the top of the mountain later in the year under New Moon dark skies.

Viewing report & Filter Comparison 8th March 10pm 2023

I wanted to compare 2 filters this evening as I have recently purchased the new Antlia Triband RGB Ultra filter. The original filter I had for the one shot colour was the ZWO Duo-Band filter.

As can be seen above the difference without a filter is quite dramatic (Top – No Filter, Middle – Antlia Triband RGB Ultra, Bottom – ZWO Duo-Band). There is more broadband light captured. The red nebula is less apparent and the background sky is much brighter.

The above image from the running man nebula, NGC 1977 demonstrates that without a filter a reflection nebula comes through best (Left – No Filter, Middle – Antlia Triband RGB Ultra, Right – ZWO Duo-Band). The ZWO filter gives a more green image over that of the Antila, which in itself reduces the reflection nebula but does start to pick up some of the red emission nebula within the Running Man.

The inverted background above gives a sense of the reduction in star luminance that is allowed through without a filter.

This image shows the background with the details of the readout from each of the pixel across the colour channels. Here you get a sense of the green seen in the ZWO filter is less the extra green coming through, moreover the lack of blue being allowed through. Without a filter the background sky is swamped with all colour channels.

With no filter the full effect can be seen above, much brighter background, nebula less colourful and less detailed.

With the Antlia filter above, the final single image I personally find is much more pleasing.

Finally with the ZWO filter you can see quite clearly the green effect.

So in summary I would say the ZWO filter is better than no filter except when imaging reflection nebula, however the best filter is the Antlia filter when paired with my one shot colour ZWO ASI2600MC camera.

Below is a random drawing of a scientist with a Tak laser beam.

Venus & Jupiter Conjunction (02/03/2023)

At 18:15 I decided to grab the SkyWatcher Heritage 150 baby Dobsonian and setup it up in the back garden to view the Moon and the conjunction of Venus & Jupiter that were following the setting Sun in the West.

My neighbour saw us in the garden and asked if he could pop over and take a peek. In the 25mm eyepiece we could fit Venus and Jupiter in the same field of view. Venus was way too bright for me to see the slight phase (85.5%) but with Jupiter the two main belts and three moons were clearly visible. In the 10mm we could make out the main four moons with ease.

Moving to the Moon we used both the 25mm and 10mm eyepieces to view the craters on the shadow terminator. We tried to grab a mobile phone picture but the baby Dob really isn’t up to the task and all attempts were disappointing.

Using the Televue x3 barlow and the 10mm we could see craters in the shadow terminator nicely along with Clavus and the craters within.

10mm & 3x Barlow simulated view (Credit Stellarium)

Although the baby dob is great for grab and go I feel that SW 8-inch Dobsonian with a really good eyepiece would have done Jupiter more justice but hey the views were good enough and the experience enjoyable.