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Thread: Object of the Week, March 30 2014 – VV 788

  1. #1
    Member Howard B's Avatar
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    Object of the Week, March 30 2014 – VV 788

    VV 788

    Ring Galaxy
    Draco
    RA 12h 32m 5.2s
    DEC +66 24’ 10”

    Size 0.5’
    Magnitude 15.8

    VV788_SDSS image.jpg

    Located about halfway between the Big and Little Dippers is the faint ring galaxy, VV 788 and its three companions. I have two observations of this fascinating object, one each with my 28 inch and Jimi’s 48 inch.

    VV 788 is the blue ring galaxy with the small, off center yellow core just inside its top right edge as seen in the SDSS image here. This is quite similar to the Cartwheel Galaxy (ESO 350-40) and Hoag’s Object (PGC 54559).

    The SDSS DR 9 navigate tool says the off-center core of VV 788 has a magnitude of approximately 16.4 while Megastar shows 15.8, which is presumably the integrated magnitude of the entire object. That’s just a guess on my part though. Regardless, VV 788’s overall blue color suggests it’s much closer to us than its three companion galaxies.

    With my 28 inch I first found NGC 4513, a 14.0 magnitude galaxy that’s only about 4 arc minutes away from VV 788, and then scanned over to VV 788’s position:

    “Interesting! I found VV 788 with averted vision but only as a vague blur without any structure. The soft seeing doesn't help but VV 788’s faintness is the main difficulty with seeing its shape. Even so this is worth a good look during steadier seeing. 408x, 21.39 SQM.”

    N4513_VV788_crop.jpg N4513_VV788_cropinvert.jpg Megastar VV788 DSS image.jpg

    The view in Jimi’s 48 inch was, not surprisingly, much more interesting:

    “Now that’s a ring galaxy! The right side (west) looks “knotty” and is brighter than the left side of the ring. The small, faint galaxy nearest the ring is 18th magnitude (according to Megastar). 660x, 21.61 SQM.”

    VV788_crop48.jpg VV788_crop48invert.jpg

    The SDSS DR 9 navigate tool shows the galaxy MAC 1232+6624, the one that appears closest to VV 788, is actually around magnitude 16.25, which makes sense since I was able to see it without much trouble in my 28 inch scope.

    I didn't see the core of VV 788 as a separate object but I wasn't looking for it in Jimi’s 48 inch. I’ll bet on a good night it would be visible as a small knot on the inside of the ring though. For all that, it might even be visible on a great night with my 28 inch. Time will tell, but I’ll certainly keep VV 788 near the top of my “observe again” list.

    "GIVE IT A GO AND LET US KNOW"
    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 FaintFuzzies's Avatar
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    Great object! If you haven't gone for it, give it a shot. This is an easier ring galaxy to see than Hoag's Object, it least it was for me.

    I've seen this object several times in 2010 through Jimi's 48" and my 22" reflectors.

    Below are the notes

    (http://www.faintfuzzies.com/OR-May2010-Lowrey48.html)
    48” (813x) – The ring was uneven. The west side was brighter and knotty. The east side was slightly dimmer with two “missing” parts. Actually the missing parts are much dimmer than the rest of the ring. Three other galaxies to the east of the ring were easily detected. CGCG 315-44, the middle one was the brightest of the three, followed by CGCG 315-43. MAC 1232+6624 was the dimmest and smallest.


    I wanted to check this thing out in my 22" and it was a pretty good night at Blue Canyon, so I gave it a shot and resulted in the following notes:
    22” at 306, 383 and 460x – This is one of my favorite ring galaxy groups. The ring galaxy, CGCG 315-43, is a faint even surface brightness glow with hints of brightening at the edges suggesting a ring. Two of three companions detected as very faint glows. The first companion, CGCG 315-44, is round and very faint. 0.2’ across. The other one, CGCG 315-43, is a 2:1 elongated glow. PA = 120 and 0.3’ long.
    Other nearby galaxies: NGC 4513 is a considerably bright 3:2 elongated glow with a much brighter center. PA = 15 and 0.6’ across. MAC 1231+6622 is extremely faint round glow. 0.1’ across. MAC 1231+6625 is a very faint round glow, also 0.1’ across.
    (http://www.faintfuzzies.com/OR-Jun122010-BC.html)

    There is a thread here as well. http://www.deepskyforum.com/showthre...ot-ring-galaxy
    Clear skies,
    Alvin #26
    faintfuzzies.com

  3. #3
    Member Howard B's Avatar
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    Dang, I missed that 2012 thread! Hopefully some other folks have observed VV 788 since then and can add their observations.

    Howard
    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

  4. #4
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    Howard,

    no worries, the object is cool enough to mentioned several times. I throw in my sketch again:

    27", 586x, NELM 6m5+, Seeing II
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    http://www.deepsky-visuell.de
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    27" f/4,2

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