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Thread: M77 through Jimi's 48 inch

  1. #1
    Member Howard B's Avatar
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    M77 through Jimi's 48 inch

    Last October, Steve G and myself spent several nights observing with Jimi through his 48 inch scope in Texas. They graciously gave me about 30 minutes each night to devote to sketching one object, M77. I built up my sketch over four nights, some better than others, and came up with the following drawing - which is re-drawn from my observing notes and eyepiece sketch.

    M77_second photo_crop_small.jpgM77_second photo_cropinvert_small.jpg

    My notes from each night:

    October 27, 2016
    "...There's a lot of motion, spiral motion, in the brightest areas around the brilliant stellar core and tomorrow I'll use more power to dive in and get the details more accurately placed. I used the 13mm Ethos (375x) tonight which also showed M77's outer halo. 21.50 SQM."

    October 27, 2016
    "Added to my sketch a few pages back, and with the increasingly steady seeing I could make out some internal details with the 8mm (609x) - until clouds murked out the view. No SQM because of the clouds."

    October 28, 2016 was cloudy all night

    October 29, 2016
    "Added lots of detail to my drawing using the 6mm Delos (812x) in the improved seeing. Wonderful! Used the 17mm Ethos (286x) for context but the 6mm view is a wonder. 21.67 SQM."

    October 30, 2016
    "Poor contrast and terrible seeing really make this a sucky view compared to last night - but I could still detect the connections to the outer ring. 286x, 21.36 SQM."

    It's taken me awhile to find time to re-draw my eyepiece sketch and process it well enough to present here. I'm not 100% happy with the final drawing - getting the outer ring at the right contrast has been a challenge - and if I come up with a better version later I'll post it here.

    Anyway, the best part of this whole thing is the two hours of observing and sketching time I had with M77 with Jimi's 48 inch. It was a great privilege to be given this much time on one object with such a magnificent instrument, and I give Jimi and Steve my sincere thanks for being so generous with their time for this project.
    Howard
    30-inch f/2.7 alt-az Newtonian
    https://sites.google.com/site/howardbanichhomepage/
    https://sites.google.com/site/sprays...pemirrors/home
    Contributing Editor, Sky & Telescope magazine

  2. #2
    Member Ivan Maly's Avatar
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    Love it; great observation and sketch, Howard. Here is mine from the same time (October). 20", 200, 300, and 450x, SQM 21.1. This was 2.5 hours, not counting the final drawing. The outer star clouds were not visibly connected as a ring, and no attempt was made to present them on the same brightness scale as the brilliant inner structure.

    Ivan
    20" Sky-Watcher
    deepskyblog.net

  3. #3
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    Impressive work Howard. Thanks for sharing this stunning result with us.
    Clear Skies, uwe
    http://www.deepsky-visuell.de
    Germany

    27" f/4,2

  4. #4
    Member Howard B's Avatar
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    Thanks Ivan and Uwe. As I mentioned I'm not completely happy with how the sketch is displayed above. The actual drawing shows the subtle details better so I'll give it another try soon.

    The view through the eyepiece was stunning, especially on October 29th, and it's always a challenge to faithfully capture such a view on paper, let alone get a good scan!
    Howard
    30-inch f/2.7 alt-az Newtonian
    https://sites.google.com/site/howardbanichhomepage/
    https://sites.google.com/site/sprays...pemirrors/home
    Contributing Editor, Sky & Telescope magazine

  5. #5
    Member akarsh's Avatar
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    Howard, the day I heard that you spent time on all 3 nights on M77, I wanted to see this sketch. The results are incredible!! I really like the knots in the core.

    Clear Skies!
    18" f/4.5 Obsession dob "Romela"
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  6. #6
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    Hi Howard,

    interesting result! Does the halo you´ve been talking about span about 2/3 of your sketch? Hard to see at my notebook... Really big halo then...!

    This January i spent some time too at this galaxy. Perhaps interesting what the object in 1/4 of your used diametre looks like :-)

    M 77_Schrift_northup.jpg

    The prominent dark inner ring that is clearly visible in your drawing was only subtle in my 12" at 170x. It didn´t appear like a ring at all - furthermore there were some dark patches right behind any brighter parts. Hard to describe. I tried to fix it in my sketch...
    However, the details surpised me enough to try a sketch - making it was not planned actually :-)

    NELM around fst 7m0. Mediocre Seeing.

    CS!
    Norman
    Last edited by Norman; March 22nd, 2017 at 05:48 PM.
    12" f/ 4,5 - tuned Sumerian Optics Dobson - Nauris main mirror
    - who stands the rain deserves the sun! -

  7. #7
    Member Howard B's Avatar
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    Hi Norman,

    Yes, the outer halo does span about 2/3 of the sketch - it is quite large. I haven't seen it in my 28 inch or any other scope, and my best sketch with the 28 inch is below as a comparison.

    M77.jpg M77_invert.jpg

    Hopefully the orientation is the same so the two sketches can be easily compared. This was from 2013 at the Oregon Star Party and was drawn at 467x. No SQM reading but probably in the 21.6 to 21.7 range.
    Attached Images Attached Images
    Howard
    30-inch f/2.7 alt-az Newtonian
    https://sites.google.com/site/howardbanichhomepage/
    https://sites.google.com/site/sprays...pemirrors/home
    Contributing Editor, Sky & Telescope magazine

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