Forum Replies Created
-
Posts
-
Really nice to see this.
The comet is approx 30 degrees from the sun, so the background should display Rayleigh scattering induced polarisation of a few percent. From memory, the orientation in the first image looks roughly right given the suns position pretty much below the north horizon. The comet should have its own dust response – as the Zodiacal light does – and certainly appears to here. I’m a bit perplexed by the orientation of the background polarisation in the second image though. Was the amplitude the same?
Your amplitude measure, was that a Stokes parameter or the degree of total linear polarisation or similar?
I imagine perfect alignment of the 4 polariser images is essential to the values measured when the target has fast changes in brightness. I have always had greatest problems getting good results in parts of the image with steep gradients – subpixel registration is important (I found to my cost).
I assume you only used linear polarisers.
Thanks for the clarification(s) on why you seemed to object to the device. Nice to understand the rationale. I must admit I rather liked the idea of using the PHD slit option. Seemed quite sneaky but can see why a mirror system might work better.
As you say, it ideally needs someone impartial trying both and seeing what works best in practice.
I wondered if any internal reflections made it visible. But and x/y cordinate should be enough really.
If the Lodestar x2 is being used for guiding, would it be possible to display that guiding frame in semi real time? Would really need to ask Terry or Michael I imagine.
Would make sense – the Lodestar x2 isnt a bad imager (SX7 without the cooling). But would you see where the slit was?
My take on it was that its self contained and very suitable for those lucky well heeled souls who have scopes at remote dark locations and so want the whole lot easily controllable and adjustable via a GUI. Similarly for university observatories to train up the students.
Thinking about it, there must be a market out there at some of the ITelescope type sites for a few of these. Look how long we had to wait for a spectrum of the new nova in Reticulum.
I too would be curious to see how it performed, preferably via a review done by someone not too bought-in to existing technology/manufacturers. People do tend to become tribal and sometimes don’t want to hear that something else is good in case it reflects poorly on their own purchase choices. I imagine we can all think of instances…
Morning,
I’m not really understanding what you don’t like about the new system. Concave grating corrected for astigmatism, on board ref, onboard flat and onboard focusing/guiding. I don’t do spectra, but that would certainly seem to tick some boxes.
Yep, I am ignorant, but I’m not seeing a lot to dislike beyond the price – but then again I struggle to understand why so many salivate over high end 4″ refractors when the same money would buy a 14″ Newt.
I don’t imagine the BAA will be subsidising purchase of these like they did for the Shelyak systems a year or two back.
What am I missing? 🙂
Thanks for the headsup. Am watching it now.
Blue CCDs. Excellent. I can have a camera that matches my eyes! I don’t care what colour it is as long as it still does the business but some people like their kit to be pretty. At least its not red.
For me the comet is still naked eye and about 5-6 degrees long. It was a bit hazy last night so tougher to see by direct vision but still there: https://britastro.org/node/23435
No obvious sign of banding in the dust tail but when using Live View the coma was clearly green.
Its been a real treat to have some tolerable weather and a comet with two bright tails.
We should start to see some images from Aus in about 10 days time… Hope its stays bright for them.
Is it just me or is the blue ion tail becoming more prominent, or is it merely that the comet is higher in the sky now?
Attached is a stack from the night of 17/8th July. When the comet spent an hour just above a line of clouds on the northern horizon.
They want fame, notoriety and followers – that way lies a big ego boost and advertising revenue. You see quite a few, er, augmented, pictures these days. Some more subtle than this.
I’m only surprised its not the Zetans coming in off the shoulder of Orion at last. 🙂
Morning of the 6th there were tiny gaps in the cloud and drizzle.
Morning of the 7th a bank of cloud from N-NW with tiny gaps, but huge clear bits overhead. Stood and hoped for an hour but didnt see it with binoculars nor on the SLR. 🙂
Perhaps tomorrow.
Despite that, the stillness of the predawn was wonderful.
EDIT: Eventually saw it evening of 10th. Worth the wait. Alas I fell asleep in a chair waiting for it to clear some trees for the 2am observation.
AstroArt7 does too – but obviously you would need a paid upgrade. Though AA7 is impressive and, most importantly, has a nice scripting language which is useful.
I have a Baader Oxygen filter which seemed to leak. I gave up using it because of it.
There may have been a faulty batch at some point.
As far as I understand it, about 10 mins after launch the second stage separates from the dragon capsule. Presumably, it then lags behind steadily as drag and the capsule thrusters start to do their thing. So, by the time they pass over us it would be quite a big separation. Anyone any ideas how big?
I’m wondering what lens to use to get both. As I’m only using a tripod, I’m assuming something like a 85-135mm with a short exposure and high ISO to avoid tralling.
This is going to be fun. 🙂
PS I believe that on this variant of the system the solar panels are actually fix mounted on the vehicle and do not deploy.
That looks like a rather nice way to spend some time this evening.
Now we just need good weather here and at Canaveral. 🙂
I’m with Callum on this, buy a cheap 32 bit used laptop for £60 and use that to run the camera only?
Have you established why the adaptors do not work?
Daniel Parrott, the US developer of Tycho Tracker, has just released another version of Tycho Tracker. As before, the best way of using it is via GPU – the good news is that it now lets you test the GPU you have installed and tells you if its compatible. If its not the right sort (or capable enough) the CPU option is still there.
A friend had trouble using the GPU version under a Linux Windows emulator (wine?) but now theres a CPU version that problem may not apply. I tried it on 22x 4min Starlight H18 frames of the ecliptic taken with an 11″ RASA and it found 5 asteroids on the frame (and identified them) and in addition a single unknown object down at mag 19 – that looked real to me. It wasnt quick (5.5hrs) but I set Tycho running when I went to bed and looked at the results as I munched my muesli the next morning.
Its fairly straight forward to use and there is a manual. A full licence is $US 25 but you get a month to play with it before having to decide.
