My equipment review part 2 : William Optics Zenithstar 73 APO

© 2019 William Optics

I’ve dabbled in astro-photography over the years, with ok results. I figured as astronomy is a life long endevour, I might as well put the time and effort in getting the right tools for the right job. I’ve sat in the middle ground, so to speak, with Schmidt–Cassegrain telescopes (SCT), so decided to go for a full on refractor. I also wanted to have a good spread on focal lengths from a 2800mm (EDGE11 HD) to a 1500mm (Celestron NexStar Evolution 6″) and now this provides me with a 430mm focal length. This type of scope uses convex lenses to present the light as you see it in your eyepiece.

Here’s a rudementary drawing I made of the basic workings of a refractor telescope

The William Optics Zenithstar 73 is a beautifully designed wide field refractor designed and built for the astro-photographer but serves as a great visual tool also. It’s nice and fast at F/5.9 and with a focal length of 430mm it provides really nice wide field views. It’s got a dual speed 2.5″ rack and pinion focuser which is really smooth. Another cool feature of this offering is that it has a built in Bahtinov mask allowing for pin point accuracy in your focusing.

Bahtinov Mask embedded into the scope

© 2020 astronomydiaries.com

I use this with a light astrophotography camera, so weight is not an issue, however, I feel WO could have supplied an extension tube with this scope, seeing as its touted as an astrophotography tool. An extension tube is needed to achieve focus. Luckily, I had a spare one, but not everyone will have this or realise they need one until they are setting up and cannot achieve focus.

1.25″ Extension tube. © 2020 astronomydiaries.com

© 2020 astronomydiaries.com

Visual observation with this scope is pretty good. For example, below is an image of how you can expect to see M42 (Orion Nebula) with an 18mm 82° field of view eyepiece and a 30mm 82° field of view.

image credit: © 2020 First Light Optics. https://astronomy.tools/calculators/field_of_view/

I didn’t purchase an additional mount for the telescope. I have a CGEM mount in good working order, it’s just a case of swapping out the tubes. I had a spare Losmandy style dovetail plate for an 11″ SCT, all it needed was a slight modification by drilling and threading holes and ensuring they were in a line dead center, the Vixen-Style Dovetail bar supplied with the ZenithStar 73 could be fixed to it and held securely on the mount. I used allen bolts for this as they easily fit into the recess on the vixen style bar.

Below image shows the set up secured in the jaws of the mount.

© 2020 astronomydiaries.com

William Optics 50mm Guidescope with 1.25″ RotoLock mounted on the ZenithStar 73

© 2020 astronomydiaries.com

The scope will take either a DSLR type camera or a dedicated astro-photography camera. If using the former be sure to have a 48mm T Ring mount for your Canon or Nikon DSLR which you can buy from any good astronomy equipment vendor.

I haven’t really had too many opportunities to put this to the test regarding imaging. I did however download the ASICAP software for the ZWO camera and is available for both MAC OS and Windows. I’ve been getting to know this and early impressions are good, I find it’s not too complex and I got up and going fast enough, of course it’s easy when you have a target like the moon, but I’ve also tried it out on the Hercules Cluster.

© 2019 astronomydiaries.com
© 2019 astronomydiaries.com

Field flattening is taken care of by using the William Optics Adjustable Flat73A. I had to play around some to get the focus correct, but it’s not too difficult. There’s some great information on using the field flattener on this page.

All in all, this a very easy scope to use, lightweight and portable. There’s an optional padded case available for this that will take some accessories too. I hope you found some parts of my review somewhat useful.

Next up….Celestron EDGE 11 HD

My equipment review part 1: Celestron NexStar Evolution 6

image credit: © 2020 Astronomy Diaries

Since there has been too few opportunities to observe lately, I thought I’d go through my gear, and while there are tons of in depth reviews all over the web, I’ll provide my own mini review on each bit of kit I’ve acquired over the years.

Currently, my most used scope is my Celestron Evolution 6″ SCT. I bought this due to the ever increasing light pollution in my area, so it serves as a nice grab and go scope for a trip to my remote dark site, for added protection I bought a padded aluminium case for it. It comes with a 1.25″ visual back and as I mostly use 2″ eyepieces, the first thing I did was to replace the supplied visual back with a 2″ one. I then attached a spare 2″ diagonal and was all set.

Celestron Evolution 6″ in packed snuggly in a padded case.

image credit: © 2020 Astronomy Diaries

You don’t need a battery for this as it already has a built in Lithium-ion battery, also it has 4 auxiliary ports and a USB port, so you can charge your phone etc. if need be. The Evolution series can used in two ways; via its built in Wifi and Celestron’s SkyPortal app (iOS or Android versions available and built on the Sky Safari software) or the supplied NexStar hand controller. But to me one of the biggest selling points is the ability to align and control this scope with an app. I use an iPad mini with the SkyPortal app, using this has made observing far easier and quicker, but (geek warning!!) most importantly has injected new levels of excitement into my astronomy.

However, before I settle in for a night of observing, the small matter of alignment needs to be carried out. I had been using the StarSense auto align device with an existing scope but had not used it that much and was considering selling it off until I got the Evo. Once I have the system fired up, set the OTA (Optical Tube Assembly) on the horizontal, the StarSense has the alignment done in a couple of minutes. This is also completed via the app, which brings you through each step.  The whole set up is really very easy.

© 2020 astronomydiaries.com

As mentioned, I have a 2″ diagonal fixed to the OTA and I really like the wide FoV (Filed of View) from larger eyepieces. Some of the best observing nights I’ve had is all down to this scope. See a previous post with more a detailed account.

Here’s what you get in the box: — Telescope OTA
-Telescope Mount
– StarPointer Finderscope (not needed if using a StarSense device)
– 2 x 1.25″ Plössl Eyepieces (basic eyepieces replace these asap)
– 1.25″ Star Diagonal (keep or change to a 2″ as desired)
– AC Adapter
– Hand Controller

So all in all, a very easy scope to set up and use, lightweight, but given the right conditions, some good eyepieces and nice dark skies this is powerful enough to give great views of many objects in the sky. If you’re thinking of buying one of these go ahead, you won’t regret it.

Coming in Part 2 of the series…..A review of a William Optics Zenithstar 73 APO

China well placed for a new decade of space exploration

© 2019 CNSA

While China’s space exploration goes back decades to the late 1960’s when the first tangible efforts begun with the development of Shuguang-1It was designed to carry a crew of two, not too dissimilar to the US Gemini capsule of the early to mid-1960’s. Although it launched its first satellite into orbit in 1970, sadly, China was not destined to launch humans into orbit until over three decades later. 

Shuguang-1 Spacecraft with crew capsule

Image credit: © Mark Wade http://www.astronautix.com/

In October 2003, Project 921 (The Shenzhou program) reached its zenith with a first Chinese crewed mission. Subsequent launches in the program saw China’s fist spacewalk mission and crewed test missions for China’s future space station as part of the multi-phase Tiangong program. With the goal of establishing a permanent human presence in space just like that of the International Space Station. 

Below, is what the future Chinese space station is expected to look like. 

A satellite in space

Description automatically generated
Image credit: © CMSA

China is indeed making huge strides forward, a lunar rover in 2014 and a second in the same program in 2019 and with the successful launch of its Long March 5 rocket on 27/12/19 capable of delivering a 25 ton payload, China’s future plans for a a lunar base and a Mars mission look well on their way. Watch the Long March 5 launch video here.

China has a reported $8bn budget set aside for its space program, I say double it, cut the military spending by 5% and accelerate human exploration of space. In fact an even better idea might be to cut the global defence spending by 5% and have an estimated $95bn for all space agencies to jointly collaborate on a human mission to Mars to be achieved by 2030. Now there’s a thought. 

Astronomers great woe of 2019

Image credit: Image: © 2016 Synertone Communication Corporation

While many people in the astronomy community have been up in arms in 2019 regarding the planned expansion of communication satellite constellations, others are taking a ‘wait and see’ approach to the intentions of various corporations on placing tens of thousands of these in various orbital altitudes. 

Besides the issues and concerns people have, companies like SpaceX and OneWeb promise huge benefits such as providing fast internet to remote areas as well as to airplanes and shipping. It is claimed that the network will be as much as 50% faster than fibre optic delivery of internet, supported by the fact that light moves through space much faster than through what is essentially glass. Outside of main urban centres around the world, it is quite common for people to still have issues with accessing reliable high-speed internet, these constellations could change all of that. 

Below is a video posted on YouTube of 60 Starlink satellites orbiting over the Netherlands shortly after launch on 24/05/2019. Notice the time stamp on the video (22:55 24/05/19) On that date sunset was 21:42 in Amsterdam (I Picked Amsterdam as referent point, The Netherlands is a pretty small country so not much difference in sunset time).

Credit: Dr. Marco Langbroek (sattrackcam.blogspot.com) YouTube link: https://www.youtube.com/watch?v=ytUygPqjXEc

Another video posted on YouTube in December 2019 shows a guy in the Brecon Beacons South Wales shooting the sky with a clickbait title: Astronomy is Doomed! Come on man!, astronomy is not doomed. Also if you watch the video you can see in the background plenty of planes taking off and landing, these have lights, flashing ones!!! Also again, he’s out between 5 and 6 am, a couple of hours before sunrise, if he went out at 1am, would he even see them? The video can be found here: https://www.youtube.com/watch?v=hfUmeCBvIQ0&feature=youtu.be Maybe it is a big issue for some people, but I personally do not believe that astronomy is doomed.

These corporations have a responsibility to ensure space debris does not increase as a result of these plans, although it most likely will. The impacts on science could be significant with the IAU (International Astronomical Union) voicing their concerns, see here for more.

As for the impacts on me, there hasn’t really been any so far. I rarely go out at dusk or dawn with the scopes which is when the light from the Sun will be most reflective on satellites, usually it’s several hours after sunset between the months of September and April. Also, imaging makes up less than 10% of my activities, so a very low impact there too.

One thing’s for sure this is not going to go away, we will need to find new innovative ways to adapt and no doubt we will. 

Arcturus Light 1982 AD

23/12/19

An approximate comparison of our Sun to Arcturus. (atribution: Windows to the Universe and/or http://www.windows.ucar.edu/ [Attribution], via Wikimedia Commons)

What did you see when I was 9 years old? Was it the end of unspeakable atrocities, Or just the continuation of more of the same. Were you curious of humanity’s first winged adventure, the reunification of a fatherland, or the precursor of a blight that forged the future?

In 2019 the light seen from Arcturus had been travelling since 1982AD. It lies approximately 36.7 light years away in the constellation Boötes. There are connections to be found in everyone and everything we see around us, connections to the past can even be made by what we see in the night sky.

Even a distant Galaxy can stir the imagination in many unexpected ways. Photons connect us to an era long before dinosaurs became extinct via M58, a spiral galaxy 62mly away. The 124 million year round trip facilitated by a technologically adept species inhabiting a system in the outer arms of the galaxy, their use of an an advanced optical instrument gathering the light and sending it back towards our system in the hope that at some point in their distant future, something here would ‘see’ it. And then us, human as we are, continue to develop, to invent, to see over the next hill until when one day, we learn to regenerate degraded photons, extract the data and have a high definition window on the past as it happened. A bit far fetched I know, but is it really THAT unthinkable?

Naming Exoplanets.

22/12/19

A wonderful initiative by the IAU recently called nameexoworlds, facilitated the naming of exoplanets and their stars by various countries across the globe. A great way to promote and spread the knowledge of our discoveries to date and the vastness of what is yet to be discovered.

Always a subject to raise the hairs on the back of my neck. Exoplanets always seem to me like the unexplored far away lands lands and oceans of our ancestors, if the imagination is set free endless possibilities are born. From our earliest ancestors leaving the African continent to the Pacific Islanders who took thousands of years to inhabit the vast ocean, the great sea voyages by European Empires in what must have seemed like one exotic discovery after another. People like Shackleton, Crean and Scott exploring the great Antarctic to humanity’s first flights into space and humans setting foot on the moon. The very desire to explore is the essence of our species, inventing new ways to discover has been one of the drivers of our survival.

Discover the work undertaken by the IAU and see what contribution was made by your country here: http://www.nameexoworlds.iau.org/final-results. You can download a pdf or excel file of the catalogue.

See below an image of the star system HAT-P-36 with it’s one known orbiting planet HAT-P-36 -b. The system lies within the constellation Canes Venatici (hunting dogs) and is approx. 6.6bn years old. The star itself is 1.10 times the radius of our sun. The star and the planet were named Tuiren and Bran respectively from the Irish mythological story about Tuiren who was the aunt of a hunter-warrior named Fionn Mac Cumhaill. She was turned into a hound by the jealous fairy Uchtdealbh. Later, Tuiren had a son called Bran.

Learn more about exoplanets by visiting the NASA exoplanet website here: https://exoplanets.nasa.gov

If you’re interested in learning about Tuiren and Bran, try here: http://www.luminarium.org/mythology/ireland/birthofbran.htm

Featured image (header) is under a Creative Chttps://commons.wikimedia.org/wiki/File:An_exoplanet_seen_from_its_moon_(artist%27s_impression).jpg

Sensationalist Press to be destroyed by killer asteroid.

17/08/19

Just as I was carrying out a search for some sizeable asteroids coming within viewing distance over the next few years I noticed lots of click bait on google about ‘killer asteroids heading our way’, some of the articles quoting scientists out of context coupled with units of measurement most people would not understand would lead many people to believe that mass extinctions by asteroids will commence in the year 2027 with a series of hits from space rocks. How about we gather all the sensationalist press, squeeze them all into a tin can and send them on a deadly collision course with one of these asteroids. Check some out here: https://www.space.com/six-asteroids-will-buzz-earth-late-2020s.html

Image header used under Creative Commons license. Link to file location: https://commons.wikimedia.org/wiki/File:The_Yellow_Press_by_L.M._Glackens.jpg

M13 – The Hercules Cluster

image credit: NASA

This is a beast of a DSO, at least I think so. Before I give an overview of this object (these objects), spare a thought to our one and only star, The Sun, our lonely parent star carrying out its duty in the great cosmos, giving life to everything we know of on Earth, sustaining all of the of the planets and holding millions of other solar system objects such as dwarf planets, asteroids and comets rotating in an apparently infinite dance. Now, imagine The Hercules Cluster It contains approx. 300,000 stars (M13), and has a spherical diameter of 145 light years. To put this into some kind of imaginable perspective, it will take the Voyager spacecraft approximately 70,000 years to to reach the closest known star to us which is Proxima B, about 4.42 light years away.  The Hercules Cluster was first discovered by Edmond Halley in 1714 ( as far as we know) , (yes that’s the guy, Halley’s Comet) and was catalogued by Charles Messier in 1764 and given the designation M 13 (Messier 13).   It’s currently just over 22000 light years from Earth. It’s a fantastic deep sky object to view in summer months and beyond. Imagine what it must be like standing on a planet orbiting a star in this cluster, the night sky must be amazing. Check out below where I’ve post a screen shot showing the location of M13 around this time of year ( Midnight, May 25th), current location is the south coast of Ireland.

My God, it’s full of DSOs.

Just back from one of the best nights observing I’ve ever experienced. First of all, I’ve had some great night’s before where I would observe many DSOs, but this was just awesome, more than 100 objects with several sharing the same field of view within the eyepiece. What was even more pleasing was that I was using the 6″ SCT in the remote location with a variety of eyepieces, is it was really being pushed to the limit but never disappointed. I must also add that the seeing was particularly good tonight in this dark sky location.

I arrived early and with my initial set up complete all I had to do was wait. 

Once night replaced day I was able to get going, with the StarSense AutoAlign I had the scope set up quickly. My current dark site scope is the Celestron NexStar Evolution 6, granted it doesn’t gather as many photons as the EDGE 11, but it’s a nice and handy grab and go option and with the increasing amount of light pollution where my home observatory is situated. I find myself more often starting up the engine for a night of astronomy rather than rolling off the roof. 

After a brief freak out when a stray cable got snagged as the scope was slewing and messed the alignment up, I quickly resolved the issue and re-aligned and hit my first object; Mars. Still visible in the western sky albeit quite low and at a current distance of 2.26 au (339 million km), it’s light right now (May 4th 2019) takes 18.84 light mins to reach us. Once my mind was set at ease and I knew I hadn’t mucked up the motors in the mount I savoured the thought of exploring the Virgo Cluster of galaxies and what a treat was in store for my eyes. Now, I knew that I would be pushing the small mobile scope to the limit as many of the DSOs I was going after would be very faint fuzziies, and coupled with my  current favourite eyepiece, an Explore Scientific 30mm argon purged 82° beauty, I dove right in and sent the scope pointing straight to Messier 87, approx. 55 mly away,  the source of the very recent and by now famous first image of a black hole.

The galaxy itself appears like a ball of fuzz such as the one seen below, but  when those photons left on their journey to Earth, only 10 million years had passed since the last great extinction event took place here triggered by the infamous Yukutan Peninsula asteroid strike.

M87. Image source: dailygalaxy.com https://dailygalaxy.com/2015/10/image-of-the-day-the-colossal-black-hole-at-center-of-galaxy-m87-will-it-be-1st-ever-seen/

Outside of Virgo I slewed over to Ursa Major to M81 (Bode’s Nebula) and the Cigar Galaxy, all in one nice field of view. Always a favourite of mine, but this was my first time seeing both at the same time. Back to Virgo and to Markarian’s Chain, a nice line of galaxies in the northern part of the cluster, I managed several of these and three in the same filed of view. Too many other objects to speak of including the Blackeye and Sombrero Galaxies, some nebulae including the Blinking Planetary Nebula, the Ring Nebula and the Eskimo Nebula and 5 star clusters. 

It started to get pretty chilly but I was more than satisfied with the results. The next time I anticipate similar conditions I’ll be bringing the full force of my arsenal with me and really hope to have a real go at some proper DSO astro imaging with a wide field refractor and a nice little camera from ZWO. More on that in a future post.

Here’s a list of gear I had with me tonight:

Celestron NexStar Evolution 6

Explore Scientific 2″ 82° Ar purged 30mm eyepiece

Baader Planetarium 1.25″ 8-24mm Hyperion Zoom eyepiece 

Celestron StarSense AutoAlign

iPad mini 4 running Sky Portal