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  1. 4 points
    My first composite narrowband image. N44 is a massive HII region about 163 kly away in the Large Magellanic Cloud. It contains several notable deep space objects: emission nebulae (NGC 1934, 1935, 1936; IC 2218), and star clusters (NGC 1934, 1937). In the centre of the image you can see its main feature, a "superbubble" of expanding gas. The bubble was, apparently, formed by the radiative pressure from at least on OB-type star (LH-47). Please note that this is a false-colour image. H-alpha is rendered in red, OIII in blue-green, H-beta is in deep blue. Photo stuff: Luminance: 18 frames @ 240s ea. H-alpha: 10 frames @ 240s ea. (colour set to 656.28) OIII: 10 frames @ 240s ea. (colour set to 500.70) H-beta: 10 frames @ 240s ea. (colour set to 486.00) ISO 1600 Canon 60Da on RCX400 f/8 with a .7 focal reducer
  2. 3 points
    This is a follow-up to my previous image. The LMC will help you orient yourself. The N44 complex is the wee bit of blue and pink nebulosity to the right of centre, and, of course, the ever-impressive Tarantula Nebula (NGC 2070) is the big blue blob at the top of the image. Photo stuff: 96 frames @ 60s ea. ISO 1600 Canon 6D with a Tamron 500m f/8 cat lens
  3. 2 points


    This map shows the entrance to the building for tonight's meeting
  4. 2 points
    Southern pole finding is a challenge, as a newbie to this I gave up on visual methods and went to software. I start with a $15 compass to daylight align the stand to the pole, noting the world magnetic declination, for Chch magnetic south is roughly 24 degrees off polar south. Then a small level with a angular adjustment to get 43 degrees to roughly align Alt, basically need to be within 5 Degrees Alt/az for the software. Then when it gets dark I use Sharpcap ver2.9 http://www.sharpcap.co.uk/sharpcap/downloads The reason I use version 2.9 is the polar alignment is free in this version. Version 3 is yearly sub, small and annoying to pay like this, I'd pay a higher one off fee. anywhoo, off track, the alignment feature really helps and if you get the free version you can test camera and other setup requirements. Main trick is to get the right field of view, I use a ZWO ASI290 with a Orion 50mm guide scope, but I did do some calculations and one could use a 30mm guide scope with my camera. I believe a number of web cameras work in the software, really just a matter of getting FOV in the right range. Here is a short demo of sharpcap in action, northern polar alignment, but the software works in southern as well. https://astrobackyard.com/polar-alignment-in-sharpcap/ Software helped me, since my polar scope in my mount doesn't seem to work at all. regards
  5. 2 points
    Can't wait! Falcon Heavy launch window is open Wednesday 7:30am -10am New Zealand Time!!! Can't wait to see the most expensive way to dispose of an old car by sending it to Mars hahaha Give me hope we can one day get off this crazy rock :) (Sorry didn't know where else to put this. Didn't see an off topic forum. Hope it's ok. Cheers!)
  6. 2 points
    This one will burn up soon enough, and there's plenty of other bright satellites up there, like the ISS or iridium flares, and sigma stacking will remove them from photos, but we don't really want this kind of thing to catch on. Of course this comes hot on the heals of the failed and controversial Russian Mayak balloon satellite, which had no purpose other than for it's private backers to claim that they had the brightest star in the sky. Rocket lab will get some of the heat from that. Its not a new idea. Robert Goddard suggested using remote control pyrotechnic flashes and photography as a way of tracking satellites in the very early days. Echo 1 was a 30m NASA balloon satellite from 1960. In 2012 a small cubesat (FITSAT-1/Niwaka) had super bright LEDs which flashed out a message in morse code. Long exposure photos showed the message in the streak. Power limitations meant that it only operated at specific times, and of course it burnt up soon enough. However it does demonstrate the possibility of orbiting billboards!!!! This is the last thing anyone needs. Its great to see that these concerns have been raised so soon. Hopefully international satellite organisations will come up with rules governing this kind of thing. I suspect Peter Beck just wanted to be able to see his first rocket. After all, a larger rocket would be visible anyway, and his "star" will be gone long before many other large second stages. However the disco ball and name may be going a bit far! Space is getting cluttered, but at least cubesats address this by international agreement to only launch into orbits that decay fast. Cubesats are also too small to be seen unless they are deliberately illuminated or super reflective. Sputnik was highly polished for this reason. Most satellite light pollution is from the larger rockets and higher orbits. But we do need to maintain pressure to ensure that efforts are made to limit and reduce satellite pollution. For now it's still fun to chase these things :) Rob
  7. 1 point
    Astronomy Workshop Series for Beginners The Heathcote Valley Community Centre (HVCC) is glad to introduce the Astronomy Workshop Series for Beginners, a project designed to satisfy the curiosity of our small community. The first workshop is going to start on February 26th and there are still some places available, so we would like to make an open invitation to anyone keen to join us. The Rhythmic Sky – Astronomy Workshop by Erik Vermaat In this beginners course we are investigating how we see celestial objects move in the sky and why they move that way. This will change the way in which you see the sky, understanding the various rhythms that govern the firmament. THE RHYTHMIC SKY – 6 Week Workshop Mondays, 7.30 – 9.30 pm (120 min) 26 February – 2 April 2018 Price: $ 90 per six sessions Course description and enrollment information here: http://heathcotecommunitycentre.org.nz/2018/01/25/astronomy/ - Posted with the permission of CAS -
  8. 1 point
    Collimating a SCT. Most of us will look at this subject with horror (as did I). First reaction is “I don’t want to fiddle with it”. Second reaction is “my telescope is ok, why change it”. I had the same thoughts until some photos showed asymmetry and some chroma. I looked at all possibilities in an attempt at avoiding the subject of collimation. I finally had to bite the bullet and accept that collimation was in order. This document outlines the steps I took and hopefully demystifies the subject by offering some handy tips. It is not difficult to do. Firstly, check if the telescope is functioning well by focussing on a star. Sure – wind the focus out, rings look concentric don’t they? Well I found that this was difficult to assess due to poor seeing. Things dance around so much, it is hard to tell whether the rings are concentric or not. I accepted the “probably ok” mindset. First tip. You can check collimation in daylight in your lounge. Set the scope up horizontally and then look into it from the front and move slowly backwards. You will see shadow of secondary mirror surrounded by rings out to the circumference of the primary mirror. Line up the outline of the secondary with a rim of its shadow and look at the symmetry of the rings. This is best done with one eye, as parallax will confuse the pattern seen. If these look concentric you are at least reasonably collimated. You can actually use this method to collimate (by using a card with a pinhole to give reproduceable eye position) but I found the changes confusing and difficult to assess. This is however a good way to make a quick check. This will tell you if you have a problem or not. I had a problem! Next collimate using a star. The method here is well described in a great article by Thierry Legault. http://www.astrophoto.fr/collim.html This shows beautifully the patterns you are looking for and shows the difference good collimation can make. Best to look at this now before you continue. He describes 3 steps, each gaining more precision than the former. The process is as follows. Second tip: use a video camera. You can see real time changes and saves you from going from front to back to adjust and check results. The camera can be rotated so top of picture is 12 o’clock on the scope. (Left and right are transposed though). Chose a bright star as high in the sky as possible to reduce atmospheric effect as much as possible at a magnification about the diameter of your primary (magnification 200 for 200mm scope) Set focus (forward or backward until you see the shadow of the secondary near the middle of a set of diffraction rings. Check (and adjust as necessary) that the shadow of the secondary is central to the diffraction rings. If adjustment is necessary, you will have to turn one or two of the 3 adjustment screws in front of the secondary set at 120 degrees from each other. Third tip: use a pointer (I used a plastic knitting needle) in front of the scope to define a radius. This is easily seen, and you can orientate the pointer to the narrow or broad radius as desired. Making adjustments There are 3 screws. Adjustments should be slight (an eighth of a turn or less). If one screw is loosened, then the other two should be tightened the same amount. There should be equal tension on all 3 screws at all times. None should be loose. Beware of overtightening which can distort the mirror. Be careful when using a screwdriver pointing towards your corrector plate. I found that I needed to tighten in the direction of the narrowest band. If this is opposite a screw, tighten this one and back off the other two. If the narrowest radius is between two screws, tighten both and loosen the third. I can’t guarantee this is the direction for all telescopes but since it is trial and error, you will soon find out which direction to turn. The star will move as you adjust. You will have to re-centre it each time you make an adjustment. If the star goes out of the visual field completely you have probably made too big an adjustment. Because of the need to re-centre the star you will have to use the motors to re-centre the image. Don’t forget to set the mount for terrestrial use or the “star” will wander off. Second step is finer adjustment. Use a star of less magnitude and use magnification 2 or 3 times the diameter of the telescope. Focus back and forwards slightly looking at the concentric rings and the bright spot in the middle. Adjust as above to make it true. Third step is to put the star in focus and look at the Airey pattern. The star should be dead in the middle of the diffraction rings. Adjust (with smaller turns of the screwdriver) if necessary. I did all this and found that my collimation had indeed been off. However, it didn’t work! Due to seeing conditions, especially at higher magnification, I found it impossible to reliably centre everything. Fourth tip: Use an artificial star. I made one of these in an hour using parts from the workshop. I used a small utility box (available from Jaycar) a super bright LED from an old garden light fixed in place with hot glue and made a hole in a piece of heavy grade aluminium foil with a small needle. The hole should be the order of 0.2 mm diameter. I used a small needle (the sort you use for removing a splinter) and with some cardboard underneath, penetrated the foil part way up the taper of the needle. I suspect a cardboard box and a torch would do the job. The hole should be smaller rather than larger. For my 200mm SCT I placed it on a fence post at 50 metres (should be at least 25 times the focal length of the scope). Collimation was completed in 15 minutes! Your collimation should be pretty good by now. Good enough that you can wait till a great seeing night and chose a star for checking. PS. The artificial star was made from junk, so I can’t give an exact recipe for this. If there is interest enough I will make one from proprietary parts and publish construction details in another article. I suspect that there may in fact already be one of these at the observatory somewhere for members to use? Feel free to add comments and tips to this thread. Samples below are both 30 second exposures unguided using 500D SLR
  9. 1 point
    The Robin's Egg certainly doesn't look like your usual planetary nebula. The well-defined ring is nowhere in evidence, nor is the usual symmetry. However, the professionals have found that the nebula emits a fair amount of OIII radiation, which is typical of planetary nebulae. This, along with the bright central star (a double!), helped to confirm it as a PN. I may try imaging this one again but using an OIII filter sometime in the future. Unfortunately, that project will have to wait for a while. Fornax - the constellation in which the Egg resides - is setting much earlier now. This makes gathering good data a bit challenging with all the summer heat in the atmosphere. Next year... Photo stuff: 23 frames @ 300s ea. ISO 1600 Canon 60Da on the RCX400 16" f/8
  10. 1 point
    The Southland Astronomical Society wishes to inform the public of the passing of one of its founding members, Russell Beck, who died on Saturday 10th of February 2018. Russell was not only a founding member, but also life member of the Southland Astronomical Society. He was Director of the Southland Museum and Art Gallery in the 1980's -90's, which helped the society to mount exhibits of an astronomical nature. He built the 12” telescope which was housed in the museum's observatory. It went on to serve the community for four decades, until is was removed at Christmas 2015. Russell was involved in the establishment of the observatory and ran it for some years. Russell will be sadly missed and our thoughts and prayers go to the Beck family at this sad time.
  11. 1 point
    Thanks Grant, a very informative site.
  12. 1 point
    Ventusky - incredible cloud forecasts View File This has to be my favourite cloud forecast website. Its proved to be quite accurate with cloud cover over West Melton, Rolleston an Lincoln, confirming when one is clear and the other is not. Highly rated. Click on the map to get your location. Once you start to understand it, you'll also be able to see fog as opposed to cloud. Submitter Grant Submitted 01/17/2018 Category Useful Websites  
  13. 1 point
    Hi there - I'm thinking of purchasing a tracking mount for my astrophotography (probably an iOptron Skyguider Pro, but not finalised yet). However, I'm concerned about how difficult it is to polar align tracking mounts in the Southern Hemisphere. Are there any experts out there with tips/ideas - all the web posts I've seen have basically said "well, find sigma octanis and it's about there" but I don't know if that's accurate enough - how precise do you need to be for a tracking mount to work effectively I'll probably be shooting at 200mm at the longest focal length but also with my 24mm and 55mm lenses - I know the wider you go the more forgiving a misaligned mount is. Here's a shot from last night with me visually spotting the south celestial pole visually. Shot at 70mm with a 7 min exposure. It's close, but is this sort of accuracy good enough for a 90s 24mm or 55mm exposure, say? It was visually picked from the back garden in suburban Chch, so difficult to spot quite a dark constellation.
  14. 1 point
    There are a few ways, including visual which would provide enough accuracy for the focal you plan on using. After you get the mount you may drop at the obs and a few of us can show you the general procedure.
  15. 1 point
    Thanks Grant. I will pass this onto the senior students in my school's Space Club.
  16. 1 point
    An old version of the Millenium Falcon maybe
  17. 1 point
    Oh yeah! Up bright and early for that one :)
  18. 1 point
    The 31st Jan brings a lunar eclipse, and it remains in totality over Christchurch for 76 minutes Media attention is high as its being described as a blood moon super moon, but hey if it gets people interested.
  19. 1 point
    In Rolleston, thick cloud cover all night
  20. 1 point
    Great to see community interest in astronomy and thanks to Erik for helping
  21. 1 point
    If it is magnitude 7. whatever, it won't be that easy to see. Billboards sound horrifying. Hopefully I will see it before it burns up. I am pleased that it will eventually disappear. I don't like 'commercialisation' of space. We do enough damage to our planet with our rubbish, without cluttering up Space. International satellite organisations may make rules, but who will stop some egotistical individual from sending something up. Imagine a giant face of Donald Trump beaming down at us. YUK!!!!!!!!! I guess the only thing in our favour is that it will be extremely expensive to do so.
  22. 1 point
    Think I agree with you Euan, I don't think we need any more unwanted 'lights'. and, If I was into imaging, I would not be impressed about it.. Also, the thought of orbiting billboards mentioned from Rob, help NO!!!!!!! Interesting comments given...
  23. 1 point
    Its not actually that bright, so not sure if its working as intended. Its supposed to be naked eye, but no-one is going to see it based on these figures.
  24. 1 point
    In a significant astronomical discovery, School of Physical and Chemical Sciences at UC scientist Dr Anna McLeod has made the very first detection of a jet from a very young, massive star in a galaxy that is not our own. Marsden Fellow Dr Anna McLeod, of UC’s School of Physical and Chemical Sciences, says this discovery will drive significant advancement in the field of star formation. “It also gives a further clue on one of the biggest questions in modern astronomy: how do massive stars form?” Dr McLeod says. “Massive stars are so important because they regulate the formation of new generations of stars as well as the evolution of entire galaxies. Our discovery captures a massive star as it is forming, and it sheds light onto the formation mechanism.” http://www.canterbury.ac.nz/news/2018/new-nz-research-shows-first-jet-from-massive-young-star-detected-outside-our-galaxy.html
  25. 1 point
    Looks like they've had a bit of a backlash against their "disco ball". What are your thoughts? Personally I can't decide and probably won't until I see it. I think it would be fabulous for outreach and getting kids into space and astronomy and starting discussions, but I'm not sure I'd like it flashing across an aurorascape. That 9 months decay orbit may be a godsend.
  26. 1 point
  27. 1 point
    January 22nd 2007, what a night! Canon 300D, home-made sky tracker, taken from Thompsons Track. The glow in the lower part of the image is Ashburton. There was a howling nor-wester that night, and travel was ill-advised, according to the met service, but sometimes you just have to go.

    © Euan Mason

  28. 1 point
    The Rosette Nebula (also known as Caldwell 49) is a large spherical H II region (circular in appearance) located near one end of a giant molecular cloud in the Monoceros region of the Milky Way Galaxy. The open cluster NGC 2244 (Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formed from the nebula's matter. The cluster and nebula lie at a distance of some 5,000 light-years from Earth[3]) and measure roughly 130 light years in diameter. The radiation from the young stars excites the atoms in the nebula, causing them to emit radiation themselves producing the emission nebula we see. The mass of the nebula is estimated to be around 10,000 solar masses. The Rosette lies close to Orion and is a summer object - right now its high in the skies, sorry though this is one for the early hours. As its quite faint you need darkness, so last night was a late one starting around 2300 and cloud finally chasing me to bed at 0300! I managed an hour of good exposures inbetween high cloud and gusty NW winds. Still ... pretty pleased with what I captured - and chance to try out StarTools. This image was stacked in Astro Pixel Processor and post processed in StarTools. Taken on an ES102 FCD100 Refrac, Stellarvue 0.8 FF/FR, Moonlite focuser and Nikon D5300.
  29. 1 point
    The Seagull Nebula (IC 2177) is a very large nebula that sits ~3.7 kly away on the border of the Monoceros and Canis Minor constellations. Gum 1, pictured here, is the 'head' of the seagull, and I have to say that it looks a fair bit more frightening that most of the dozy birds I see on the seashore. The nebula is actually complex, being composed of both reflection (mainly blue) and HII emission (red) nebulae.The central star, V750 Monocerotis, is a yellow-white variable star thought to be part of a binary system.
  30. 1 point
    The Red Tarantula. Same object, different light source. What I'm finding with narrowband imaging is, Heinlein's words, TANSTAAFL: while you can gather data on moonlit nights, you pay for it by needing a lengthy amount of time for a decent exposure. At 3.5 hours, I'm barely there. The light is generated when an electron in a hydrogen atom drops a state (specifically, from n=3 to n=2). This happens a lot in emission nebulae like the Tarantula, so we get to see more of it in this light. Photo stuff: 70 subs @ 180s; ISO 1600; Canon 60Da on an RCX 16'' f/8 with a .67 focal reducer; Optolong 7nm H-alpha filter.

    © Gary Steel 2017

  31. 1 point
    The Blue Tarantula. I have been playing around with narrowband filters recently so I thought I would post an unusual take on a popular object. This is NGC 2070 in doubly-ionized oxygen (O-III) light. Imaging in narrowband light provides the scientist side of me with fascinating visual data about the structure of an emission nebula, and gives my artistic side another technique. As a bonus, it allows photography of certain objects even when the moon is up! Photo stuff: 50 subs @ 180s ea.; ISO 1600; Canon 60Da on an RCX400 16" f/8 with a .67 focal reducer.
  32. -1 points


    Due to the state of emergency issued by Christchurch City Council, and the data suggesting the weather is due peak at 10pm, I have been just been advised tonight's meeting has been cancelled. Selwyn has now also just issued a state of emergency.
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