Total Lunar Eclipse Event 27-28/9/2015 Andrew Thornett

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1 Total Lunar Eclipse Event 27-28/9/2015 Andrew Thornett Andrew Thornett, Peter Hill, Damian, David Dugmore, Ed Mann, and two new members of the group, Peter and son Andrew. Rosliston Forestry Centre, outside Barn Room. Lots of dew as night went on! Andrew and Damian bought their Orion 10 Dobsonian Telescopes. Andy also had his Skywatcher Equinox 120 Pro DS on HEQ5 Pro mount. Damian bought his Takahashi 102 on William Optics mount, with Nikon DSLR and Powermate (x2). David bought his 8 Skywatcher Dobsonian and also his binoculars to do sketching he bought along a comfortable seat very sensible! Ed Mann bought his EQ6 and 8 Celestron SCT on this mount he was taking pictures of the moon using a webcam on this. He also bought his 80mm Kson refractor on driven alt-az mount, and was using a webcam on this. Peter Hill was using his Canon 450D with 500mm telephoto. He also had an 8 Skywatcher on EQ5. The camera was tripod mounted using un-driven photo tripod. I started the evening off to a hilarious start after having most of the day desperately trying to remember everything I needed to bring, I then forgot to bring the Equinox telescope and had to drive back home to get it I did not realise I had not bought it

2 until I pulled out mount and set everything up and then thought that something was missing Good job I hadn t driven hours to a star camp!! The main event tonight was the total lunar eclipse of Earth s moon in Pisces, due to start around 1-10am, with maximum eclipse between 02:30-03:00. Above Damian s picture of early eclipse Peter first noticed a slight darkening at upper left edge of moon at 01:42. The moon had entered penumbra at 01:11 according to articles in various magazines and online sources but we did not notice it at that time. Even at 01:55, we could not observe the darkening in our telescopes but we could see it with naked eye, in 10x50 binoculars and in cameras attached to telescopes or cameras with zoom lenses. In the cameras, the darkening was really quite pronounced on live view, as it was by eye. By 01:57, the darkening of the side of the moon was very obvious by naked eye. Ring Nebula - Messier 57,Planetary Nebula in Lyra, 01:59. Misty sky and light pollution from moon at 01:30 meant M57 at this point was a faint fuzzy ring. Unimpressive even in the Equinox. When I added an OIII filter, contrast improved but still poor view. Excellent telescope so this was due to sky conditions at this time. Orion Nebula - Messier 42,Bright Nebula in Orion, 02:00. Low down. Four stars in trapezium. OIII filter improved contrast. OK view became spectacular later on in mideclipse.

3 Geoff Dryland s photo of Moon At 02:01, the moon had changed from bright and white before the onset of eclipse to a dark red colour. I would describe it as blood-red but I guess it depends on the colour of the blood! The following day I heard it described as copper-colour on the radio and it could be described that way too. One feature that particularly stood out was a narrow white strip at the moon s inferior pole that never quite disappeared, although changed from being at inferior pole to superior pole of moon after mid-eclipse. The moon progressively got darker so that Pete and Damian and Ed had to change their camera exposures during the event, and I also had to change exposure settings several times during evening on PD camera.

4 Roger Samworth picture of partial eclipse Pinwheel Galaxy - Messier 33, Spiral Galaxy in Triangulum, 03:46,Quite bright in both Dobs. Large irregular splodge. Likewise, M110 was quite bright. These observations using Paracorrs in the two Orion Dobs and 100 degree Ethos eyepieces in Damian s scope and Explore Scientific eyepieces in my scope. Venus, Planet in Leo, 03:49,Clear crescent, low in easy. Very bright. Orion Nebula - Messier 42,Bright Nebula in Orion, 03:50:21,Poor view before eclipse but spectacular with masses of detail although no colour in Dobs at mid-eclipse, particularly in the Dobs. In one spectacular view in Damian s dob, I could follow fine filaments of detail within the wings or M42 as they extended laterally from the trapezium. Four stars easily seen in the trapezium I debated with myself whether I could see a fifth star but even in the Equinox it wasn t clear, although I could probably just see the fifth star off edge of one of the others. Definitely could not see 6 th star. At 03:56,Damian could see five stars in the Great Square of Pegasus at mid-eclipse. The number of visible stars in the square is often used as measure of sky quality. I could only see two but then my eyesight is awful! The following information on measuring sky quality using the Great Square of Pegasus comes from The four stars that make up the square are (clockwise from NW corner): Scheat (β Peg) - mag Markab (α Peg) - mag Algenib (γ Peg) - mag Alpheratz (α And) - mag Limiting Magnitude Number of naked eye stars visible in the square Seeing Exceptional

5 Excellent 6 13 Superb Very good Good Above Average 5 4 Average Below Average Poor <= Very Poor

6 Messier 35,Open Cluster in Gemini, 03:58. M35 in Gemini is very obvious but its faint companion galaxy the football is much more difficult to observe. This is NGC2168. Very faint initially when we looked but as we continued to look at it, it weirdly appeared to get brighter and contrast appeared to increase relative to the background star fields. I went looking for IC2157, another faint open cluster near M35 but could not find it. The moon at 04:05 was now past mid eclipse. 04:23 would be the end of total eclipse. At 04:05, the moon now was really dark and red. The white margin had now moved around from the inferior pole to the superior pole.

7 At 04:09, the moon was clearly starting to brighten again, demonstrating that it was on its way towards the end of the eclipse. By 04:28, 5% of the moon was now bright and white again. Surprisingly, this was the point that I noticed some red colour in the PD camera for the first time. Looking back at my PD pictures later, I noticed that whether I can see a red or orange colouration or whether the moon appears grey depends on exposure length. This fits in with our experience during the event where the Dobs showed the red moon but the refractors did not, and the cameras only showed it with longer exposures. At 04:30, the camera exposures on DSLRs used by Pete and Damian were now down from 10 secs to 0.5 secs as moon was so much brighter. Lot of fog coming over. Number of visible stars rapidly diminishing and the Milky Way became invisible some time ago. During mid-eclipse we saw M33, M31, M32 and M110 easily and they were quite bright and obvious in the Dobs. We also observed the Christmas Tree Cluster, which is a gorgeous collection of stars definitely worth looking at! I found that our ability to see deep depended on which part of the sky we looked at. Moisture content was high and our equipment was soaking from the dew. The area around the zenith and the south were quite clear but my attempts to see M101 in the north were unsuccessful and few stars could be seen in the eyepiece. My overriding memories of this event will be the initial view of the moon as it entered eclipse, where it went black at one corner (rather than red), as if some disease was over-taking it (so I could easily understand the Chinese belief that lunar eclipse is a bad omen), the dim dark red moon at full eclipse (darker than ones I have seen previously), and the incredible way that the sky very rapidly became much darker with a much wider range of visible objects in the night sky once eclipse was full. The Orion Nebula was acted as a barometer of this change, ceasing to be dim and unimpressive to detailed and bright, and previously dim open clusters became bright in the eyepiece. The group of seven of us really enjoyed this evening and I was excited to have spent a full night observing has been some time since I last did this! I am also extremely grateful to Pete Hill, who helped me get my PD (Phil Dyer) video camera working so that I could get photos of the moon as it entered and during the eclipse. Andy