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Gents,
Given the new challenge just starting, I would like to present you with the Solstice Sun: http://www.perseus.gr/Astro-Solar-Scenes-Chalkida-Bridge-01.htm. |
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Thats quite the site you got there! |
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Very nice ! Liked the site of the Solar Image Gallery - Analemma as well !
Thanks , Walter
question : what is the most accurate calculation of the life expectancy of the Sun
according to the latest scientific insights ? And how is this calculation done ? |
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 Dave 
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Euvoia must be the shortest word to contain all the vowels. |
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Gents, thanks for the kind words.
Walter, our Sun is of spectral type G2V and which leads us to various extrapolations such as temperature and longevity. As a result, statements of the form "10 billion-yr life span" are based on the G2V spectral type. As for the 4.5 to 4.6 billion yr age of our Sun, this is based on Earth and where geologists (amongst others) have established our planet to be about 4.5-4.6 billion yrs old.
Huge and homogeneous volumes of hydrogen gas and dust collapse due to gravity when a small anomaly is introduced to form stars. The protoplanetary disk which remains following stellar formation leads to the formation of planets. As a result, by knowing the age of the planets (and solar system), we can derive the age of the Sun since the solar system formed immediately after the formation of the Sun.
Dave, very astute observation! |
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Euvoia must be the shortest word to contain all the vowels.
And a word which contains all of the vowels in proper alphabetic order:
"facetious"
You can add "ly" at the end if you want to count "y" as a vowel.
Another one: a word that has three consecutive doubled letters: "bookkeeper".
Thus endeth my English language trivia for the day.
--Gary |
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That was a great pic btw!
and who says we can't learn something new every day - ya'lls words will come in hand on Word Feud |
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Eunoia has the benefit of being an English word rather than Greek place name while still of the same length and vowel count.
The shortest of all words containing each vowel, pretty much by definition, is Iouea which is a kind of fossil sponge. |
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Eunoia might well be an English word, but it's evidently as Greek as Euvoia. |
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Eunoia might well be an English word, but it's evidently as Greek as Euvoia.
This is correct.
As a slight diversion, many words which begin with "eu" imply something positive. Aside from eunoia, eulogy also comes to mind. |
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Do you perhaps find G2V type stars in globular clusters like M13?
This is a good question. The problem with globulars is the fact the member stars are very dim for spectroscopy (ie. a lack of sufficient signal). I just checked and studies involve the brightest member stars and invariably and are based on very small sample sizes. Here is a good paper: http://adsabs.harvard.edu/full/1947ApJ...105..204P. |
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As a slight diversion, many words which begin with "eu" imply something positive. Aside from eunoia, eulogy also comes to mind.
And European Union? |
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Dave
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I love the European Union, it's my favourite!
... |
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Aggie the Pew hijacking topics since 23 December 2009.
You've just got to love, I think, how well esteemed vermin Anthony starts a thread with a really excellent picture and truly brilliant website and we engage in a discussion of that, science, literature, general p155 taking and politics. It sounds to me how an evening with mates should be
I still have not decided how to vote.
I still love AtP.
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You've just got to love, I think, how well esteemed vermin Anthony starts a thread with a really excellent picture and truly brilliant website and we engage in a discussion of that, science, literature, general p155 taking and politics. It sounds to me how an evening with mates should be
We are all in the same boat and, to this end, absolutely no problemo!
Eagerly waiting for the moon to become a non-issue (light pollution) so that I can get going under the night sky. |
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You've just got to love, I think, how well esteemed vermin Anthony starts a thread with a really excellent picture and truly brilliant website and we engage in a discussion of that, science, literature, general p155 taking and politics. It sounds to me how an evening with mates should be
We are all in the same boat and, to this end, absolutely no problemo!
Eagerly waiting for the moon to become a non-issue (light pollution) so that I can get going under the night sky.
I can't send you a message on this account and I won't under the other.
The point I was trying to make was that we are, I think, great friends. So we can have a wide ranging conversation ranging through almost any subject just like we could if we met socially face to face.
I've certainly very much enjoyed my face to face vermin meetings and would like to do more.
I bought one of these puppies https://www.firstlightoptics.com/william-optics/william-optics-flt-132-ddg.html 3 months ago and have used it in total for nearly 10 minutes. So I am more concerned about cloud cover than a full moon especially as it has not been truly dark here since late May and won't be until late August. |
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I bought one of these puppies https://www.firstlightoptics.com/william-optics/william-optics-flt-132-ddg.html 3 months ago and have used it in total for nearly 10 minutes. So I am more concerned about cloud cover than a full moon especially as it has not been truly dark here since late May and won't be until late August.
This is a very good apochromatic refractor and you can do a lot with it given its focal length (925mm), fairly fast optics (f7) and colour correction.
For deep-sky work, you will need a very good mount which will track the sky as well as possible as well as being able to handle the weight of the scope and any additional equipment (camera, adapters etc).
Britain is characterized with very steady skies and which is a real bonus.
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mackerelVolunteer tester
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A random diversion to the topic... but seems as good a fit here as anywhere. I was wondering the other day, if anyone has attempted to optically image the relative difference in motion of parts of a deep sky object through ultra-narrow bandwidth imaging?
I recently got my 2nd PST updated with new objective and have used it exactly once. While I can't say I've experienced it myself, I understand the rotation of the sun is sufficient that differences in tuning of the filter may be needed if you're viewing the approaching edge as opposed to the other. That got me thinking, if it works on the sun, do other bigger and more distant objects show the same effect? Could I try this on a nebula?
Problem 1: the PST has a nominal passband of about 1 angstrom, and I'm not sure that is narrow enough.
Problem 2: the stock PST is f/10 with 40mm aperture, and I have the stock blocking filter, so narrow FOV, slow, and massive vignetting if I use anything other than the tiniest sensors. My upgraded one will be worse as it is still f/10 but with 100mm aperture.
Problem 3: the narrowband filter will likely throw away a lot more light also.
Problem 4: how the hell will I tune it if I can't see anything short of some exceptionally long exposures?
Problem 5: I never did dial in the polar alignment of my mount. It is "good enough" for up to about 4 minutes at 300mm focal length with APS-C sensor. Maybe I can get away with 400mm, if it were not for f/10 compared to the f/2.8 I usually image at. Nearly 4 stops difference, is going to hurt! |
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A random diversion to the topic... but seems as good a fit here as anywhere. I was wondering the other day, if anyone has attempted to optically image the relative difference in motion of parts of a deep sky object through ultra-narrow bandwidth imaging?
I recently got my 2nd PST updated with new objective and have used it exactly once. While I can't say I've experienced it myself, I understand the rotation of the sun is sufficient that differences in tuning of the filter may be needed if you're viewing the approaching edge as opposed to the other. That got me thinking, if it works on the sun, do other bigger and more distant objects show the same effect? Could I try this on a nebula?
Problem 1: the PST has a nominal passband of about 1 angstrom, and I'm not sure that is narrow enough.
Problem 2: the stock PST is f/10 with 40mm aperture, and I have the stock blocking filter, so narrow FOV, slow, and massive vignetting if I use anything other than the tiniest sensors. My upgraded one will be worse as it is still f/10 but with 100mm aperture.
Problem 3: the narrowband filter will likely throw away a lot more light also.
Problem 4: how the hell will I tune it if I can't see anything short of some exceptionally long exposures?
Problem 5: I never did dial in the polar alignment of my mount. It is "good enough" for up to about 4 minutes at 300mm focal length with APS-C sensor. Maybe I can get away with 400mm, if it were not for f/10 compared to the f/2.8 I usually image at. Nearly 4 stops difference, is going to hurt!
Really good seeing other fellow amateurs here!
We do have deep sky objects which are moving away from us very fast while others are approaching us. Since the universe is expanding, there is a general moving away of everything from everything else.
Now, to get back to your thought: you can measure the doppler shift of quasars and where you will easily show them as being red-shifted (ie moving away). However, this entails spectroscopy.
In relation to your PST, it is restricted to h-alpha light and, as a result, you are looking at a very narrow part of the spectrum. We do use h-alpha filters in astrophotography but they are generally of interest for emission nebula which are characterized with h-alpha emissions. Also, h-alpha filters for astrophotography have a bandpass of 3 to 7 nm (depending on manufacturer and taste). |
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I have a Coronado SM90 h-alpha filter, received just last month, and which I will put into use at some point this month. I hope to have some cool images of the sun in h-alpha. |
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I have a Coronado SM90 h-alpha filter, received just last month, and which I will put into use at some point this month. I hope to have some cool images of the sun in h-alpha.
Unfortunately the filter last month did not arrive in time for the Mercury transit against the Sun's chromosphere but here is my result of Mercury against the Sun's photosphere: http://www.perseus.gr/Astro-Planet-Mer-Transit-2016-Ingress.htm |
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mackerelVolunteer tester
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I already posted my rubbish attempt of the recent Mercury transit in the photo thread. I was travelling for work so no fancy kit. Just a regular DSLR with solar film on the front of the lens.
As for my imaging idea, I'm not trying to measure the overall red-shift, but look for relative differences in red shift in parts of the subject.
Like many, I've tried narrowband imaging already, but how narrow is narrow? I currently have a set of 12nm bandwidth filters. I debated long about replacing them with 3nm ones to see if would help in my light pollution rejection, but these are still too wide for my idea. The PST filter is 0.1nm, and starts to get more interesting, if I can somehow overcome all the other problems listed previously. If parts of the subject are moving differently enough from each other, their peak emission should vary, maybe enough to be detected.
BTW I kinda decided not to try too hard on astrophotography. My location isn't really great for deep sky as I have a lot of light pollution ad unstable city air. Getting away from it isn't realistic. I did play with planets a bit, but they're a bit samey after a while, which I also get a bit of with the sun. Deep sky is the main interest, but unless I move it isn't something I can do to a greater level. |
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I already posted my rubbish attempt of the recent Mercury transit in the photo thread. I was travelling for work so no fancy kit. Just a regular DSLR with solar film on the front of the lens.
I will look it up since I missed it. I was battling thin clouds and which impacted my contrast.
As for my imaging idea, I'm not trying to measure the overall red-shift, but look for relative differences in red shift in parts of the subject.
No matter how you cut it, you are looking at spectroscopy. Simply imaging something will not yield the information you are looking for. The only suggestion I can make is to go after stars with high proper motion and which becomes especially noticeable after a few years. Here is Barnard's Star in action:
http://www.perseus.gr/Astro-Star-Dwarf-Barnard-2010.htm
Like many, I've tried narrowband imaging already, but how narrow is narrow? I currently have a set of 12nm bandwidth filters. I debated long about replacing them with 3nm ones to see if would help in my light pollution rejection, but these are still too wide for my idea. The PST filter is 0.1nm, and starts to get more interesting, if I can somehow overcome all the other problems listed previously. If parts of the subject are moving differently enough from each other, their peak emission should vary, maybe enough to be detected.
Filters with a bandpass of 12 nm are way too wide and irrespective of light pollution whereas 3 - 4.5 nm filters will get you really good contrast and will work around light pollution but you will need longer exposures (easily 15-30 minutes per integration). The 0.1 nm for the PST is way too tight.
BTW I kinda decided not to try too hard on astrophotography. My location isn't really great for deep sky as I have a lot of light pollution ad unstable city air. Getting away from it isn't realistic. I did play with planets a bit, but they're a bit samey after a while, which I also get a bit of with the sun. Deep sky is the main interest, but unless I move it isn't something I can do to a greater level.
Have you looked into photometry including variable stars and exoplanet work? |
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mackerelVolunteer tester
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Maybe I'm still not explaining it quite right. I guess you could look at it as spectroscopy, but not in the conventional manner. By taking a series of images (outside normal stacking) with different wavelength regions, I could build up a false colour image showing which regions are emitting which range of bandwidths. Then you could possibly see which areas are relatively moving towards or away from us. As already stated I do not expect this to be an easy or straightforward task, if it is even possible. How much movement would translate into how much shift? Things like that I have to work out. I'm thinking I could pre-calibrate the PST but temperature changes during imaging will likely ruin that. The PST is a low cost option so the filter on that isn't the narrowest. Still, it is all I got that could possibly do this without spending a LOT more cash.
Oh the 12nm filters, cost was a factor. Very roughly, three of those cost around as much as a single 3nm. The other reason was 12nm is much more forgiving of fast objectives. It just about copes with f/2, although I later moved to a slow for me f/2.8. If I went for narrower filters, I'd also have to slow down on imaging...
Edit: http://www.primegrid.com/forum_thread.php?id=4320&nowrap=true#94915 my mercury transit attempts |
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This is a very good apochromatic refractor and you can do a lot with it given its focal length (925mm), fairly fast optics (f7) and colour correction.
For deep-sky work, you will need a very good mount which will track the sky as well as possible as well as being able to handle the weight of the scope and any additional equipment (camera, adapters etc).
Britain is characterized with very steady skies and which is a real bonus.
I have one of these mounts https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-az-eq6-mount.html so it is solid enough I think.
I have to say it is the first time I have heard it said Britain has steady skies. We usually complain it on account of the high humidity and, here in London, the light pollution.
Still the point is moot as it has been overcast pretty much non-stop for months. I offered a prize elsewhere for the faintest object which could be photographed and identified between the offer and a couple of weeks before a Christmas Party. The current leader is at mag minus 26.8 ie the sun.
Like Mackerel I have been wondering what happens using a solar telescope on a deep-sky object. I suspect the combination of Doppler shifts and very narrow filters mean that one will see nothing but this autumn I will try on M42. |
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I have one of these mounts https://www.firstlightoptics.com/skywatcher-mounts/skywatcher-az-eq6-mount.html so it is solid enough I think.
SW makes fairly good mounts. With guiding and periodic error correction, you should be able to produce quality deep sky results.
I have to say it is the first time I have heard it said Britain has steady skies. We usually complain it on account of the high humidity and, here in London, the light pollution.
Actually one reason for the steady skies is indeed the humidity. Some of the best planetary imagers in the world are in the UK and around Selsey.
Like Mackerel I have been wondering what happens using a solar telescope on a deep-sky object. I suspect the combination of Doppler shifts and very narrow filters mean that one will see nothing but this autumn I will try on M42.
Keeping in mind the incredibly tight bandpass on a mag -26.8 olject, anything else relatively much dimmer will not be visible. How about trying it on the moon and which is around mag -12.7 when full? |
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Damian Peach the noted planetary photographer uses http://weather.unisys.com/gfs/gfs.php?inv=0&plot=300®ion=eu&t=9p to predict seeing (among other techniques like actually going outside and looking down a telescope).
Purply-pink tends to correlate with good seeing and light blues through greens to red poor seeing. |
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mackerelVolunteer tester
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actually going outside and looking down a telescope
Recently, this is where I've been failing... |
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actually going outside and looking down a telescope
Recently, this is where I've been failing...
The best telescope is the one you use Mackerel which is why I think the 65mm altaz refractor I got 50 years ago is best. If there was a hint of a clear sky it'd be out. I was almost as keen as Rick is to get his chopper out.
These days it takes a considerable time to drag at least 100kg of kit including one or two computers out. I have to set it all up and align (although one of these http://www.qhyccd.com/PoleMaster.html has speeded alignment up). I have to keep the bits that need to be warm warm and the bits that need to be cold cold. I have to get the autoguider setup and working.
Sunset here is 2122 and sunrise 0444 and it is not even remotely dark until well after sunset and plainly bright by 0300. Worse for you.
I too am not inclined to cart a literal shed load of stuff out on the off chance it'll be clear. I've made a step against that by buying one of these https://www.firstlightoptics.com/az-goto/skywatcher-skymax-127-synscan-az-goto.html . It is not as good as the main outfit but it does mean despite the awful skies in the unlikely event it is clear I am actually out seeing stuff. |
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mackerelVolunteer tester
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Will write more when I get home. I don't often do much visual, and am primarily into imaging. For deep sky that is DSLR based as I never quite justified to myself going for a dedicated cooled sensor, and I'd have to upgrade everything else at the same time to match.
I do have the NEQ6 too, on fixed pier. The idea was I'd get the polar alignment done really well once, and leave it. That never happened... I did a rough alignment which was good enough, then knocked that out and never got around to readjusting it. I've probably done less than 3 nights of deep sky in the last two years.
I'll have to show a pic of my "laptop stand" when I get home :)
Oh, as for darkness, did you say you were in London? I'm on same latitude if so, and would expect similar (lack of) darkness in the summer months. |
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These days it takes a considerable time to drag at least 100kg of kit including one or two computers out. I have to set it all up and align (although one of these http://www.qhyccd.com/PoleMaster.html has speeded alignment up). I have to keep the bits that need to be warm warm and the bits that need to be cold cold. I have to get the autoguider setup and working.
One means to bypassing this madness is to have a permanently aligned mount outside which is very well protected from the elements. All that remains thereafter is to mount the scope and get going. This is what I have done.
Right now I have less than six hours of darkness. :-( |
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Oh, as for darkness, did you say you were in London? I'm on same latitude if so, and would expect similar (lack of) darkness in the summer months.
I am at 51deg 25sec N. I had for some reason thought you were further north. |
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does an iPhone 6se count |
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mackerelVolunteer tester
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Just fired up the GPS and I'm currently (at work) 51deg 32.3 N so technically I am slightly more north. I was up north a bit earlier this year on work travels, including when I took the Mercury transit pics and collecting the modified PST. |
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does an iPhone 6se count
For what?
Having an extra bumhole? Yes.
For being a scientist? May be. I shall make a post about how you can detect cosmic rays using it later. Brink knows one way.
For being cool. Nope. |
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does an iPhone 6se count
For what?
For being cool. Nope.
bummer as I am the coolest |
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does an iPhone 6se count
For what?
For being cool. Nope.
bummer as I am the coolest
Bet ya gotta a really "cool" case for it too...
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There's someone in our head but it's not us. |
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I thought it would be amusing to take a picture of a cosmic ray. I read about the idea somewhere but now can not recall where. I don't claim it as original.
Cosmic rays are usually fast moving protons.
Droves of them come charging (pardon the pun) in and interact with atoms in the upper atmosphere.
The result of the collision is a beast called a pi meson which lives for a few nanoseconds. It then turns into a muon which is heavy, 200x the mass of an electron, charged with the same or exactly opposite charge of an electron, long lived at a couple of microseconds and going like stink. There are a fair few of these chaps around. At first sight you'd think that if they only live for 2 microseconds and they are formed high in the atmosphere then even if they are going at the speed of light then they won't go more than a couple of hundred metres but that forgets the time dilation of fast moving objects as predicted by Einstein. They go a fair bit further than that before they decay into an electron or a positron and two neutrinos.
So we have lots of big, fast moving and thus high energy particles with an electrical charge. That means they will eventually interact with other materials such as for example a camera sensor. There is a decent probability that one will interact with a camera sensor in an exposure of a couple of minutes.
I put the body cap on my camera (I could have left the lens on but didn't) engaged long noise exposure reduction and took several several minute exposures. Careful review of the results often but not always showed tracks like these (shown here in negative). They could be mere artifacts or the result of radioactive decay but the very strong probability is that They Came From Outer Space.
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I thought it would be amusing to take a picture of a cosmic ray.
Cosmic ray hits are VERY common for those doing CCD work. They show up rather often as squiggly lines and are removed during processing using an STD rejection. |
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So the long years of wearing tinfoil hats were without purpose ...
TheDawgz gotta go blog about this important news.
As a matter of course we will be certain to credit your work on this very controversial subject.
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There's someone in our head but it's not us. |
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So the long years of wearing tinfoil hats were without purpose ...
TheDawgz gotta go blog about this important news.
As a matter of course we will be certain to credit your work on this very controversial subject.
I am very sure it is important that you keep wearing the tinfoil hats. |
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Oh and Rick. |
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Obviously about Rick.
I thought everyone knew that.
Then TheDawgz posted and I thought we knew about that too.
TRR
PS
Anyone seen Z-san? |
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Anyone seen Z-san?
The one-man wrecking crew is busy .... piling up millions. I admire him!!! |
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Anyone seen Z-san?
The one-man wrecking crew is busy .... piling up millions. I admire him!!!
He is The Steely Eyed Missile Man. I just worry that I included him in the same post as one mentioning Rick and TheDawgz. Oh and you now you mention it. |
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mackerelVolunteer tester
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My "laptop stand" :)
https://lh5.googleusercontent.com/-z0A-wMKCFlg/T23wsmKdzmI/AAAAAAAAHtY/0pSnKorzMog/s800/sunsetup.jpg
Very old pic, before I got planetary sensors and the EQ6... I'm still using that laptop stand. |
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My "laptop stand" :)
https://lh5.googleusercontent.com/-z0A-wMKCFlg/T23wsmKdzmI/AAAAAAAAHtY/0pSnKorzMog/s800/sunsetup.jpg
Very old pic, before I got planetary sensors and the EQ6... I'm still using that laptop stand.
Now this is both funny and creative! LOL.
Edit: Here are my toys: http://www.perseus.gr/Astro-Equipment.htm ... bottom part of the page needs serious updating.
Edit: I also have to add a more recent acquisition: an Astro-Physics 130/f6.3 Gran Tourismo apochromatic refractor and for which I was on the waiting list for over NINE years. Telescopes from AP are that much in demand and not to mention the existence of a serious and active black market. |
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@TheFurryOne - of course my case is very cool - it's red
@RR - for yours and TheFurryOne's information, my hat is lead lined not tin foil (note my pic) |
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My "laptop stand" :)
https://lh5.googleusercontent.com/-z0A-wMKCFlg/T23wsmKdzmI/AAAAAAAAHtY/0pSnKorzMog/s800/sunsetup.jpg
Very old pic, before I got planetary sensors and the EQ6... I'm still using that laptop stand.
Now this is both funny and creative! LOL.
Edit: Here are my toys: http://www.perseus.gr/Astro-Equipment.htm ... bottom part of the page needs serious updating.
Edit: I also have to add a more recent acquisition: an Astro-Physics 130/f6.3 Gran Tourismo apochromatic refractor and for which I was on the waiting list for over NINE years. Telescopes from AP are that much in demand and not to mention the existence of a serious and active black market.
that's some serious equipment |
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I put the body cap on my camera
hmmm no wonder the pictures look that way |
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I'm pretty sure TheDawgz are well shielded from solar/cosmic radiation by remaining under the porch. :-) If only it were cooler.
At one point I read (and this could be urban legend) that a coast-to-coast (USA) round-trip at normal aircraft altitude was the equivalent of getting a full chest x-ray at a hospital. And I worked with people that did this every few weeks. One more reason I'm glad I'm out (not that I traveled much for work).
Enjoying the glow from near sea level,
--Gary |
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I'm pretty sure TheDawgz are well shielded from solar/cosmic radiation by remaining under the porch. :-) If only it were cooler.
--Gary
It has been a bit warm; even under the porch.
For the first 22 days of June, we have seen ...
19 days that were > 100F (37.8C) of those 19 days,
7 days that were > 110F (43.3C) of those 7 days,
2 days that were > 115F (46.1) and of those 2 days
1 day which was exactly 120F (48.9C)
Phoenix is in for a long hot summer!
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There's someone in our head but it's not us. |
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I'm pretty sure TheDawgz are well shielded from solar/cosmic radiation by remaining under the porch. :-) If only it were cooler.
--Gary
It has been a bit warm; even under the porch.
For the first 22 days of June, we have seen ...
19 days that were > 100F (37.8C) of those 19 days,
7 days that were > 110F (43.3C) of those 7 days,
2 days that were > 115F (46.1) and of those 2 days
1 day which was exactly 120F (48.9C)
Phoenix is in for a long hot summer!
120! Is that a record?
Right now it is 73 F in Mpls
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A quick web search shows the all-time high temperature in Phoenix as 122F.
When I was there in a January about 10 years ago, it was the coldest day there in years. Ice on the streets and sidewalks. Bad for running.
--Gary |
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Here is a picture of 2 telescopes. For scale the blue object in the case is credit card sized.
The black telescope has a notional aperture of 127mm and a focal length of 1500mm. It weighs a couple of kilograms. It is easy to carry with one hand
The white telescope has a notional aperture of 132mm and a focal length of 925mm. It weighs about 10kg. It is bulk and weight mean that two hands are needed to pick it up and for mounting it on a tripod prefarbly two people.
Images from the black telescope will be a somewhat fainter and rather larger than those from the white telescope. The black telescope is made by a well-reputed company and is widely regarded as good instrument. The cost of the black telescope complete with eyepieces, a computer controlled mount and tripod is almost exactly 10% of the price of the bare white tube.
The black telescope is very good for visual use and would likely be better than the white one for taking pictures of planets. For taking pictures of galaxies and star clusters the white telescope wins hands down.
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The boys and their toys |
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The boys and their toys
I just like bragging that I have got a 5 incher. |
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The boys and their toys
I just like bragging that I have got a 5 incher.
It's not the length it's the girth |
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mackerelVolunteer tester
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Here's my main astro kit. I forgot the credit card sized object for scale but the gold tube on the left middle scope is roughly comparable to the short side of the credit card.
While at it, that left middle one is a Coronado Personal Solar Telescope, simply called PST for short. It doesn't need to be big as the sun is pretty bright, and this is the lowest cost route to a type of solar viewing that looks at a specific hydrogen emission. This is nominally 40mm aperture, 400mm focal length. Note the eyepiece holder has been temporarily taken off.
However the law of physics say, if you want more detail, you need to go large. That's what the long one at the bottom is for. I picked up a used PST and got the front part replaced with a Tal 100 RS. So 100mm aperture, 1000mm focal length. It should produce about 2.5x the resolution of the standard one. The blue box on the end is an astro-imaging camera, but you could equally put an eyepiece there and have a look.
Top right is my planetary scope. 200mm aperture, 2000mm focal length. Got this used, and it is really ancient but still works. Only annoyance is I never quite dialled in the collimation even upgrading it with a set of Bob's knobs, so I don't think it is giving as much detail as it could.
And finally, top left is actually a camera lens, but I use it for deep sky imaging. It is nominally 300mm focal length, f/2.8, but if you do the sums that should be 107mm aperture. It has a 105mm filter thread on it, so there is a bit of rounding going on somewhere.
Now... if only I had time to use any of it...
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Gents,
Great pics. Always nice to see equipment photos.
I am waiting for a Celestron 14" EdgeHD to be shipped from California. Once it arrives, I will post some pics.
If the weather holds Saturday evening, I will be off to Mount Helmos 90 minutes west of Athens and near the facilities of the Aristarchus telescope at 2300+ meters altitude. With New Moon approaching, this is an opportunity for some widefield imaging under very dark skies (mag 7).
Edit: http://www.celestron.com/browse-shop/astronomy/optical-tubes/edgehd-14-optical-tube-assembly |
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The frankish Tower of Oinoe at Marathon, Greece and which is dated circa 1250 AD: http://www.perseus.gr/Astro-Star-Trails-Tower-Marathon-Oinoe-2016.htm.
Total exposure time is 5.5 hrs.
Edit: Britain has some incredible castles begging for such work! |
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Aghia Foteini, Ancient Mantineia, Greece
A very controversial church constructed in the early 1970's where the architect sought to combine elements from the time of ancient Greece, the Byzantium and the modern era. This most unorthodox orthodox place of worship even had the Church of Greece express its dissatisfaction.
Further details at http://www.perseus.gr/Astro-Star-Trails-Ancient-Mantineia-Aghia-Foteini-2016.htm. |
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It is not good as your pictures,but I am trying :)
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The frankish Tower of Oinoe at Marathon, Greece and which is dated circa 1250 AD: http://www.perseus.gr/Astro-Star-Trails-Tower-Marathon-Oinoe-2016.htm.
Total exposure time is 5.5 hrs.
Edit: Britain has some incredible castles begging for such work!
NASA AstroPhoto of the Day honours over the weekend: http://apod.nasa.gov/apod/ap160716.html. |
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It is not good as your pictures,but I am trying :)
Very respectable efforts. The moon is awfully bright and with tremendous dynamic range whereas planets require a very steady atmosphere and good focal length. |
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mackerelVolunteer tester
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Crun-chi, nice efforts there. Just be careful on the moon not to blow out the highlights, especially the two bright spots to the right (anyone know their name?). What did you use for Jupiter? That looks comparable in visual quality to my efforts with 8" SCT, but I think I could in theory get better for the size.
Also congrats Anthony, well deserved. I used to hang out on some other astro-imaging forums and it was APODs everywhere there... I never tried myself though. |
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Mack,
I know the surface of the moon quite well. Which two features are you referring two? |
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Crun-chi, nice efforts there. Just be careful on the moon not to blow out the highlights, especially the two bright spots to the right (anyone know their name?). What did you use for Jupiter? That looks comparable in visual quality to my efforts with 8" SCT, but I think I could in theory get better for the size.
Also congrats Anthony, well deserved. I used to hang out on some other astro-imaging forums and it was APODs everywhere there... I never tried myself though.
There was two try`s with Jupiter: first was using 18 MP photo ( many of them) then stacking together ,and second was made by using HD movie on camera, and then stacking again..
This is still very first trys so I am on good way.
I just try to make photo of M42 and M14, but I must process them....
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It is not good as your pictures,but I am trying :)
Very respectable efforts. The moon is awfully bright and with tremendous dynamic range whereas planets require a very steady atmosphere and good focal length.
Thanks for nice words!
Moon, when is old only few days is the best for making photo ( in my opinion)
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mackerelVolunteer tester
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Mack,
I know the surface of the moon quite well. Which two features are you referring two?
In Crun-chi's pic, it is to the right of the image. There's two bright spots there that often catches me out but it was kept in control in that image. The 2nd image doesn't quite show that area but is just below and there are signs of blowing. |
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There was two try`s with Jupiter: first was using 18 MP photo ( many of them) then stacking together ,and second was made by using HD movie on camera, and then stacking again..
I was actually more interested in the optics than the camera :) Air conditions and optics seem to be the bigger limiting factors. |
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Crun-chiVolunteer tester
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There was two try`s with Jupiter: first was using 18 MP photo ( many of them) then stacking together ,and second was made by using HD movie on camera, and then stacking again..
I was actually more interested in the optics than the camera :) Air conditions and optics seem to be the bigger limiting factors.
I have basic telescope 115/900 reflector, two eyepiece and Barlow 2x lens...
and lot of time :)
Camera is Canon 1100D
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mackerelVolunteer tester
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Wow... I never managed anything planetary that good with a DSLR. I went the dedicated planetary cam route in the end (glorified webcam). |
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There was a gorgeous conjunction this evening involving the very young crescent Moon with Venus and Jupiter.
Here is a sample peek: http://www.perseus.gr/Astro-Conjunctions-20160903.htm |
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We have an interesting dilemma for those living in the northern hemisphere and where Earth's closest approach to the Sun (aka perihelion) occurs in the heart of winter.
Here is a comparison of mine between perihelion and aphelion from twelve yrs ago: http://www.perseus.gr/Astro-Solar-Scenes-Aph-Perihelion.htm.
The effect involving the Moon as it orbits Earth is even more dramatic and easily discernible to the experienced eye: http://www.perseus.gr/Astro-Lunar-Scenes-Apo-Perigee.htm. |
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I saw a similar (not the same spacing) conjunction of the moon and planet as I was driving home after the new year. No camera on me though.
I haven't consciously noticed variation in apparent sun size, but did with the moon. In my early days I was using a Mak on DSLR, and by chance the combination of sensor size and focal length meant that depending on how far the moon was at the time, it may or may not be taken in one shot. |
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The variation in the apparent diameter of the Sun is virtually impossible to notice naked eye (with a filter) or through an eyepiece.
I like your comment about the Moon and how your effective focal length can make or break your ability to get the whole disk. |
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Here is a picture of the moon I took a few minutes ago
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I saw a similar (not the same spacing) conjunction of the moon and planet as I was driving home after the new year. No camera on me though.
That was probably Venus. The moon and Venus were very close together in the sky on New Year's day, and Venus was exceptionally bright. Mars was also visible, but a bit further away and a lot dimmer.
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Have any of you observed Venus during the day? You would be very surprised at how easy Venus is to see naked eye provided your eyes focus properly for infinity and you know where to look.
Once every few years we have Venus and the Moon being very close to each other during the day and this will help one realize how bright and visible Venus can be in broad daylight since one can use the Moon as a signpost to locate Venus in the immediate vicinity when such a conjunction does occur. |
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Have any of you observed Venus during the day? You would be very surprised at how easy Venus is to see naked eye provided your eyes focus properly for infinity and you know where to look.
Once every few years we have Venus and the Moon being very close to each other during the day and this will help one realize how bright and visible Venus can be in broad daylight since one can use the Moon as a signpost to locate Venus in the immediate vicinity when such a conjunction does occur.
I have not, but if I get a clear day I'll look. I have an iPhone app ("Skyview") that shows where every naked-eye visible celestial object is overlaid on the camera video, so finding it should be easy enough.
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Have any of you observed Venus during the day? You would be very surprised at how easy Venus is to see naked eye provided your eyes focus properly for infinity and you know where to look.
Once every few years we have Venus and the Moon being very close to each other during the day and this will help one realize how bright and visible Venus can be in broad daylight since one can use the Moon as a signpost to locate Venus in the immediate vicinity when such a conjunction does occur.
I have not, but if I get a clear day I'll look. I have an iPhone app ("Skyview") that shows where every naked-eye visible celestial object is overlaid on the camera video, so finding it should be easy enough.
In this case it should be quite easy to spot with the help of your app. Simply give your eye a moment to properly adjust for true infinity. I am sure there is an evolutionary aspect to it but the eye treats anything around 400m or greater as "infinity" and which will obviously not work with the overhead sky.
You are in for a treat! |
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http://www.heavens-above.com/PlanetSummary.aspx?lat=40.7128&lng=-74.0059&loc=New+York&alt=10&tz=EST suggests that Venus, Mercury and Mars could be possible. Obviously be wary waving binoculars or telescopes around if the sun is up.
The early telescope studies on Mercury were mainly done in daylight since that was the only time it was high in the sky. |
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Tim, thanks for mentioning Mercury since this is something else I was meaning to bring up. It is amazing how few people including professional astronomers have seen Mercury naked eye.
I will check later to see when we have the next greatest elongation and which will allow for the naked eye observation of Mercury 30 minutes after sunset and for another 60-90 minutes thereafter. |
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Tim, thanks for mentioning Mercury since this is something else I was meaning to bring up. It is amazing how few people including professional astronomers have seen Mercury naked eye.
I will check later to see when we have the next greatest elongation and which will allow for the naked eye observation of Mercury 30 minutes after sunset and for another 60-90 minutes thereafter.
It is in the link; maximum western elongation is Jan 19 (ie mornings) and maximum east is April 1 |
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Tim, thanks for mentioning Mercury since this is something else I was meaning to bring up. It is amazing how few people including professional astronomers have seen Mercury naked eye.
I will check later to see when we have the next greatest elongation and which will allow for the naked eye observation of Mercury 30 minutes after sunset and for another 60-90 minutes thereafter.
It is in the link; maximum western elongation is Jan 19 (ie mornings) and maximum east is April 1
Around April 1st is the most convenient for many people due to it being evening. Here is an example from two years ago: http://www.perseus.gr/Astro-Planet-Mer-201405-Elong.htm.
As I mentioned earlier, seeing Mercury with the naked eye is a serious accomplishment and something which very few people can claim. |
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Ya'll got me to pull out my old Celestron Nexstar 4SE.
It's been such a long time that I have almost forgot how to use it. LOL
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Ya'll got me to pull out my old Celestron Nexstar 4SE.
It's been such a long time that I have almost forgot how to use it. LOL
Good to see such an interest in astronomy in this group. |
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Ya'll got me to pull out my old Celestron Nexstar 4SE.
It's been such a long time that I have almost forgot how to use it. LOL
Enjoy; it is handy piece of kit.
Here is another lunar picture. The prominent valley through the mountains in the centre is called Vallis Alpes and is about 80 x 11 miles. To the picture left there is a crater called Cassini which has two craters within it. The smaller of those called Cassini B is 5 miles in diameter.
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http://snowporing.deviantart.com/art/Moon-20081206-105589857
To combine two things into one, at the above link is possibly my best detail shot of the whole moon ever (if partially illuminated), where those features can also be found at the top of the image. Hit the download button on right for a bigger version.
What optics did I use? A Nexstar 4SE :) That was before I tried stacking images so that's a mosaic of 5 shots from a DSLR. |
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Very nice. And it helped me locate another picture where my note taking let me down. |
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I've spotted Jupiter naked-eye in daylight when camping at altitude 9000' or so... nice clear, dry, air, and not so much of it to deal with. Mercury, a few times, but either pre-dawn or post-sunset.
skyandtelescope dot com has some free (no subscription needed) charts linked from their main page, for basic planetary observing, including Uranus and Neptune (no naked-eye on those, obviously).
Happy gazing,
--Gary |
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I've spotted Jupiter naked-eye in daylight when camping at altitude 9000' or so... nice clear, dry, air, and not so much of it to deal with.
This is impressive!
I caught the ISS transiting Jupiter during the day but I had trouble focusing due to a dim disk.
Edit: Here is the result: http://www.perseus.gr/Astro-Sat-ISS-2010-05-29.htm. |
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Another one with the Nexstar 4SE, this time hand held! It's the least worst shot I got of the ISS as it passed overhead.
I had to hand hold it since I had no other way to track it. Previous attempts with a camera lens didn't quite have enough reach.
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This is a common strategy where the camera is shooting continuously and one manually tracks the ISS through the finderscope.
My mount allows for the automatic tracking of the ISS. |
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I've spotted Jupiter naked-eye in daylight when camping at altitude 9000' or so... nice clear, dry, air, and not so much of it to deal with.
This is impressive!
I caught the ISS transiting Jupiter during the day but I had trouble focusing due to a dim disk.
Edit: Here is the result: http://www.perseus.gr/Astro-Sat-ISS-2010-05-29.htm.
It looks like some alien ship :)
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I finally got around to doing more of the processing from the data a couple weeks back... enough to see something at least. Here's a "work in progress" of Orion nebula, with only minor adjustments so far. I did try more but I made it worse... too out of practice!
This was possibly my first time using the Canon 7D mk2 for astro. It is supposed to be one of the best sensors Canon made so far with regard to noise levels. Obviously not going to rival a cooled sensor which I'm still not going to pay for. Well... it wasn't perfect. For reasons unknown there was banding in my Orion shots if I really dig deep, but oddly none visible in the rosette shots.
81 subs of 30s each. Canon 7D mk2 + Sigma 120-300 OS at 300mm f/2.8, astronomik CLS-CCD filter. PixInsight + Photoshop.
Rosette will be a trickier process as there is a lot more red, which I find more difficult to handle. That reminds me, I never got around to downloading my Ha and OIII data on top of the RGB...
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Very nice effort.
I have the Canon EOS 6D which I really like. It is also characterized with very low noise as well.
Since my primary interest for the 6D is astophotography, it has been modified with the addition of Baader's filter for enhanced h-alpha sensitivity while still very much usable for daytime photography with the proper custom white balance. |
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I had a thought on my banding issue... I think as Orion is so bright, I used a different ISO setting than for Rosette which may be a contributing factor.
I did have a 450D full spectrum modified, but there was an unacceptable amount of dust so I'm now running it filterless. However the sensor is showing its age so I don't use it for astro any more. It is still my terrestrial NIR camera on the rare occasion I do that. I'm not actually sure where the camera is right now. |
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I did have a 450D full spectrum modified, but there was an unacceptable amount of dust so I'm now running it filterless. However the sensor is showing its age so I don't use it for astro any more. It is still my terrestrial NIR camera on the rare occasion I do that. I'm not actually sure where the camera is right now.
NIR photography is something I have looked into as well and I hope to get into it one day. Ditto for UV. |
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NIR is interesting and not too difficult to get into. I even tried it for astro although didn't get anything interesting. For stars it was interesting to see familiar constellations with different relative star brightness than used to, but I didn't investigate further. My vague hope was that going beyond 800-something nm would avoid another sodium emission wavelength, but sensitivity was so far down by then there wasn't much of anything.
UV I only indirectly tried, using the same filterless camera and the Baader Ca-K filter. This is not ideal, since it is somewhat narrowband but it was enough to show the patterns on flowers not visible normally. |
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81 subs of 30s each. Canon 7D mk2 + Sigma 120-300 OS at 300mm f/2.8, astronomik CLS-CCD filter. PixInsight + Photoshop..
How do you find PixInsight? I tried the free trial but it seemed horribly complicated tho' powerful. I use MaximDL and/or DSS and Photoshop at the moment. |
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How do you find PixInsight? I tried the free trial but it seemed horribly complicated tho' powerful. I use MaximDL and/or DSS and Photoshop at the moment.
There is a learning curve with it, and I've barely scratched its power. I've never had that good results with DSS, and have no experience with MaximDL.
My typical workflow is:
1 - integrate to create flat
2 - use flat to calibrate subs (I don't do darks or bias)
3 - register
4 - stack (good rejection options, typically use winsorised sigma clip + absolute clips to remove null data. My mount alignment is slightly off so I get free dithering which aids the rejection of hot pixels, as well as planes and satellites from the sigma clip)
5 - background gradient removal (a tricky one to do, auto just fails, semi-manual time consuming)
6 - stretch/levels/curves
7 - export to PS for more cosmetic tinkering
That probably isn't much different from other staking software. There are a lot of other functions I haven't really used. I think they want it to be a one stop package, although the finishing parts I still find easier to do in PS. At least it is buy once with lifetime updates.
The last image I posted was steps 1-4 above, skipped 5, minimal amounts of 6+7. |
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PixInsight has a very steep learning curve. I was turned off a few years ago when the software would only work if you were connected to the internet (for verification purposes).
I religiously use CCDStack and a typical workflow includes the following:
(0) prepare master flat and master bias ... master dark from personal library
(1) calibration (master dark, master flat, master bias)
(2) bloom removal
(3) multi-point alignment
(4) FWHM normalization between subs using the best one as reference
(5) background normalization
(6) Sigma reject
(7) average combine
(8) steps (1) to (7) for each filter (ie. L, R, G, B) -> master Lum, master Red, master Green, master Blue
(9) Pinpoint astrometry (Maxim DL) using master Red
(10) Aladin + eXcalibrator -> to determine coefficients for G2V calibration
(11) using master Lum as reference, align master Red, master Green, master Blue
(12) deconvolution (Positive constraint) on master Lum (50 and 75 iterations)
(12.1) background normalization between master Red, master Green, master Blue
(13) use coefficients from (10) for RGB combine and/or LRGB for the two versions described in (12)
(14) non-linear stretch (DDP)
(15) onto Photoshop ... noise reduction using Neat Image
(16) use the two versions from (12) using a layer mask to correct for small artifacts from bright stars due to "75 iterations"
(17) small adjustments with levels, curves, saturation, colour balance
(18) pixel repair (due to nonlinear stretch)
(19) save onto disk as 16-bit TIFF
(20) save onto disk also as 8-bit TIFF -> slight processing when converting to JPEG due to light USM |
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These are some nice images. I used to use a online timeshare service for high end telescopes so I can produce data for the AAVSO. Did that for quite a few years actually. Nice to see some astroheads in the team! |
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Another one with the Nexstar 4SE, this time hand held! It's the least worst shot I got of the ISS as it passed overhead.
I had to hand hold it since I had no other way to track it. Previous attempts with a camera lens didn't quite have enough reach.
That is VERY impressive work!! Bravo!!!!!
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This is the business end of one of the two systems I run at the New Forest Observatory.
The other observatory houses a C11 with Hyperstar III :)
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Greg, no coincidence you are using Canon 200mm lenses since exoplanet search teams use these lenses in an array as well in their all-sky surveys in both hemispheres.
Really good-looking set-up. |
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the New Forest Observatory.
Small world! We quite often holiday at the Holland's Wood campsite just outside Brockenhurst. Good dark skies, although not as good as Kielder Forest, which is just an hour down the road from home, or Galloway Forest park. On the plus side, I suspect there are a lot more clear nights.
- Iain
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3073428256125*2^1290000-1 is Prime! |
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Greg, no coincidence you are using Canon 200mm lenses since exoplanet search teams use these lenses in an array as well in their all-sky surveys in both hemispheres.
Really good-looking set-up.
Cheers Anthony - but I think the SuperWASP guys use the (not now available) f#1.8 lenses - way above my payscale - I have the very cheap f#2.8 lenses :)
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the New Forest Observatory.
Small world! We quite often holiday at the Holland's Wood campsite just outside Brockenhurst. Good dark skies, although not as good as Kielder Forest, which is just an hour down the road from home, or Galloway Forest park. On the plus side, I suspect there are a lot more clear nights.
- Iain
Not only a lot more clear nights - but also a lot more nights when you do actually get a night (and not just twilight) :)
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mackerelVolunteer tester
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Not only a lot more clear nights - but also a lot more nights when you do actually get a night (and not just twilight) :)
I seem to recall you have concerns about the changing nature of street lighting. How's that working for you?
I've noticed they started replacing "as needed" the old low pressure sodium ones with white LEDs around here, and they look pretty bright... |
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New toy arrived today. Photos of the monster to follow shortly. |
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Photos of the monster to follow shortly.
We prefer it if you'd keep them between you and your significant other ;)
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Twitter: IainBethune
Proud member of team "Aggie The Pew". Go Aggie!
3073428256125*2^1290000-1 is Prime! |
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Photos of the monster to follow shortly.
We prefer it if you'd keep them between you and your significant other ;)
I am one of the few people who brag of having a 132mm monster. |
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Photos of the monster to follow shortly.
We prefer it if you'd keep them between you and your significant other ;)
I am one of the few people who brag of having a 132mm monster.
Just a little patience for the 254mm monster. I am waiting for clear blue skies. |
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Photos of the monster to follow shortly.
We prefer it if you'd keep them between you and your significant other ;)
LOL! |
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So you have to use millimeters instead of inches. Sounds kinda small |
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So you have to use millimeters instead of inches. Sounds kinda small
It is the cold that does it. |
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Hi Mackerel - sorry only just seen your question.
Well the answer to the LEDs is "mixed bag".
The sky is MUCH darker now which means I can actually do meteor photography with the DSLR and no IDAS filter.
BUT - the overall skyglow has cost me (I would guess) about 2 magnitudes now that I am surrounded by LED lighting. I saw the skyglow getting slowly worse for about 3 or 4 years as the LEDs made their way towards me.
In other words - although the sky appears a lot darker to the eye with LED lighting - the IDAS filters cut out all the Sodium skyglow very efficiently, so although the sky was a sickly yellow/orange to the eye - with the IDAS filter in it was considerably "darker" than I have now with the LEDs.
But fortunately I can still do work from here.
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Canyonlands National Park, circa 1999; scan of a print. Sorry for the graininess.
Gary++ |
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Greg, his fair lady and I shared the odd beverage today. And very pleasant it was too. In passing I mentioned some pictures I had taken of the ISS transiting the moon. They were shared here a couple of years ago but I think they bear republication
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Greg, his fair lady and I shared the odd beverage today. And very pleasant it was too.
And what was odd about it? |
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Greg, his fair lady and I shared the odd beverage today. And very pleasant it was too.
And what was odd about it?
We each had a non zero (and integer number) of beverages. Some of us had an even number of beverages. Some of us had a prime number of beverages. The total number of beverages was prime and since there were three of us in total we had an odd number of beverages. |
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Greg, his fair lady and I shared the odd beverage today. And very pleasant it was too.
And what was odd about it?
We each had a non zero (and integer number) of beverages. Some of us had an even number of beverages. Some of us had a prime number of beverages. The total number of beverages was prime and since there were three of us in total we had an odd number of beverages.
Greg had 3, his fair lady had 1 and you had 2 |
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Greg, his fair lady and I shared the odd beverage today. And very pleasant it was too.
And what was odd about it?
We each had a non zero (and integer number) of beverages. Some of us had an even number of beverages. Some of us had a prime number of beverages. The total number of beverages was prime and since there were three of us in total we had an odd number of beverages.
Greg had 3, his fair lady had 1 and you had 2
Which would make 6.
And no the answer wasn't that he had 1, his missus 2 and I had 190. |
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Greg, his fair lady and I shared the odd beverage today. And very pleasant it was too.
And what was odd about it?
We each had a non zero (and integer number) of beverages. Some of us had an even number of beverages. Some of us had a prime number of beverages. The total number of beverages was prime and since there were three of us in total we had an odd number of beverages.
Greg had 3, his fair lady had 1 and you had 2
Which would make 6.
And no the answer wasn't that he had 1, his missus 2 and I had 190.
Yeah was thinking about that later and realized the total wasn't odd, just not correct. |
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Yeah was thinking about that later and realized the total wasn't odd, just not correct.
It is easy to do*. In fact two of us had a tea and a coffee and the third just a coffee.
*Edit. Easy to do in the sense of easy to make silly errors. |
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Tomorrow we have interior solar conjunction with Venus being less than 10 degrees away from the Sun while showing a gorgeous 1% crescent phase. I have pristine transparency right now and I will calibrate everything later today for a run at Venus tomorrow midday with my TEC Mak-Cas (5000mm focal length) and an IR Pass filter (850nm) to maximize contrast. |
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Tomorrow we have interior solar conjunction with Venus being less than 10 degrees away from the Sun while showing a gorgeous 1% crescent phase. I have pristine transparency right now and I will calibrate everything later today for a run at Venus tomorrow midday with my TEC Mak-Cas (5000mm focal length) and an IR Pass filter (850nm) to maximize contrast.
Does an interior solar conjunction mean the Sun is this side of Venus? Sorry :) |
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Dave
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Right now low southeast UK if you can see Jupiter all 4 Galileans are visible. I don't have the means to take a photo right now with my myriad of feable basic equipment but it is the first time I have seen all 4 at once. |
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Eagerly waiting for night time temps to rise a little it. I have very low tolerance for anything below 16d C or so but I can easily handle heat waves. |
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Tomorrow we have interior solar conjunction with Venus being less than 10 degrees away from the Sun while showing a gorgeous 1% crescent phase. I have pristine transparency right now and I will calibrate everything later today for a run at Venus tomorrow midday with my TEC Mak-Cas (5000mm focal length) and an IR Pass filter (850nm) to maximize contrast.
Does an interior solar conjunction mean the Sun is this side of Venus? Sorry :)
Greg of Borg,
Congrats on today's EPOD: http://epod.usra.edu/blog/2017/04/odd-structure-near-regulus.html. |
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Jupiter is at opposition later this week, so maybe a good time for those of you with decent 'scopes to drag them out. (weather permitting, of course)
Jovially,
Gary++ |
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http://www.diyphotography.net/nasa-makes-entire-media-library-publicly-accessible-copyright-free/
Gary++ |
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Thank you Anthony :)
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Deep sky imager and experimental mathematician.
Emeritus Professor of Photonics
3438759891285*2^1290000-1 is Prime! |
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Last night there was a close encounter between Jupiter and a 12-day old Moon. This was the scene over the New Forest Observatories:
http://www.newforestobservatory.com/wordpress/wp-content/gallery/projects/Moon_Jupiter_Half.jpg
Greg
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Deep sky imager and experimental mathematician.
Emeritus Professor of Photonics
3438759891285*2^1290000-1 is Prime! |
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Very nice. I had hoped to have a go but hereabouts it has been overcast for a long time.
I am hoping to have a punt at Jupiter with a very long focal length later this week if the weather proves as promised.
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