A New Toy - and First Light!

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A New Toy - and First Light!

Post by cloud_cover »

Finally after almost 3 months I have a chance to put the new toy through its paces! For first light, Gary and myself decided to run up to Sedili to see what the new scope, a 14" f/4.7 Dobsonian with a Mark Cowan mirror could do in relatively darker skies. As usual, the weather was co-operative
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But first, a sumptous dinner in JB to take advantage of the cheaper Ringgit :)
(Note: Dish with green flag was Gary's, not mine! Reverse side of the toothpick-flag says "Not So Brave!" :mrgreen: Nando's fans, you'll know what I mean)
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On to Sedili and thankfully by then the skies had cleared to intermittent passing clouds. A nightmare for imagers but no issue for visual observers! Sadly, Servocat chose this time to malfunction so for the night we were forced to put the scope through its paces manually. This turned out to be a good thing because it gave me increased confidence in my scope and its manual use. Besides, I had the guru of visuals, Gary, present to be my goto unit!

After a quick setup and collimation (its really much faster than setting up any tripod based mount!), we were good to go and Pleiades was the first target! Using a 31mm eyepiece we were only able to get part of the large cluster in view but Gary could see some faint nebulosity surrounds the main stars. On my part I though it might be background haze or glare from the stars but I'm not sure.

Then on to Jupiter! The king of the planets. Jupiter is a very discriminating target because it has both high and low contrast features. In a telescope, optical quality is often determined by the contrast produced by the telescope, much less so than the sheer brightness afforded by the aperture. It was a lovely sight at 51x in the 31mm but on switching to an 8mm eyepiece at 200x, the detail was breathtaking! I was too busy admiring the swirls in the Great Red Spot and the 3 white ovals nearby to count the bands. All this when Jupiter was already setting hence in less optimal observing position was truly impressive!

However, we didn't drive all the way there just to look at planets! Planets can be seen just as well from Singapore. On to that famous Great Nebula in Orion. The Orion Nebula is easily visible back in bright Singapore through 50mm binos and even the naked eye on good nights although its more often seen as a patch of brightness in the approximate fan or bat shape. Through the 31mm the detail seen in the cloud was truly breathtaking. To call it "nebulosity" simply does not convey the depth of detail visible. The 2 main arms were visible as thick tubes extending outward where they fan out and eventually join (yes, the WHOLE nebula was visible, including the much dimmer outer areas, to direct vision) The centre where the Trapezium lies almost looked like it was in a bowl formed by the 2 arms, with much ripples or waves easily seen. At this power one can only make out 4 trapezium stars. Faced with this display, we didn't bother with the UHC filter. To see if we could split the Trapezium, we changed back to the 8mm giving 200x. Now the E and F stars of the trapezium were clearly visible to casual direct observation. No need for squinting, concentrating or averted vision. The texture of the nebula through the view was truly awesome. I felt as if I was in a spacecraft looking up into the vast stellar cloud!

Encouraged to move on (ahem!), we cycled through a variety of open clusters. Here the 14" did not perform as amazingly as it did previously, mainly because in a dark sky a fair amount of open clusters are well visualized in smaller telescopes and large enough that the True Field of View (TFOV) of my widest eyepiece (1.8°) did not frame the cluster fully in its surroundings. Here I actually preferred, for some, the view through a 4" refractor. Of course we were only looking at Messier catalogued clusters, which are among the brightest in the sky. If we had turned the scope to much dimmer clusters then the much smaller aperture of the 4" would have been woefully inadequate. Among the open clusters though, one special one deserves mention: M35 in Gemini is a beautiful cluster spanning about 2/3 of a degree but when lookign at it in the big scope, there was a wisp of "nebulosity" at one side, almost as if God took a cotton ball to clean the cluster then left it there! In closer inspection the "nebulosity" appeared granular so again in went the 8mm eyepiece which afforded a well resolved view of the globular cluster NGC2168. It was a beautiful sight of shimmering points on a dark sky with the adjacent bright stars of the cluster. I most appreciated this view most in the 13mm which, at 0.8deg TFOV gave the best balance between field of view and power to resolve NGC2168

We then moved on to galaxy hunting! Traditionally the forte of larger scopes, the 14" put in a good performance. All 3 of the Leo triplets were clearly and evidently visible to casual direct vision. The dark band across NGC3628 was visible to me with direct vision when concentrating on it. It was, however easily noticed in averted vision. Moving on to the Whirlpool in Canes Venaticti (or more easily, just at the end of the handle in the Big Dipper), the dual cores with surrounding brightness was seen. Very nice! Unfortunately our skies were (for a dark site) moderately bright due to some new chalets with naked bright bulbs built just adjacent to the observation area as well as the high moisture in the sky from the recently passed rainstorm so some of the outer features of the galaxies simply blended into the not-quite-black skies.

By this time the Eta Carina area had risen into view. Here lots of open clusters come into view, including the very large Southern Pleiades and X Car cluster (NGC3532). Again I much preferred the larger FOV of the refractor although this region is so star rich that the smaller FOV of the 14" didn't seem so important. Still, at 1.6° wide, even the 31mm could not well frame the Southern Pleiades. Much better framed were the Jewel Box cluster and NGC3532. Gary saw lots of beautiful color in the Jewel Box.
On to the true gem of Carina, the Eta Carina Nebula (NGC3372)! At first glance it was somewhat disappointing: A bright streak of light like a brush stroke splashed out amongst a tapestry of glittering diamonds. this confused me for a while as I have seen the Eta C nebula through Binos and my trusty 4" refractor and one can make out its flower-shape, vaguely, with that bright streak being the brightest petal. Thoughts flashed through my mind: How large scopes don't really brighten extended objects, such as nebulae: they just magnify them. Truthfully, I was quite disappointed at this time. Why nothing more than a splash of light? After the awe inspiring spectacle that was the Orion nebula! Checking back with Skysafari, I noticed one small detail: The whole Eta Carina Nebula spanned more than 2 degrees across! Now it dawned on me: I wasn't seeing more nebulosity because the entire eyepiece was ALL nebula! Unfortunately our skies were not so dark that the dark lanes between the lobes of the nebula were evident. In goes the UHC filter and suddenly I'm staring down the dark lanes separating the lobes of the nebula. Texture and filaments of dark dust lanes interspersed by the all-pervading glow of nebula light filled the whole eyepiece making this again an wonderful spectacle. through my silly grin I unfortunately forgot to hunt out the Homunculus, that mass of ejecta from the last brightening of the Eta Carina star itself. Its mind boggling to think that about 10 years after Singapore was founded by Sir Stamford Raffles, Eta Carina was the second brightest star in the sky, losing only to Sirius! How our ancestors must have gazed at that "new" star in the darkness that was then the Kampung of Singapura, the port-island south of Malaya.

On to Omega Centauri, that pre-eminent of Globulars. To say jaw-dropping was an understatement as the cluster was fully resolved down to its core. previously I've never paid much attention to observing Omega C because its often just a hazy blob with some surrounding granularity in both my 4" refractor and 8" MCT. With the 14" though it was a large ball of twinkling diamonds with almost no core and I could almost imagine irregular, twisty dark lanes coursing through the near-centre, like secret extra-galactic country lanes going down tree-filled hollows. Gary best enjoyed the view at 76x in the 21mm although I found that to still be too small for my liking. I enjoyed it best in the 8" where it filled up two-thirds of the FOV. I could just stare at it for hours...

By now it was getting late and what with family commitments, Gary was reminding me its time to pack up (Thanks Gary for helping me ensure my "higher authority" will allow future trips!) Still, a short pause to view that most mesmerizing of planets, Saturn. By now it had just risen above the treetops. While not in optimal position (Planets suffer greatly from atmospheric effects because of their small-sized features so the best position for planetary viewing is really near-zenith), through the 31mm Saturn was nicely seen as a miniature caricature of itself, with rings well defined. Pop in the 8mm and suddenly here's a much larger planet with the Cassini division in the rings clearly visible and bands on the planet itself. Sadly, the absence of Servocat made it difficult to keep the planet from drifting as I popped in the next eyepiece, a 3.7mm for 432x, but the view was again, fantastic. (I'm trying not to let my jaw drop too much. Dentists are so expensive and hard to make appointments with!) Not only was the Cassini divison a chasm diving the rings, but I could easily see the "texture" in the rings, thickest just inside of Cassini and thinner on the inner and outer rims of the rings. I think I could faintly see the Encke Divison as well. The globe of the planet was a series of grey-yellow bands in upper hemisphere and golden-yellow in the lower that was not covered by the rings.

After a brief period more of admiring the planet together, Gary, ever mindful of my welfare reminded me of the time again and reluctantly we packed up and headed home.

Me looking fat and looking into the eyepiece at the same time
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The scope :)
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Gary
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Re: A New Toy - and First Light!

Post by Gary »

A fun and detail visual report from an APer! Good job! [smilie=good-job.gif]

Finally the NDA has been lifted! :) Almost 3 months? Felt like yesterday when we had a very interesting experience bringing in the toy from Singapore customs. :)

Just adding a few more points here so I can recall them easier if I have time to blog about it someday:

- Firstly, big thanks to Rlow for inviting me to experience a big premium dob under a dark sky for the first time in my life in Sedili last year. Though that night overall was not very clear, there were clear patches at the thickest part of the Summer Milky Way. The view of the M22 looking really like a cluster of stars (and not a fuzzy cotton ball ) is still stuck in my mind. Stage was set to see the greatest globular cluster through a big dob someday!

Pity the weather that night wasn't clear for a long period, else it would have even been more amazing to see more of the real visual guru and human GOTO at work!

Thanks to cloud cover, I finally had my big-dob-under-clear-dark-sky "revenge".

- Coming back to Sedili trip on Wednesday, I wasn't too concern about the tracking and electronic gizmos. That's why before we left Singapore, I only asked if the dob can be operated manually in the event of an electronic malfunction - so prophetic in hindsight! :)

- Upon reaching ground zero, quickly got out of the car and looked up. WAAAAAAAAA~~~! Makes me feel like reliving my first Johor stargazing trip in Segamat all over again! Winter Milky Way already visible with naked non-dark-adapted-yet eyes. Adrenaline rush to the max.

- Spent some time observing with cloud cover's excellent Nikon binocular while waiting for the dob to setup. Collinder 70 (open cluster including Orion's belt) was just as spectacular as I remembered it back in Johor last year - stars, stars and stars everywhere in the wide field of view! Followed by M35, M36, M37, M38, M41, Hyades, Pleiades, ...etc.

- When the dob was ready for action, Orion was the first object we saw, not Pleiades. Plopped in a 31mm Nagler, let the dob owner have the honor of first-lighting the first object in a dark sky and then it was my turn.

*#$%&#$^!!! Can't remember the exact expletives I yelled out when I saw this truly Great Nebula. It's like seeing fluffy clouds in the sky except this time it is nebulosity through an eyepiece!

To give an idea how amazingly bright the views were, this is a photo of stars in M42 ... ... taken with my handheld *mobile phone*!!!

Image

- After Orion Nebula, forgotten the chronological order of the objects I saw. Since we can't stay too late, it is important to not to spend too much time on the first few objects. Weather being unpredictable, you never know how the night will turn out. Fortunately, overall it was very fruitful. There were some brief cloudy moments but even in such moments, some clear patches can be found and we just observe the goodies there. Ah, the pleasures of visual astronomy to maximise every second under a clear sky . :)

Of course such a strategy means we may overlook some goodies or try more eyepiece combo or filters on a certain object but I still think it is worth the tradeoff, e.g. wanting to observe Carina goodies just to realised it was blocked by another treetop by then.

- NGC2362 near hind legs of Canis Major - I "discovered" it in segamat with my C8. Back then, the triangular bunch of stars can be seen obviously with a very slight averted vision (AV). Had fun going direct vision and av back and forth quickly to see the triangular cluster appearing and disappearing. Observed this with Starfinder at the same location on a different night.

Dob view at Sedili - The triangular bunch of stars stares right at you! What AV? With AV, it gets even brighter and the nebulosity more obvious. This object is truly one of the most underrated gems of the night sky.

- Objects at Carina - brighter stars with more nebulosity than last seen in my C8 and 5" achromat. UHC on Carina Nebula - amazing nebulosity and dark lanes but personally, at the expense of seeing slightly greenish looking stars and thus destroying the illusion of space-walking for me.

- Eskimo Nebula - seeing it visually for the first time in a dob. So amazingly thick and obvious as we bumped up the magnfication. Who left a parka hood in Space? :)

- Omega Centauri - or the OC, as cloud cover affectionately calls it. The very moment it popped out of view beyond the last leaf of the treetop, we aimed the cannon at it. Hail to the King of GC! Hercules please go stand one corner. :) Fantastically resolved bunched of stars most aesthetically framed in the 21mm Nagler to me. If you can only see one globular cluster through a big dob in your lifetime, the OC let it be!

- Happy to felt lost for a while trying to find Leo - too many stars!

- Galaxies M95 M96 - so obvious, so easy to spot and identify.

- M51 Whirlpool Galaxy - a pity it was still quite low and sky wasn't really clear at that patch. But still, bright cores so easily seen.

- Leo Triplet - Best view evaaaar. Seeing NGC 3628 for the first time. What a thrill to see the central dark lane across it. Even more obvious with AV.

- Saturn - Amazing details despite relatively low attitude. Brings back fond memories of Saturn through Rlow's big dob during a Saturn observation session outside Toa Payoh Public Library.

- Jupiter - Great Red Spot so obvious and can see the pinkish "flesh" within the oval. About to set and not at optimal viewing altitude.

- Castor - Clean split at low magnification. Chicken feed for the dob.

- So many objects we should have attempted but we can't stay too long - e.g. Centaurus A, more galaxies at Virgo, more double stars. But still, not much to complain about as a first light under dark sky, this is already way beyond my expectation in terms of views and sky conditions in mid-March.

- The 4" apo deployed is a premium refractor which cost about the same as this big dob. After a few comparisons, it was left alone in the dark as we continue to marvel at the dobsonian views. The Giro mount which the refractor was mounted on was smooth and feels very solid.

- This big dob (can we give it a name already? how about Cantonment? :P) was very smooth to push around. Makes you feel like you are pushing a small beginner's dob sweeping the sky almost effortlessly. Focusing was very smooth too - no need to guess if you have achieved the perfect focus through a particular eyepiece.

- Like Rlow's and Astrosiao's, very impressed with the quick setup-to-observing time of the dob. Drift align whaaaaat? :P

- Nothing dew up. Zero mossie and sandfly bites on my body.

- Open secret by now my astro idol is John Dobson. Thanks to Rlow's and Cloud Cover's big dob invitations to Sedili and Astrosiao's dob sessions at Toa Payoh, I had my little but my nonetheless very privileged glimpses of how it must have felt to observe and do outreach astronomy with a big dob at Yosemite National Park. The brilliance of the dobsonian design shall live forever!

- This is a very timely spark to rekindle my astro and sidewalk passion as my honeymoon period with visual astronomy seems to come to an end.

- The very-brave kampung half-chicken treat is probably my most value-for-money astronomical buy to date! :P

[space reserved for upcoming youtube video]
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It is how many people, less fortunate than you, got to look through it."
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maguro77
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Re: A New Toy - and First Light!

Post by maguro77 »

Hi guys, thanks for your very eloquent and detailed description of the amazing views through your new Dob. It has gotten me to dig out my small dob and want to start visual again. No cables, batteries, drift alignment, ISO, DSS stacking - back to simplicity.
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Re: A New Toy - and First Light!

Post by depardeuz »

The power of the dobsonians!!! :twisted:
Seize the day!
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Re: A New Toy - and First Light!

Post by weixing »

Hi,
Congratulation on your 14" and first light... [smilie=admire.gif]

Anyway, I thought Jupiter should be the last object to see in dark sky country... it's a "light pollution" and will ruin your night adaption... ha ha ha :mrgreen:

Have a nice day.
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Re: A New Toy - and First Light!

Post by rcj »

it was enjoyable reading your report of the visual experience from Sedili, Kevin. We happened to be in Sedili on Sunday exploring the area, which part of Sedili did you observe from? Must get a big dob soon.
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Re: A New Toy - and First Light!

Post by starfinder »

A very good report, Kevin! And very good supplement too from Gary!

Your descriptions prove once again the maxim that, generally speaking, aperture wins.

However, my experience also is that the improvement in view of an object as aperture increases varies from one object to another. For example, I've seen Omega Centauri at dark sky sites through a variety of apertures from 3-5 in, 8 in, 12.5, 15 in, 18 in and even 25 in; I recall that there's a huge improvement between 8 and 12.5 (eg Canopus' 12.5 in Dob at Kahang and Chee Chien's 12.5 in Dob in Mersing I think), but it's so bright and detailed at that level that beyond that it does not seem so much more improved (perhaps I needed to study it carefully).

On the other hand, with fainter and more diffuse objects like galaxies, I think it's a case of the more the merrier by a lot. E.g., the view of Centaurus A through a 25 in giant Dob in Australia was really unforgettable. I recall that it was so bright and well defined, like some hamburger in space. And likewise for planetary and emission nebulae too. I recall that the view of the Ring Nebula M57 through the NUS 17 in Planewave scope at Kent Ridge was quite surreal.

Having said all that, for general star fields, lower apertures are I think better because of the wider fields of view, and here the refractor and binocular are king due to their high contrast and twinkling stars we can see. Views of the Puppis, Auriga and Cygnus star fields, and the Sagittarius Milky Way are simply awesome from a dark sky site with a 100mm (4 in) bino, or even a 15x50 bino will afford superb views. A general sweep with a 80mm scope too can be excellent, and I just did some very enjoyable viewing of star fields with my 120mm Skywatcher ED refractor (Kochu's ex scope) at Mersing on Sat night: the sight of countless thousands of tiny pin-point stars was sublime. And I recall years ago viewing the heart of the Milky Way region through a 100mm bino at 25x in Mersing (Telok Sari): I saw 3D-like curtains of light and dark that was simply mesmerising (I wrote about it then on this forum).

So here my message to other astronomers once again is: don't overlook general star fields and clouds (such as those in the constellations I mentioned above) that don't have a Messier or other catalog number: the views here often exceed almost all other individual DSOs and you'll be missing a lot if you don't spend time with them.
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Re: A New Toy - and First Light!

Post by starfinder »

Hey Kevin, would you be 'demo-ing' your new scope in Sg soon? You're making us suffer from aperture fever!

Anyone else interested?
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Re: A New Toy - and First Light!

Post by Airconvent »

Hi Gary
If you had joined rlow, you would have stopped at his favourite restaurant enroute to the site. We were there briefly for a toilet break so we could have met!
Always nice to check out a large aperture scope...so glad you enjoyed your first outing too. :)
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Re: A New Toy - and First Light!

Post by cloud_cover »

Thanks for all the encouragements!
It was a fun night and I only wished we had more time and the tracking was working. Sigh!
Yes, I'd like to bring out my scope locally but currently swamped with work! Still, it'll be a blast to do planetary nebulae in Singapore :)
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