Ghost Rings

It’s been a frustrating few months here—cloudy skies, a rainy spring, and the usual march of obligations that come with being back in the office. But I managed to sneak in a planetary session one Thursday morning before work. Not easy when you’ve got to be clocked in shortly after 6 a.m., but sometimes the sky gives you a narrow window, and you take it.

This was my first planetary observation in quite a while. I had the 10-inch f/6 Newtonian out, laser-collimated and ready. Saturn was hanging low and I didn’t have the time to work the ADC into the train, so I kept things simple. Seeing hovered around 6/10, transparency worse—perhaps a 4/10 thanks to persistent Canadian wildfire smoke over the mid-Atlantic.

Still, I managed a “deep red” imaging run, capturing Saturn shortly after its recent Autumnal Equinox last month. What struck me most when I finally got the planet centered and focused on the laptop screen was how dim the rings appeared.

At such a shallow B ring angle, the rings appeared ghostly, dimmer than I recall seeing them in years. On the laptop, they seemed to fade into the background, lacking the sharp border that can help in achieving focus. Visually, through the 10" at 187x, they were brighter—a shining needle skewering a ball of yarn—but still far from their previous brilliance.

So why the dimming? Some research was in order, and I must admit having AI as an assistant for such things is fantastic.

With us just past equinox the Sun is illuminating the rings edge-on. At this angle, the sunlight strikes the rings so obliquely that their icy particles scatter much less light toward us—especially in red and IR wavelengths. Unlike the globe, which reflects more consistently reflects the light back at the observer, the rings become dramatically muted under these conditions. And with the B angle so close to zero, we’re seeing not only less illumination but also less material: the thin plane of the rings reveals little vertical structure from this 

Interestingly, the rings looked darker than my last deep red image back in January of this year when we were still viewing the northern plane, despite having a similar B angle. The geometry and light-scattering behavior are that sensitive.

As for Saturn itself—the image shows subtle bands representing the NEB and SEB bands, and, interestingly, perhaps a darker SPR region. Overall it’s a small win in less-than-ideal conditions. This isn’t the showiest Saturn I’ve captured, but it’s a subtle reminder of just how dynamic the outer planets can be—not just from year to year, but from month to month in our own observing windows.

Mounting Problems

A few weeks ago, I was inspired by an ALPO webinar on daytime observing of planets, so I decided to try locating Mercury during it spring western elongation. Equipped with my Celestron CGX-L mount, I had high hopes of using its GoTo functionality for enabling me to find the planet amid the bright blue sky. However, what should have been a straightforward task quickly turned into a puzzling challenge. When I keyed in the time—just a little after noon—the mount's computer inexplicably believed it was just after midnight. As a result, daytime targets like Venus and Mercury refused to appear in the GoTo menu. After triple-checking every input and even rebooting the system multiple times, I felt equal parts baffled and frustrated.

Needing to get to the bottom of this, I opened a support ticket with Celestron. Their team responded promptly and suggested I double-check whether I was selecting AM/PM properly. While that might seem like a simple oversight, I assured them this wasn’t the issue—I had been meticulous in my entries. Notably, if I set the time to 11 a.m. instead of 12 p.m. the menu would display the expected roster of daytime planets in the sky.

The recommendation came back to update the firmware. Sounds easy enough, and there was even a link to a user’s video showing how to do it – but his mount and mine were different. Without the gory details it proved to be a process that I had to retry a couple of times before I got it right. And then, following the firmware upgrade, another issue arose where the scope would not properly return to the Home position. Another round of correspondence ending in a helpful call where the technician talked me through that issue and finally brought full resolution.

Though the experience was undeniably frustrating at times, I felt appreciation for the support Celestron provided. Their willingness to actually get on the phone and guide me in resolving the issue renewed my confidence in the brand and their equipment. Now with a little luck the next time Mercury has a decent elongation in the morning sky everything will work as expected!

The evening of the recent Lunar eclipse brought to light yet another technical snafu, this time with my iOptron HEM27 mount that I use with my Vixen scope. I planned to align the mount as soon as Polaris was out, but the iPolar software had other ideas. I’ve used it many times in the past with good results but that evening it would not display the crosshair that one must align to. Worse, the software was also crashing at times. I went with a manual alignment which worked well enough over the course of the frustrating evening which ended up in clouds engulfing the Moon moments before totality arrived.

About a week later I tried troubleshooting it. I first confirmed that the problem could be reproduced. Then I tried uninstalling and re-installing the software. Nothing worked and the software crashed upon each attempt. The next day I opened a ticket with iOptron.

Following guidance from the company, I downloaded and successfully applied a firmware update and took a new dark frame as suggested. However, to my disappointment, the core issue remained—iPolar continued to crash upon clicking the "Confirm Position One" button, as shown in a video I shared with them. I also ensured to clear the "Center of Camera" settings before testing further.

In response, iOptron Support requested details about the specific iPolar version and firmware I was using, directing me to check through their provided link. So, the back and forth continues without resolution. I am hoping that it can be resolved soon and certainly without having to send the unit back to the factory. The troubleshooting process with iOptron serves as a reminder of the challenges and patience required in astrophotography, where technical hiccups can cause you to miss opportunities to gather those photons.

 

 

Carbon Capture

A few weeks ago I found that my iPolar software in my HEM27 iOptron mount was routinely crashing when trying to perform polar alignment. The latest missive from tech support suggested that I should update the firmware. So with a clear sky and open schedule I took the opportunity to finally apply the update and re-test the software. Sadly, and a bit frustratingly, it still crashed when trying to do an alignment.

Despite the technical hiccup, I decided to pop on the Vixen and start an observation session with the objectives of evaluating the new (to me) 13mm TeleVue Delite eyepiece purchased at the HAL Christmas Party auction and visiting some items on the AL Carbon Star observing list. The sky was devoid of moonlight, offering seemingly clear visibility with a thin haze. Orion was dropping below the western tree line while Boötes was yet to climb over the roof from my backyard vantage point.

To keep it simple I elected to visit three carbon stars for the evening’s itinerary. Carbon stars are a fascinating subset of stellar objects that capture the interest of many amateur astronomers. These stars, characterized by their deep red hues, have atmospheres containing more carbon than oxygen, leading to the formation of carbon compounds that give them their distinctive color. The attraction of carbon stars lies not only in their sometimes striking appearance but also in their varying luminosity. They lend themselves well to the skies often encountered by the suburban amateur astronomer.

My first target was Y CVn, a carbon star in Canes Venatici, also known as “La Superba.” Despite the challenges with the iPolar alignment, the accuracy of the pointing allowed me to use the Slew & Center function efficiently on Cor Caroli. Upon keying in the coordinates for Y Canis Venaticorum, I inspected the field at low power and immediately identified the star by its red tint compared to other field stars. Switching to the 13mm eyepiece enhanced the color slightly, but the sparse field and light pollution subdued the redness. In comparison, I recalled Mu Cephei and Hind’s Crimson Star as being more striking.

Next, I attempted to observe T Cnc in Cancer. Using the Sync to Target function after slewing to Mars, I fine-tuned the positioning and centered the object. Initially, the field appeared pleasant but lacked any sun with the characteristic cerise coloration. Increasing magnification to 46x revealed a star with a slight hint of red, which I am guessing was T Cancri. Its faintness (probably at around 9th magnitude according to current AAVSO observations) likely made it challenging to detect its red coloration distinctly. It’d be worth targeting again with either a larger aperture or maybe from a darker sky.

After my challenging observation at T Cnc, I bid the scope to move a couple degrees to neighboring carbon star X Cancri. This time the low power view, a field busy with stars of a wide range in brightness, quickly revealed one breaking the monochrome black and white palette with a distinctive ruddy glow. Again, the 13mm eyepiece offered a better view at 46x by darkening the background a bit to increase the contrast a tad. To my eye this one is similar in brightness and redness (maybe even a slight bit ruddier?) than La Superba visited at the start of the session. That along with a more interesting field makes this a nice addition to the Astronomical League’s Carbon Star observing program.

Observing carbon stars for the suburban astronomer requires a little patience and modest equipment to work with their faint luminosity and distinctive color which can be obscured by light pollution or a sky lacking good transparency. Nevertheless, the pursuit of these celestial furnaces nearing their end of life certainly can be a rewarding endeavor and a pleasant evening’s celestial pursuit.

Eclipse Cloudout

A couple of weeks ago, the Moon’s orbit carried it into the Earth’s shadow during the early morning hours of March 14th. This eclipse was ideally positioned for those of us in the United States, so I was excited and hopeful to have a chance to witness it and capture some beautiful shots during totality.

I started monitoring the weather forecast in earnest on Thursday morning. The sources didn’t agree much. Underground Weather and WeatherBug predicted a significant cloud deck, whereas Astropheric and Clear Outside were far more optimistic. It seemed like an offshore system might creep westward and potentially cloud us out. The pattern suggested it might be advantageous to try and outrun the clouds by heading to western Maryland or West Virginia. However, since that wasn’t a sure thing, I opted for the comfort and convenience of watching from my backyard.

I downloaded and set up the Lunar Eclipse Timer and Camera Controller (LETnC) application the day before. I had used the solar eclipse counterpart to this software during last year’s Total Solar Eclipse, so I was hoping to leverage it for this lunar eclipse. I ensured that both my Canon Mark II and Canon t6i had charged batteries. The former would provide nice views of the full Moon through the 80mm Vixen telescope, while the latter could be used for a variety of shots with the 300mm telephoto lens.

Around 9 PM, I brought the equipment out from the garage, aligned the mount, and balanced the Vixen on it. The iPolar was acting a bit quirky, so it took longer than expected—I even rebooted and reinstalled the software to no avail. Fortunately, there was plenty of time before the eclipse would start, and the rough alignment provided by the glitchy iPolar would suffice.

As we approached the point where the Earth’s penumbra began to creep onto the disk, I took a shot of Luna in her pre-eclipsed state. I noticed some very high, thin clouds creating a slight glow around the Moon, but through the telescope, their impact was negligible. Although chilly, the seeing seemed fairly good—around 5/10, with transparency at about 6/10.

Uneclipsed Moon

Slightly before midnight, the Earth’s outer shadow touched the Moon. However, as usual, the effect was too subtle to see. Only when we got within about 15 minutes of the first contact with the darker umbra could one begin to appreciate a darkening on the Moon’s limb. By C1 at 1:09 AM, the clouds were slowly thickening, but not enough to seriously impact the spectacle or my photography.

A few minutes after C1

Over the next hour, I continued to document the encroaching shadow, re-centering the Moon in the Vixen and hopping over to the telephoto setup to reel off a few bracketed shots. Unfortunately, the cloud cover seemed to be matching the depth of the eclipse, gradually but inexorably thickening as the minutes ticked down towards totality. I had to edit the LETnC script to make the exposures a little longer, and it became clear it would be a race to see if the clouds would win out and block totality. A look at the satellite infrared image was not at all promising, with offshore clouds pushing into our area.

About 30 minutes before totality

By a little after 2 AM, it was clear that the weather had won this round. As the Moon was further engulfed in shadow, it was first lost from eyesight, and then even the telescope's light-gathering advantage was overwhelmed in my effort to continue photographing the eclipse. When C2 arrived a little before 2:30 AM, there was nothing to see, and the hope of witnessing the beautiful coppery orb floating in the spring sky slipped away along with the Moon.

I retreated inside to rest a bit and set an alarm for 3 AM, just in case the clouds relented. But when I checked the window, there was still no hint of the Moon in the sky, so I turned in for the night. Interestingly, some other members of HAL went out to Alpha Ridge to view the eclipse, and their skies held clear enough up until totality to capture some nice images. And so it goes in this often-frustrating hobby that depends so heavily on having a clear sky above!

Leveraging Starlight for Sharpening Planets

The field of digital planetary imaging is where art meets science, particularly in post-processing. After using our preferred tools to distill a video of several thousand frames into a stacked and aligned image, there is still much work to do. We need to refine it into a sharpened view of the target before applying some tweaks in a program like Photoshop. To achieve that sharpened image, we have two techniques at our disposal: wavelet sharpening and deconvolution.

Wavelet sharpening is a key feature of the freeware application Registax6, a staple of planetary imagers for many years. The author of the software, Cor Berrevoets, has not issued an update to the venerable program since 2011. He has, however, created a successor in the form of another freeware application called waveSharp. Both of these tools decompose the selected image into layers - from large-scale components of the image to fine scale. By adjusting the sliders, you can selectively enhance these aspects of your image. The finer scale adjustments must be done with a light touch to avoid introducing significant noise to the final result. Fortunately, one can combat the noise by suppressing the finer scale adjustment.

The ability to apply deconvolution is appearing in more tools for the planetary imager. One excellent new addition is the Lucky Stack Worker (LSW) freeware application (a video by the author, Wilco Kasteleijn, is on the ALPO channel). Another is AstroSurface, an application with extensive filters and functions for not only the planetary imager but the deep sky enthusiast as well.

So, what is deconvolution? In brief, it is using a contemporary representation of an Airy disk to help recover detail lost through atmospheric turbulence, soft focus, or optical issues. Under perfect conditions, when examining a moderately bright star, you would expect to see a small disk with diffraction rings emanating from it, known as its Point Spread Function (PSF). The interface on the LSW has two checkboxes - one for "Deconvolve" and one for "Sharpen" (i.e., wavelet sharpening). If we select the Deconvolve and select the "bullseye" adjacent to it, we see that LSW is offering us a synthetic PSF with sliders to allow us to adjust it.

Impacts when adjusting the Seeing Index slider

You could take a few minutes before or after your imaging run to inspect a nearby star and make a note of its Airy disk appearance to emulate it in the synthetic version. But why not record an image to capture the PSF for that particular imaging session? This is exactly the sort of thing that Wilco Kasteleijn advocates in the LSW manual and references a nice article by Marco Lorenzi on how to do this.

A couple of nights ago, Astropheric was displaying that the seeing would be "average" with temperatures in the 40s, so it was an opportunity to try this technique and maybe gain some experience acquiring a PSF image to leverage in my processing. Like a deep sky flat frame, the PSF image should be taken with the same imaging setup and without pointing the telescope too far from the target.

My first attempt using a star near Jupiter did not yield results, as it ended up being too faint and requiring a longer exposure. That, in turn, blurred the Airy disk by its scintillation. For Mars, I targeted a brighter star and had more success with a frames-per-second rate nearing 100. Even so, it is challenging to get it right; in retrospect, I should have lowered the gain further to avoid "blowing out" the Airy disk.

The PSF image taken during the imaging run

So, here are the results! Even with only a fair PSF image processed by Autostakkert, the LSW did a nice job of recovering the details from what turned out to be sub-par seeing. Applying sharpening and denoising to the image resulted in a reasonable, if not admirable, image showing albedo features, the polar cap, and likely cloud features.

To me, this technique of capturing a PSF image as part of the Lucky Imaging session holds great promise. As a final note, here is a Copilot-assisted comparison of how these two techniques help us achieve fantastic planetary images.

Chasing Planets: January's Observations and Challenges

The media has been hawking the auspicious "planetary parade" that allows an observer to see 6 planets during frosty January evenings. Of course two of those (Uranus and Neptune) are not naked eye objects. I do not mind articles that generate interest in our hobby, but my fear is always the "over promising and under deliver" risk.

However, January was indeed a fun month for us planet observers. Mars was occulted by the nearly Full Moon on the evening of the 13^th, and then two days later came to opposition for this apparition. Jupiter was positioned well and decided to throw a major eruption amid its North Tropical Zone southern jet stream on January 10^th, garnering a lot of attention. Venus also ascended the Zodiac after lying close to the southwestern horizon most of its current evening apparition, reaching greatest elongation on the 10^th heading for its highest altitude in the western sky on February 2^nd. The only downside has been the weather with classic winter turbulent seeing amid very cold temps.

Mars Occultation

The skies were clear but quite cold for the occultation of Mars. I set up the 10" Cyrus telescope and verified its collimation. The Moon served as a convenient focus target as I set up about 20 minutes before the scheduled disappearance. I knew that the difference in brightness would be a challenge and thought I'd have time to fiddle with the gain setting right before the occultation, but it happened so fast that I really did not get a great capture with the Moon very overexposed. Still, it was a very cool event to watch the Moon relentlessly approach the red orb and cover it up with about 30 seconds.

The Moon ready to cover Mars

January 17th Session

The evening of the 17th was predicted to have average seeing and temperature right around the freezing mark, which is fairly good for this region in winter. I again set the Cyrus scope out early to cool and verified its collimation. As Venus emerged from encroaching twilight I set to work on capturing our sister planet. 

Starting with the Deep Red filter (642+nm) and no Barlow, Venus provided a bright target upon which to focus. Doing a 5 minute capture resulted in a nice image, showing the planet past dichotomy and a common cue-ball appearance. I have yet to truly discern any cloud details in IR light.

Swapping out the Deep Red filter for an IR-block and UV set, I retargeted the planet and adjusted the settings to bring up the brightness in the fainter UV light. I could make out even on the on-screen image that there was uneven brightness in the sunlight reflecting off the Venusian cloud tops.

Processing produced a nice greyscale image with a some cloud structure. Interestingly, a well defined cusp cap was not really seen, although you might argue one was around the south pole region. This is somewhat in agreement with the UV Venus images I have been seeing submitted to the ALPO for the current evening apparition; cusp caps are not as prominent as I believe they were during the last apparition.

By now Saturn was visible in the deepening twilight, close and to the left of Venus. I figured why not give it one last capture since the upcoming mid-March solar conjunction and my obstructed western horizon meant it would soon be inaccessible. I added the Barlow back into the imaging path and returned to the Deep Red filter. Seeing was not very good, and the rings had closed up again compared to a few months ago. I had enough juice in the laptop for two 2-minute captures, resulting in a sub-par image where it is hard to even detect the globe's shadow being cast against the rings. Au revoir Saturn - until we meet again in the late spring!

Getting the AC adapter hooked up to the laptop I next swung over to Jupiter. My hopes were to get multiple captures into the evening if the weather held, recording not only the very recent North Tropical Zone southern jet stream eruption but also that continually expanding disturbance in the South Equatorial Belt that started back in November.

The seeing ended up being fairly good over the course of about 5 hours, allowing me to capture a lot of interesting features, including that NTrZ outbreak. As we began to close in on midnight the gods conspired to end my run as the cirrus clouds began to thicken and the tracking on the Celestron mount suddenly had a stall (it is always amazing how quickly the planet exits the frame when this happens). Rather than fight to recenter and continue amid the deteriorating seeing and transparency I decided to wrap things up on Jupiter.

In the middle of my Jupiter captures I had to take a break due to the location of the planet. When an object is high and near the meridian, the Cyrus telescope tube runs up against one of the tripod legs. The resolution would be to raise the tube up off the saddle, somewhat like extending with a pier. But that would be a lot of effort and so is not likely to happen in the near future (if at all). 

But rather than waste the time I opted to do a run on Mars which had just passed opposition a few days earlier. While at only about 13" in size the disk was large enough to take in some nice albedo features such as Syrtis Major setting and Sinus Sabaeus and Sinus Meridiani on the central meridian. The NPC was also a brilliant white and was a good feature to leverage in trying to get the best possible focus. Hopefully I will get in a few more sessions with Mars for this apparition, but it's going to shrink in size quickly now that it is past opposition.

While I did not achieve all my goals for the evening (I missed seeing the SEB disturbance on Jupiter), it was quite a good night for the middle of January. It reflects why planetary observing provides such a rich experience for the amateur astronomer.

December Planet Parade

While it is nice to see a planet coming to opposition in the northern part of the zodiac given the much higher altitude it then attains in our skies. But while the planet heads north, our opportunities of good seeing go south. The heat of the day radiating into the atmosphere sets up turbulence and often results in poor seeing. It also seems that the winter months are more overcast. This year I went 51 days (late October to mid-December) between observations - not great! 

Uranus - December 18, 2024

At the start of the year one of the astronomy goals I had set was to image Uranus with its moons. I tried a couple of times earlier in the fall without success, but finally on the night of the 18th I got the SharpCap stacking working with Uranus as the target. I had to keep the region of interest (RoI) wide because otherwise the software complained of not having enough stars to align. I played with the exposure and gain to finally generate a nice stacked image that clearly showed some of the moons.

Using some post-processing tools to enhance the raw stack resulted in a fairly satisfying result. The Sky & Telescope online tool that shows where the moons are in relation to the planet was helpful in orienting the shot. I ended up capturing 4 of them (Titania, Oberon, Ariel, and Umbriel) - Miranda was probably lost in the glare of the planet. Maybe next time I'll try to include the Barlow in the imaging train to gain some more space between the planet and moon.

After that success I decided to focus on trying to capture the planet without overexposing it. For this run I did WL with an UV/IR cut filter. Uranus is very difficult to pull out details, and those usually require an IR wavelength and larger aperture. The ending result was perhaps a bit more blue than I expected, but overall definitely the best image of Uranus I have been able to produce.

Jupiter - December 23, 2024 

Just a couple days before Christmas the evening sky was clear but cold, but with predictions of average seeing so I thought I'd set up the scope. I was amazed to find that the seeing was actually above average as I dialed in Jupiter. I started off with a series of WL runs using the Cyrus 10" f/6 and a 2.5x Barlow. 

In between Christmas Eve activities the next day I found a little time to do some processing of the captures and was quite happy with the outcome. Oval BA was almost on the meridian, far easier to see than last year with a pale tan coloration. Out ahead of it was long enduring oval A8. The SEB had some spots of darker material, but my general impression is that the belt is weaker than it has been the last couple of years. The EZ had a lot of material swept into it from both NEB and SEB, presenting almost like latte foam art crafted by a talented barista. The NEB had a small, intense outbreak midway between the following limb and central meridian. 

I also ran a set of CH4 captures since the seeing was above average. As to be expected, BA was the most prominent object at that wavelength.

Mars - December 23, 2024  

By this time Mars had cleared the neighbor's tree and was an enticing target. I did several runs in WL with high hopes of getting a good capture. After four 2-minute runs I swapped out for the R+IR filter, but the laptop unfortunately cut off due to low power after only one capture.

Processing after Christmas showed a well-formed NPC with a "Lowell Band" around it comprised of Propontis II and Utopia. There definitely were some clouds around the south pole, and M. Cimmerium was well placed. In the center was the Elysium area which seemed to show as an elevated area more strongly than I recall previously. The single R+IR shot was also worthwhile, demonstrating how the longer wavelength can sometime bring out additional details, such as the subtle Gomer Sinus extension off of M. Cimmerium.

Overall, quite a nice way to wrap up 2024. It was another enjoyable year with lots of activity, from a Total Solar Eclipse to a pretty good comet. Hopefully 2025 will bring more clear nights and interesting features to enjoy!