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View Full Version : OBJECT OF THE WEEK, APRIL 23, 2017: M106



RolandosCY
April 29th, 2017, 05:30 PM
Object Of The Week April 23, 2017---

M106 = NGC 4258

Canes Venatici

RA 12 19 00
DEC +47 18 00

MAG 8.3 V
Dimensions: 19 X 7 arcminutes

Type: SAB(s)bc


We deep sky astronomers belong to a rather crazy lot. We often go to the extremes trying to detect an extremely faint galaxy or a barely discernable nebula, and we often forget some of the wonderful objects that just beg for our attention. Such an object is the galaxy M106 in Canes Venatici.

M106 is a bright, large spiral galaxy, which is quite active and intensely studied by professional astronomers. The galaxy appears to have passed through some violent phases, its spiral arms appearing disrupted. A disk of gas and dust material appears to encircle the galaxy perpendicularly to the main spiral arms, while a black hole is possibly located at its center. Finally, a large (by extragalactic standards) amount of water molecules is also present in M106. A strange feature of M106, revealed in CHANDRA observatory photos, are the extra arms visible in x-ray and radio wavelengths that are not aligned with arms visible in optical wavelengths!

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M106 in composite (all wavelengths) and visible light http://chandra.harvard.edu/photo/2014/m106/

My own interest in M106 was somehow non-existent until very recently, when a friend observed it during a Messier Marathon and mentioned its nice appearance. At that moment I realized that the only thing I could remember about M106 was that it was a rather bright spiral in Canes Venatici, and my notes indicated that I had seen it in the past but apparently without really paying attention to it.

So, last week, after a major cold front that brought superb transparency and surprisingly steady seeing, I turned my 18” dob to Canes Venatici to see what M106 really looked like. Well, I was totally surprised to say the least. Instead of the typical roundish or elliptical patch of light, there was a big, bright, imposing galaxy with a high surface brightness. Even at low powers it was a commanding sight, and by applying magnification it just unveiled more and more.

The nuclear region was not the usual pinpoint of bright light, but it was distinctly elongated in a north-south direction, appearing as a bright beacon within the central area of this impressive galaxy. Surrounding this bright central region is a distinct ellipse of light, slowly fading away from the nucleus but quite sharply defined.

To the north and south of this central region, but within the confines of the ellipse, the vigilant observe will be mesmerized by this galaxy’s strange spiral arms. The southern arm appears as an extension of the central region, becoming though wider at its southern extremity, somewhat similar in appearance to a baseball bat, while a couple of very faint fuzzy patches are visible in the extreme southern edge of the galaxy’s outer halo. But it’s the northern arm that will leave the observer speechless. The northern arm departs from the central nuclear area, curves a bit to the east, and expands into a very bright wide arm, split in half and reminding someone of a dragon’s head with the mouth open, the western half appearing as the lower jaw. A distinctly darker patch appears right next to this “half-arm”, further adding drama to the scene.

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M106 as seen with an 18" dob.

I also observed M106 with my 4” apochromatic refractor. Obviously, much less detail could be seen, though both the main north and south arms were faintly detectable within the outer halo of the galaxy. And M106 is also a nice binocular subject: I did spot easily with direct vision in my 15X70 binoculars as a rather bright elliptical patch, sort of similar to M81.

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M106 through a 4" refractor.

So, next time you are out in these nice spring evenings, remember to turn your scopes to the splendidly beautiful M106, and…

GIVE IT A GO AND LET US KNOW!!!

Ivan Maly
April 29th, 2017, 06:40 PM
One of the easiest galaxies to see arms in, although they are not especially spiral. Noticed already by W. Herschel - he called them "branches". Also there is some surprisingly sharp dust detail in the Magellanic companion. I need to reobserve this pair, but for now this is the old sketch (16", 75-225x).

https://4.bp.blogspot.com/-3HXGgZUIL3c/Td22CF2zFtI/AAAAAAAAABg/5IXfh0GABcY/s1600/M106+Page+6+800x640+%D0%BA%D0%BE%D0%BF%D0%B8%D1%8F .jpg

Howard B
May 3rd, 2017, 12:22 AM
Great object Ivan, and yet to my surprise I have only a tiny sketch of M 106 as it relates to the nearby galaxy group. I think it will be one of my first targets to sketch this spring!

Uwe Glahn
May 5th, 2017, 08:30 PM
Nice object and wonderful sketch Rolandos.

M 106 is indeed worth a visit. Not only because of the inner structures but because the outer fainter arms and the companion galaxies.
16", 180x-257x, NELM 6m5+, seeing II-III
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For those with very large aperture >30", better >40" both aligned discordant redshift quasars could be an interesting target. Both objects are around 20mag, so no classic messier marathon object.
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