Recently Browsing 0 members
No registered users viewing this page.
POLAR ALIGNMENT IF THE POLE STAR IS OBSTRUCTED (e.g. OBSERVING ON A S-FACING BALCONY!!!) Set up your scope on the floor (assuming it's reasonably level) in equatorial mode, with a rough guess at North. Put the tube into whatever 'home' position the instructions specify, or that you have chosen. Now choose an easily recognisable bright star at mid altitude. Pretend you HAVE polar aligned, and tell the scope to go to this star. When the slewing stops lift the scope very gently and turn the mount round till the star is in the centre of the field of view and you should have a fairly good polar alignment. If you are for example videoing planets and can also autoguide, this alignment may be all you need. But you can now refine it by the drift method if you need to - see https://www.skyandtelescope.com/astronomy-resources/accurate-polar-alignment/ This method should be quite useful for Southern hemisphere observing, where the 'south pole star' - Sigma Octantis - is difficult to find especially in light polluted skies. And of course my advice here applies if you have a North-facing balcony!
Well, I was finally able to put the newly repaired Sphinx through its paces over the weekend, Saturday night turned out a bit of a bust weather wise, however it gave me the advantage of already being set up for the following evening which was a completely different story.
Sunday...? Transparency not all that great, (perhaps NELM variable 3 to 5) and with a half moon shining, not ideal conditions for deep sky observing, however was still able to bag a few old favourites, including M53, M13, M92 and M51, M81 & 82. Then spent the next two hours exploring some galaxies in Canes Venatici, Coma And Virgo. Managed to pick up M63 - The Sunflower Galaxy, NGC 4565 - The Needle Galaxy, M64 - The Blackeye Galaxy, M104 - The Sombrero Galaxy, NGC 4631 - The Whale Galaxy, NGC 4559, M84 and M86 from Markarians Chain, The Leo Triplet and M87 - Virgo A, plus a whole host of other NGCs. Not much in the way of detail, (mainly due to variable conditions), they pretty much all lived up to their names as ‘faint fuzzies’, but nonetheless a most rewarding couple of hours. The Sphinx performed spectacularly, with each goto resulting in the target well within the FOV. The most gratifying aspect of the evening was the integration of the Avalon X-Guider into the ensemble, getting the main scope and finder dialled in is just so much easier now. Also the laser pointer performed its function perfectly as well, that being to improve efficiency of initial star alignment. All in all a most enjoyable two hours or so of observing.
Date: 2018 03 25 22:00 to 00:00
NELM: Variable 3 to 5
Seeing: II Antoniadi
Restrictions: 1/2 Moon to SW
Scope: C8 EdgeHD with modified longer focal length due to 2” Crayford and Diagonal.
FL: Approx 3200mm
Eyepiece: 22mm T4 Nagler:
Mag: 3200/22 = 145
AFOV: 82 Deg
Exit Pupil: 22/16 = 1.3mm
So, I’ve set the scope out in the garage to cool but now I’m trying to weigh up the pros and cons of observing tonight.
Pro - It’s the last clear spell forecast here for a week so I might regret not taking the chance.
Con - Its -3 already and only going down from here.
Pro - The seeing was great last night. Spent a couple of hours on the moon at over 450x! Very stable and detailed so it decided to max out by barlowing my 3.2mm BST to give over 700 for a test and although that was less detailed it was still acceptable, so wouldn’t want to miss conditions like that again.
Con - Moon is very full now so perhaps a little less to interest me.
Pro - I’d have managed 11 nights this month which ties with my best for a February.
Con - Work again tomorrow and I’ve been a little tired all day from last night.
So a bit of a tie so far. Anyone else in a quandary tonight?
i was wondering how many of you do sketching? I’ve tried to find some sites to help me get an idea on how it can be done but slightly struggling. For example what type of pencils and paper are preferred is it better to draw on black paper or white? I won’t have goto on my Mount when my scope comes so not sure if it will make it harder without one.Obviously I need a red torch as well. Would like to get some good sketches of the moon and clusters first and then galaxies/nebula and spend a good amount of time on sketching an object. If you have any tips It would be much appreciated also if possible would like to see some samples of sketches that you’ve done