by Neil Martin, Pat Devine, Douglas Heggie, Ramsay McIver, Mike Christie
Banner image: M31 Andromeda Galaxy captured using the DWARF II Smart Telescope. Neil Martin

Introduction

The smart telescope wave is showing no sign of attenuation. Over the last 12 or so months, each vendor has either released a new product, or has publicly announced their intent to continue developing the existing one. And, the “traditional Astro imaging” community is still divided as to whether these devices help or hinder. The fact that one of the market leading companies has now made their initial play – albeit with a luxury end offering – gives some clue as to where things are heading.

However, after you’ve spent minutes, or perhaps hours – but not many – “just imaging”, perhaps doing a little offline processing, then sharing your results (and yes, some frustrations too!) with your family, friends, social media stream and the Astro community in general, what’s next? By that, I mean what’s next beyond simply keeping up with developments and enlarging/refreshing your smart scope collection?

Neewer video tripod with adjustable ball head. Neil Martin

After “just imaging”, is there anything more?

Accessories

First of all, there are a few small, and usually inexpensive, accessories that you can add to your smart scope, to either make setup and usage even simpler, or to enhance the images.

Adding a more substantial tripod might be top of this list – it enables the scope to be placed higher up, and increases the stability when there is a breeze about. Others have even added “domes” to afford further protection! When levelling is important – as is the case with at least one of the devices – then either a small leveller adapter, or a fully adjustable ball/video head, can make this process easier.

Oak Astro 3D printed accessory pack for the ZWO Seestar S50, including filter adapters, lens cover, light shield, star spike and Bahtinov mask. Neil Martin

Achieving the best possible focus is crucial to the final image quality. The auto focus capabilities provided by smart scopes are continually improving, both in terms of accuracy and speed. However, manual focus is also available, and use of a focus mask (the Bahtinov Mask is most common type, but others are available) is helpful here. Note that a filter/mask adapter may be required, and that these may not be readily available for all scopes.

In a similar vein, diffraction spike masks can be added – to the same adapter – to give your stars a pleasant “starry spike pattern”. Beauty is in the eye of the beholder here!

The same filter adapter can also be used to mount external filters – both 1.25 and 2 inch varieties – to produce results which vary from those created using the internal filters. There are a wide range of specialist filters available. The price range is equally wide!

EQ Mounting

SkyWatcher Star Adventurer Wedge, which enables convenient EQ mounting for a Smart Telescope. Neil Martin

All of the smart telescopes on the market (at the time of writing) are supplied with an alt-azimuth mount. This means that the effects of field rotation must be considered during the imaging process. The majority of the time, the effect can simply be cropped out of the final image. However, where longer exposures or sessions are desired, or the target fills the frame, or is near the zenith, cropping may not be sufficient. The solution to this is Equatorial (EQ) mounting. Neither the smart telescope hardware, nor the app software, is designed with this in mind. Furthermore, when operating in EQ mode, any imaging platform requires accurate polar alignment – and again, smart telescopes are not designed to support this. Nevertheless, there are several examples of DIY EQ mounting, and the addition of accessories or methods to support polar alignment – for some smart scopes.

For experienced imagers, the additional complication and effort necessary may produce improved results, but there is an argument to say that much of this is simply to prove that such a thing is possible. Even with a working DIY EQ setup, there remain additional constraints, as the smart scope is not really pointing where it thinks it is. With all this said, one of the forthcoming new products promises an ‘EQ mode’ which, if implemented well, might encourage other manufacturers to follow suit.

NGC6692 captured using a ZWO Seestar S50 Smart Telescope. Pat Devine

Citizen Science – Hunting Outbursting Young Stars (HOYS)

HOYS is a citizen science project run by an academic team from the Universities of Kent, St Andrews and Dundee. It aims to observe nearby young clusters and star forming regions visible from the northern hemisphere to study their variable young stars. The difficulty of getting sufficient time on large professional telescopes, to perform long-term monitoring of objects, creates opportunities for amateurs to make a real contribution.

The HOYS targets have been chosen so that they are already of interest to astro-imagers. The minimum aperture for HOYS data collection is 50mm, making it accessible for some smart telescopes. These smaller scopes are ideal for measuring the brightness of brighter stars, which can easily become saturated when using larger telescopes. When the smart telescope generates pre-calibrated files during its data capture process, this simplifies the steps required to prepare and upload data to the HOYS server for later processing.

With just a small additional effort, it is possible to create scientifically valuable data as part of normal imaging activities. In this example, there is an opportunity to make meaningful contributions to the scientific study of star formation!

HOYS Lightcurve of the Week with Seestar

The distant periodic comet 29P/Schwassmann-Wachmann 1, captured using a ZWO Seestar S50 from suburban Edinburgh. The comet is the faint, centrally concentrated spot in the middle, at magnitude 13.8. Above right is the star mu Cancri, magnitude 5.3. The image was made by combining 332 10-second exposures. The motion of the comet was very slow, and so the stars are not trailed. Douglas Heggie

Citizen Science – Comets

From a suburban garden, the “limiting magnitude” of an average smartscope may be about 15. Fainter stars can be detected, but about 15 is the faintest magnitude which can be reliably measured. This will vary a little, based on location and local lighting conditions.

Comets are not stars, but more-or-less extended objects. Still, they can be detected (and their total magnitude can be measured) down to the limiting magnitude.

The periodic comet 12P/Pons-Brooks captured using a ZWO Seestar S50 Smart Telescope from Aldclune, Perthshire, Scotland. The image was made from 101 images, each exposed for 10s. They were combined in Siril in such a way as to compensate for the motion of the comet; therefore the stars are trailed. The gap in the star trails was caused by a brief period of cloud. The straight line above the comet is a satellite trail. The magnitude of the comet was 5.8 (measured with ASTAP free software), and the tail was almost 1 degree long. Douglas Heggie

That is enough for sending the observation to COBS (the Comet Observation Database), which is the standard international repository of such data for comets. Often a smartscope, with a modest aperture, records a fainter total magnitude than a telescope of larger aperture – because the smartscope cannot detect the faint outer parts of the comet. However, allowance can be made for this, as the observed size of the comet is also sent to COBS.

For brighter comets, a tail is often detectable, and its length and orientation (if available) are included in the records in COBS. Bright comets often appear in twilit skies, and here a smartscope can sometimes struggle, because it relies on detecting and recognising moderately faint stars, which are more difficult to detect in twilight. But, with care, the smartscope will often orientate itself well enough to point accurately at a cometary target, even if it cannot confirm the pointing by observation of faint stars.

Bright comets are beautiful objects, and smart scopes can yield impressive images.  It does require skill to produce top-grade results, showing the faint details in the tail against a sharp, black stellar background – but this can be a rewarding way to go beyond the basics!

Comet OBServation database (COBS)

Citizen Development

At a high level, the smart telescope is made up of several hardware components including the optics, the imaging system and the mount/drive. These are controlled using two software components – the device firmware and the user app provided by the manufacturer. When building these types of devices (and this applies beyond smart telescopes) it is common to introduce a layer of software to make things easier for the hardware and software to work together. This layer is known as an Application Programming Interface or API. Where the API details remain private, there is little that can be done by external or citizen developers – although that doesn’t stop some enthusiasts who see this as merely an additional challenge! However, where the manufacturer publishes details of the API, the tech-savvy user community jumps into action. Underpinned by social media communities, communication channels and cloud based repositories, collaborative software development quickly results in the creation of solutions which are beyond what the manufacturers thought necessary to include in (the current version of) their user software.

Dwarfium: A desktop application, which runs on Windows, and uses the DWARF II and Stellarium APIs to make a connection between the two, enabling easier imaging. Neil Martin

Dwarfium on Github

With only the hardware limitations as the restriction, solutions have been created to run smart telescope control software on Windows/MacOS/Linux devices to:

  • integrate planetarium software to make target selection easier
  • operation in EQ mode to enable targets below the scope horizon to be captured
  • visually catalog the smart telescope memory storage contents
  • create mosaics to allow imaging of a wider field
  • create an imaging schedule allowing for longer term control
  • manage connections to multiple smart telescopes at the same time

The only other limitation is the collective imagination of the developer community!

External Software Processing – Stacking

This is a topic in its own right – perhaps the next article in the series? – but for now, only the basic principles are relevant, to lead us into the final section.

The processing – often referred to as “stacking” – of Astro images requires different types of input frames. The frames containing the image detail are called the “light” frames. The other frames are collectively called the “calibration” frames. The stacking process involves getting as much information as possible from the light frames, whilst using the calibration frames to remove unwanted noise. The smart telescope does all of this for us, in real time, as it is capturing the image!

Post processing an image of M51 Whirlpool Galaxy captured using a ZWO Seestar S50 using Siril. Neil Martin

At the same time, the scope is also capturing and storing each individual light frame (some scopes require a user setting to be set to a specific value to enable this). After the session is complete, we can connect the scope to an external computer, download the individual light frames – and in some cases, calibration frames are also available – for external processing. The main benefits of doing this are the selection of software to do this job, and the fine tuning and special processing algorithms that these specialist packages support.

Finally, since there are now large communities of smart scope users around the world, connected by social media, there is the opportunity to share and combine light frames from many similar devices. The terms multi or ultra stacking describe this activity.

Post processed image of M1, the Crab Nebula, using 878 x 10s exposures captured using 3 ZWO Seestar S50 Smart Telescopes. Ramsey McIver, Mike Christie, Neil Martin

Multi or Ultra Stacking

The idea of sharing image data for processing for collaboration or education purposes is not new. There are a number of public sources of captured data available online. In some astronomical societies, members might also agree on a shared target and try to pool data, but will have to account for differences in equipment when doing so.

Therefore, there is an excellent opportunity to do more with data using a community of users, capturing the same target, but all with identical equipment. Once the data is shared, each user is free to use their own approach (software, techniques and process) to produce a final image.

Within the Astronomical Society of Edinburgh, we have experimented with a handful of users and targets, working with tens of hours of data, perhaps captured over a few nights. The different resulting images are amazing to see, and interesting and fun to discuss. We are certain to continue these Multi Stacking projects as our smart telescope community grows.

The reach of social media, and the rapid growth of dedicated online communities, connecting smart telescope users by brand takes this to another level. Almost immediately, many tens of users can contribute a collective hundreds of hours worth of data covering the same target. Now the only limitation is the processing power required to generate the final image! These Ultra Stacking activities are community-driven and give any owner the chance to be part of a shared experience.

DWARFLAB DWARF II and ZWO Seestar S50 Smart Telescopes ready for imaging. Neil Martin

Conclusions

There are likely several reasons behind the rising popularity, and therefore, ongoing development of the Smart Telescope market. The overall package, which delivers good functionality at reasonable cost; the ease of use, which gets more people imaging; the sharing of images via social media, which encourages both new and existing owners; are all contributing factors.

For many smart scope users, the satisfaction in creating “my own” image, whether this takes seconds , minutes or hours, more than justifies the investment. However, for those intrepid adventurers willing to boldly go, it is absolutely clear there are numerous opportunities to take things further – including contributing to extending the smart telescope platform itself.

Therefore, whether it is just for yourself, or as part of a society, or a scope-specific social media community, or even a public astronomical body – it is time to challenge yourself to go beyond the basics!

Appendix – Useful Links

Further information on accessories may be found at:

Oak Astro Seestar S50 Accessory Kit

Neewer Video Tripod with Adjustable Ball Head (Amazon)

Neewer Leveller (Amazon)

Examples of individual and multi stacked images are available on Flickr at:

M51 Whirlpool Galaxy
M51 approx 57 mins, Ramsay McIver
M51 on Flickr by Ramsay

M51 approx 6 mins, Mike Christie
M51 on Flickr by Mike

M51 approx 54 mins, Ramsay AND Mike
M51 on Flickr Combined Image

M1 Crab Nebula
M1 approx 43 mins, Ramsay McIver
M1 on Flickr by Ramsay

M1 approx 2.5 hours, Ramsay, Neil AND Mike
M1 on Flickr Combined Image

The following companies have developed one or more smart telescope products.

Celestron Origin Product Home Page

DWARFLAB Home Page

Unistellar Home Page

Vaonis Home Page

ZWO Seestar S50 Product Home Page