LUAstro Newsletter - March 2026
New telescope, new plans, new images, newsletter.
Welcome to LUAstro’s (slightly delayed) March newsletter! This month, we talk about our new SeeStar S30 telescope, our plans to fix some of our older equipment, and share some of the photos members have taken over the past month!
New telescope
The Society has collected a wide range of telescopes over the years - some of which belong to the Society itself, some by the Physics Department, and others kindly donated by members of staff.
Out of these telescopes, the three that are used the most often are our RedCat51 51mm f/4.9 Petzval Refractor, our Orion SkyQuest 16” f/4.4 XX16g Dobsonian telescope, and our Sky-Watcher 5” Reflector. Our Coronado 40mm Solar Telescope and the Celestron CGE1400 XLT 14” SCT kept in the Dame Kathleen Ollerenshaw Observatory are also occasionally used, with a lack of mounts and cameras limiting the use of the other telescopes for astrophotography.
Since it was first purchased around 3 - 4 years ago, the RedCat51 Refractor has been paired with our Sky-Watcher EQ6 Pro Mount to form the society’s only viable astrophotography setup; limiting the opportunity for society members to take pictures of their own on observing nights without using their own equipment. A couple of weeks ago, however, this finally changed as we purchased a new Seestar S30 telescope for the society, using funding from the university’s Students’ Union (LUSU).
We first tested the Seestar S30 on the Fish Head Nebula, a bright star-forming region within the Heart and Soul Nebula. We noticed that stars appeared blurred in the upper corners of the photo. At first, we suspected that this was due to collimation error in the telescope - rare in a refractor, but still possible. However, after testing the S30 on a few targets, we measured the sensor tilt, the difference in star size (FWHM) across all corners of the image, and found it abnormal. A sensor is tilted when it is rotated such that not all parts lie on the focal plane of the telescope, resulting in only some of the pixels being in focus. We think that the sensor tilt looks especially drastic in our Fish Head Nebula image because of field rotation.
Field rotation is the phenomenon where the target rotates in the frame throughout the night. Of course, all stars rotate around the north star due to Earth’s rotation, and we usually account for this by using an equatorial mount, but on the alt-azimuth mount of the Seestar S30, a target may be imaged by different parts of the sensor throughout the night, which results in much of the final image being plagued by sensor tilt. When we mount the S30 equatorially, we will find that the defocused region of the frame will remain confined to one corner, which is much more manageable.
New plans
Alongside the SeeStar S30, we also purchased a variety of smaller pieces of technical equipment to repair and upgrade our older Losmandy G11 equatorial mount to function with GoTo controllers. As mentioned earlier, we have several telescopes that are have a limited use for astrophotography due to a lack of cameras and mounts; including an 11” SCT that was donated by Dame Kathleen Ollerenshaw back in 2001.
After it was replaced by the 14” SCT currently kept in the observatory, this telescope has seen little active use - mainly due to the lack of a usable mount to put it on. For astrophotography, a GoTo equatorial mount is essential for taking longer-exposure deep-sky images - something that the 11” SCT’s excellent aperture is fantastic for - and something that the Losmandy G11 mount could be easily converted into.
If fixed, this would suddenly increase the number of usable astrophotography setups in the Society from one to three, and allow multiple members to take more detailed deep-sky images during observing nights, purely using society equipment.
Additionally, after conversing with a member of the IT services in the Physics Department, we now have Siril, StarNet, and GraXpert (some excellent beginner-friendly processing software) on all the computers in D503 and Astrolab! Together, this should hopefully allow members to not only learn and take astrophotography images, but to fully process them too.
New images
Now it’s time for some images! We haven’t taken as many images as we did in February this month, but we still have some that are well-worth sharing.
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