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A small refractor looks at Mars

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#1 Meep_Esq

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Posted 29 January 2014 - 05:01 PM

For once the 4am alarm co-coincided with good seeing and I was rewarded with reasonably crisp views of the Red Planet. It's still fairly small, but I was able to use a 6mm plossl to get 250x with steady results. The gibbous phase was easily seen and the Nth polar cap evident along with a nice contrast effect at the margins of the cap. Mars was too small to make out any definite detail, but there was an impression of mottling on the disc - alas the seeing was starting to waver as dawn approached, so it was most likely an artifact.

I also (re)learned that good seeing and patience will pay off more than you realise.

Looking forward to a few more early starts... :-)

#2 nirvanix

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Posted 29 January 2014 - 05:10 PM

Nice work Vaughn. Did you get any impressions of the South Polar Hood? 250x mag for a 4" refractor is great. Is it one of those Antares long achros?

#3 Meep_Esq

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Posted 29 January 2014 - 06:04 PM

Re: polar hood - Not that I could tell. I've never tried observing Mars this early in the opposition before, so I'm not sure what I can see! :) Plus, for me it's our summer, and the prevailing northerly weather usually brings disturbed seeing, so I was quite lucky :-) I've done early morning vigils before now, and I'd say the results are usually worth the disturbed slumber :-)

My telescope is homebuilt from a 1980's-era Edmund Scientific objective. So it's a 100mm (almost 4 inches!) f/15. I dont think anyone sold short focus refractors much back then. They still provide (source? make?) objectives: Edmund Scientific They seem pricey now, compared to what you can get from places like Istar or D&G.

#4 kdenny2

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Posted 29 January 2014 - 07:20 PM

FWIW, in my 8" reflector I was able to make out very subtle contrasts on Mars' disk near the poles. It'll be exciting to see what it'll look like at opposition.

#5 Ed D

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Posted 29 January 2014 - 11:05 PM

Good observation with your 100mm. I'm up early in the mornings and prefer to observe while having my coffee. What I have noticed is that, given mornings of equally good conditions, some mornings I can observe more features while other mornings the planet seems to be more lack-luster. Hope you get more early morning opportunities and can catch more detail.

Ed D

#6 Meep_Esq

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Posted 30 January 2014 - 08:16 PM

Hi Ed

Evenings used to be my main time for observing, but of course, it could easily be midnight before the seeing has settled (And I'm a man who loves his sleep). Summer seeing seems worse than winter where I live, and mornings seem better than evenings, so I now aim to observe in the early hours as much as I can.

This mornings session was a bit of a washout. Seeing was about 2 on the Antoniadii scale (yesterday was a 1, and I really wish I'd taken the time to make a sketch! Never mind! Hope your skies improve!

#7 Meep_Esq

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Posted 30 January 2014 - 08:23 PM

Hi Kdenny.

I'm looking forward to revamping my collection of filters - even on a wee scope they're useful enough to pull out the details. I'm also working on an 8" Newt, but who knows when that's going to be finished!

Clear skies...

#8 Illinois

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Posted 31 January 2014 - 07:52 AM

That's good details for your telescope. 2 weeks before and after around April 15th should be good!

#9 Meep_Esq

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Posted 09 February 2014 - 12:06 PM

Well I've been cursed with the most peculiar skies lately - the stars are out but the seeing has been rotten! Airy discs look like meatballs. USually the game is about the nudging and waiting for Mars to sail across the fov. When it's like this, finding focus is more of a challenge! Of course, no details of any kind could be seen. Mars remained and inscrutable orange fuzzball that would constantly flair up into a hairy mess.

However, I did have a bit of fun, looking at the turbulence by aligning on a star, and removing the eyepiece. Usually you can see the turbulent cells of air as rapidly oscillating blotches. Occasionally I've seen what appear to be streams or currents of disturbance (especially when I am looking low and west, where a small valley is.) Tonight it seemed as though I was looking at a rippling sheet. A weirdly fascinating thing to see.

Never mind, there's a change in the weather due in a few days, maybe things will improve!

#10 Meep_Esq

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Posted 23 February 2014 - 01:27 PM

Well this morning's session was the most productive for a while. The weather, while clear, has been fuzzy and mushy. Yesterday we had a cold southerly which seems to have almost smoothed over the skies somehow.

Seeing was 2 - 1 on the Antoniadi scale. Mars is perceptibly bigger now. You can see the gibbous phase is less pronounced, but still there. The polar cap seems to have less contrast when compared the to rest of the disc. It seems only a smidge brighter than the disc itself. There is a suggestion of shading on the disc now, but it's very very faint and hard to tease out.

Which leads me on to the value of making a drawing, rather than scribbling lots of notes! There's no arguing with what you meant, or trying to interpret awful handwriting in your log!

Today, I could see, an unmistakable bright feature on the edge of the trailing limb at about the 8 o'clock position. A light blue filter improved the contrast between the disc and the feature. Further study with the filter, and blinking the filter lead me to believe that perhaps I was seeing a contrast effect due to a darker area on the disc itself and a gap in that dark area where the "feature" was:

Posted Image
I've just realised I've labelled the poles round the wrong was *doh* :-)

In my drawing the bright feature is at the bottom, with the vague darker area around it. The dotted line shows the general extent of it. I tried shading the drawing to give more of an impression as to what was there, but I forgot how gritty the scanner makes everything. The contrasts were very subtle, although the bright area seemed lighter than the polar cap.

So anyhoo, first drawing for me for the season. Looking forward to seeing more as opposition gets closer!

#11 kcb

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Posted 23 February 2014 - 08:37 PM

hi,
i was also out with my 4'' f/15 skylight refractor and even here in ontario canada the seeing is not the best in our winter, however in slight seconds i could discern a nice disc with hints of shadings and a polar cap,hopeful for better seeing around mid march,our spring,new zealand must be a neat place,kevin

#12 Meep_Esq

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Posted 24 February 2014 - 07:17 PM

hi,
i was also out with my 4'' f/15 skylight refractor and even here in ontario canada the seeing is not the best in our winter, however in slight seconds i could discern a nice disc with hints of shadings and a polar cap,hopeful for better seeing around mid march,our spring,new zealand must be a neat place,kevin


Hi Kevin. It's interesting as to what might cause good and bad seeing. Certainly where I live the seasons play a part, cooler weather (which tends to come in from the Southern Ocean) seems more likely to be steady. Warmer weather, which has generally passed overland and spills over the top of a mountain north of me, seems less settled. I hope your seeing improves, it certainly makes all the difference with smaller instruments I think.

Where I live is a small city on the coast. Half an hours drive and you're in the country which is nice - it's mostly farmland. Dunedin is like most places I guess, some of it's pretty, some of it not so much! :-) I guess the neat thing about NZ is that you can go from city to country, to mountains and rugged bush, all in a day! :-)

#13 azure1961p

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Posted 24 February 2014 - 07:48 PM

Vaughn,

Very nice reports. A 100mm at f/15 is nice classic set up that as you know can provide some terrific views. I'm glad you were able to get some steady seeing despite some poor as well. Ill bet your scope shows it all comes April.

Pete

#14 kcb

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Posted 25 February 2014 - 09:20 PM

hi vaughn,
thanks for reply,
i am just opposite than you at 44.5 degrees north ,i live on georgian bay in canada where many movie stars and rock stars have cottages up here in the 30,000 islands in muskoka,i am very near the worlds first dark sky reserve torrance barrens,i live in cottage country so i dont have to travel much as it is scenic here but i always had a soft spot for new zealand,someday i wish to see the southern sky,clear skies,kevin

#15 Meep_Esq

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Posted 23 March 2014 - 08:02 PM

Great view of Mars this morning. Seeing was about 1-2, but then degraded over the course of the hour. My 4 o'clock vigils might have to start earlier as Mars sinks too low in the sky and catches that muzzy horizon air by the time I finish :-)

The N.polar cap seems to be beyond my wee scope now. I thought this was the case from the 12th. There were moments where I thought I could glimpse something, but the seeing just simply wasn't perfect. I still think of all the things that make a difference to planetary observing, the seeing is the most important. In fact the disc was quite blank this morning

In the same vein, I thought there was a glimpse of a bright region on the preceding edge. Most likely an optical illusion, but it's amazing how you can convince yourself that you are seeing "something". Of course, the best thing to do is to record it and throw your observation out into the wild and see if anyone else can corroborate it :-)

I've attached my observation from the 12th. I was actually able to make a drawing. A faint band which I think is Mare Cimmerium just visible.

Posted Image

Clear skies everyone! :-)

#16 azure1961p

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Posted 23 March 2014 - 10:32 PM

Well the good news is there's more interesting faces of mars than what was presented to you . Still its a nice ob and I enjoyed your report.

Pete

#17 Meep_Esq

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Posted 05 April 2014 - 11:45 PM

This was an observation from a few days ago (2nd Apr). Possibly one of the best views of Mars I have ever had.

This time I set my alarm early and got up after 2am. The sky was completely steady, no twinkling stars, with a slight haze.

The seeing was easily a 1 on the Antoniadi scale, and boy did it make all the difference. I could see the tiny disc of the N.polar cap which has previously eluded me in more average seeing conditions.

This was also the first time that I didn't feel like I had to "wait" for detail to appear. It was just there:

Posted Image

Stretched across the lower face of Mars, was a clearly discernable hockey-stick shaped feature. The arm of the feature is Sinus Meridiani and Sinus Sabaeus. The upturned end of the "stick" is Syrtis Major. The elbow was fainter than the main body.

From the polar cap down to the 9 o'clock position a dark feature which is Mare Acidalium. The polar cap was surrounded by a light collar-region that blended into the top of M.Acidalium. The edge of the disc at 9 o'clock was also distinctly brighter, it seemed to me only slightly darker than the polecap. But more curiously, it seemed to have a definite pale yellow-white tint, which contrasted against the pale salmon colour of the disc. The southern edge of the disc also seemed to have this same pale yellow colour, but no other parts of the edge shared this trait:

Posted Image

So, the clouds have returned, but things are looking to pick up in the middle of the week. I can't wait! :-)

#18 Meep_Esq

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Posted 29 April 2014 - 04:53 PM

Well we've had a mixed bag weather wise in the land of hobbits >:-) Australia's east coast was battered by a tropical cyclone and the remnants drifted across the Tasman Sea and cast a damp, cold, soggy cloak over most of New Zealand. On the plus side, I went went inland to the high country and spent a few days at Lake Tekapo in the McKenzie Basin, home to Mount John Observatory. The place has a stark beauty and the darkest skies in New Zealand. The ST80 got a good workout :-)

Posted Image

Heading back home, and the weather has blown over on the coast here and finally a glimpse of Mars on the downhill run from opposition:

Posted Image

Although the seeing was ok, it seemed to lack the crispness. All the same I was surprised I could see detail. The subtle colours from my last observation were washed out to a uniform yellow. There were no bright areas along the rim (Which were clouds I guess)

The dominant feature extending from the polar cap (which was a tiny spot of white) is Mare Acidalium which in white light was more blob like. In good moments there was the perception of a slightly darker tint extending to the following edge. A light yellow filter seemed to define the edges better and Acidalium looked more elongated with a "hook" to the left than in white light. A red filter seemed to make the dark albedo regions more intense, but alas the image was getting pretty dim by then!

#19 azure1961p

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Posted 29 April 2014 - 06:55 PM

Vaughn very nice work and in the pointelist method no less! I'm glad good seeing visited you - the lesser seeing ob you e dee with is still great though.

Bravo.

Pete

#20 Ed D

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Posted 29 April 2014 - 09:05 PM

Vaughn, glad to see you are getting some good Mars observations.

Ed D

#21 Meep_Esq

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Posted 30 April 2014 - 11:02 PM

Vaughn very nice work and in the pointelist method no less! I'm glad good seeing visited you - the lesser seeing ob you e dee with is still great though.

Bravo.

Pete


Thank you Pete. I'm using a 67mm sized blank with a 0.25mm pen, but I might make the blanks bigger, to help the dots blend in more. I used to use pencil shading, but it was a bit problematic when it came to scanning and uploading. I've been experimenting with ink drawing for a wee while, and I think the secret is probably a larger scale as it's bold medium.

Actually, if you stand back from the screen a bit so Mars is more "eyepiece sized" then the dots work quite well :-)

#22 Meep_Esq

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Posted 30 April 2014 - 11:10 PM

Vaughn, glad to see you are getting some good Mars observations.

Ed D


Thank you Ed. Last opposition wasn't so flash what with it being a bit low from my usual observing spot, so I felt a bit blase about it. This time round has been much better and it's co-coincided with our autumn, so the nights get darker earlier and the weather starts to settle down (when it's not raining!) I'm hoping to get an early session in tonight provided those clouds thin out a bit! :-)






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