Object Of The Week December 8, 2019 - M 77

[wvreeven]

M 77, NGC 1068, UGC 2188, 3C 71

Seyfert 2 Galaxy

Constellation: Cetus

RA: 02 42 40.771
DEC: -00 00 47.84

Visual magnitude: 8.87
Dimensions: 6.92' x 6.03'

This is one of the Messier objects that wasn't discovered by Messier himself but, in this case, by Pierre Méchain in 1780. Apparently both Messier and William Herschel described this object as a star cluster but of course nowadays we know this to be a galaxy. As a matter of fact, it is a Seyfert galaxy of type 2. Again, background on Seyfert galaxies can be found in an earlier OOTW article of mine (http://www.deepskyforum.com/showthread.php?1137-Object-Of-The-Week-March-10-2018-NGC-3147).

Here is a stunning picture taken by Adam Block:

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Visually this galaxy was classified several times as a non-barred spiral galaxy that shows several ring-like structures. However, infrared observations do show a prominent bar and that's why Wikipedia (https://en.wikipedia.org/wiki/Messier_77) claims that it is classified as a barred spiral now. However, Simbad (http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=m+77&submit=SIMBAD+search) mentions nothing related to bars in the classifications of this galaxy. Simbad does however classify this galaxy as an AGN, an X-ray source, a gamma ray source, a variable source and also as a galaxy in a pair of galaxies. Unfortunately Simbad doesn't really state which is the other galaxy in the pair but there turns out to be an NGC 1068 Group (http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NAME+M77+Group&NbIdent=query_hlinks&Coord=02+42+40.7-00+00+48&children=8&submit=children&hlinksdisplay=h_all).

M 77 is notoriously difficult for beginning observers. The fact that it is in the Messier list gives it a false pretense to be an easy object but due to its Seyfert nature this is far from true. This galaxy requires a dark sky for anything more to be visible than its core and when observed from less than optimal conditions this makes it a very unimpressive object.

However, observed from a very dark location with a reasonably big telescope reveals a stunning spiral galaxy. My own observing notes from over 9 years ago with my 20” telescope from a dark location read

“At 160x a bright core with a faint halo. Spiral arms are visible in the faint halo. Very impressive!”

Not much more was logged by me. I wonder what you have made of this beautiful galaxy and if anyone has been able to identify any of the knots in the arms or the faint outer ring.


As always,

"Give it a go and let us know!
Good luck and great viewing!"

[wvreeven]

And yesterday this stunning image revealing the magnetic field of M 77 was published:

https://www.nasa.gov/feature/how-to-shape-a-spiral-galaxy

[Ivan Maly]

Great choice, Wouter. This is one of my favorite galaxies. Below is a sketch I made at our club's observatory three years ago. 20" F/5. Transparency above average, excellent seeing. SQM 21.1. 13-mm Ethos for the outer star clouds and main features of the core. Fine features of the core: 8-mm Ethos. Innermost ring: 5.5-mm ES100. "E" (my abbreviation) are HII regions from the Evans-Koratkar-Storchi 1996 catalog. The star clouds outside of the marked regions are in the area of the outer ring, which was not seen as continuous. They are fainter relative to the core area than the sketch might suggest - the brightness variation among the features in this galaxy is enormous, and I did not attempt to reproduce it on one scale. One of the SDSS galaxies in the field has a redshift distance of 1.8 Gly. This must be the farthest galaxy I have seen as definitely nonstellar, although I don't keep a list of them. In the sketch, N is up.

https://2.bp.blogspot.com/-gEccrD_hglY/V_7gnfGd62I/AAAAAAAAB0o/PR3gtmQ9WMg046fZZlnVlQZsr2c90xJwgCLcB/s320/M77%2B2016-10-10%2Blabeled%2B2.jpg

[Raul Leon]

Hi,
Here's my observation from 11/17/2017: Messier 77 spiral galaxy in Cetus; magnitude:9 ; large; bright halo with a bright stellar central nucleus ; I used a 6mm Ethos at 264x with my 14.5 Starstructure Dob f/4.33728

[Bertrand Laville]

Hi All,

M 77 is undoubtedly a stunning galaxy if you are lucky to observe it in a very dark sky, and a bis scope.
Here are somme sketchs, made with a 20" in a Namibian sky, and a 25" in Southern Alps.

Clear skies
Bertrand
http://www.deepsky-drawings.com


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http://www.deepsky-drawings.com/m77-t508/dsdlang/fr
http://www.deepsky-drawings.com/m-077-ngc-1055/dsdlang/fr

[wvreeven]

Very nice sketches on your website Bertrand! Unfortunately the attachments don't work for me.

[Bertrand Laville]

Sorry,
here are they

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[Bertrand Laville]

and sorry for the second time !!!

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[Howard B]

I had the delightful experience of observing M77 with Jimi's 48-inch scope for a total of two hours spread over four nights a few years ago. There is so much detail in the brightest part of the inner galaxy, and the soft outer ring is is nearly as ephemeral as the outer reaches of M87, and together are simply a beautiful sight.

I didn't realize that M77 was a type 2 Seyfert before observing it, and so wasn't expecting to see anything related to an AGN. This is an excerpt from my November 2018 S&T article:

"The AGN’s 51-degree tilt to our line of sight effectively hides it from our direct view though. Buried somewhere in there is the 15 million solar mass super massive black hole that makes M77 a Type II Seyfert galaxy. It puts out enough radio energy to be listed as 3C 71, and enough x-rays to be cataloged as Cetus A. Makes me wonder how M77 would be classified if its AGN jet was pointed right at us.

The direction of the short spray of material that’s connected to the star-like point is aligned with the stream of x-rays beaming from the AGN, as seen by the Chandra X-Ray Observatory. Even though I didn’t draw it at exactly the same angle – it’s pointed a bit west of north in my drawing rather a bit east of north as shown in the photos - I’m tempted to think I saw the visual manifestation of the AGN beam. It’s certainly in the right place and pointed in nearly the right direction. The thought that I might have seen a bit of M77’s AGN outflow gives me a delightful case of goose bumps."

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Here's the caption for the sketch with numbers and lines:

"HII regions seen in the central spiral arms of M77 with Jimi Lowrey’s 48-inch telescope. No filters were used, and the numbers are from the EKS 96 HII catalog (EVANS I.N., KORATKAR A.P., STORCHI-BERGMANN T., KIRKPATRICK H., HECKMAN T.M. and WILSON A.S. http://adsabs.harvard.edu/doi/10.1086/192308). Note that 079, 080, 084 and 065 are almost equally spaced and in a straight line with the AGN."

Caption for the positive image sketch:

"This is my finished pencil drawing of M77 as seen through Jimi Lowrey’s 48-inch telescope over four nights and a combined 2 hours of observing from his West Texas observatory. Magnifications from 286x to 812x were used. Sky Quality Meter (SQM) readings ranged from 21.36 to 21.67 during the four nights of observing. North is up."

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Both the HST image and the Chandra/HST composite show the AGN outflow that lines up fairly well with my sketch.

Finally, I didn't notice the two background galaxies Ivan saw, and even though I wasn't looking them they didn't jump out either - so something to go looking for next time!

[Uwe Glahn]

Wow, nice results here. And incredible sketch Howard, such inner detail together with the faint outer ring is rarely shown.

My experience with M 77 started with a simple 8x30 binocular, where the galaxy is visible as a faint glow. With my old 16-inch I used a steady night to study the innermost part of the galaxy. With the given EP the outer ring was not visible.

sketch: 16", 450x, NELM 6m5+
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[ScottH]

9/27/22 Messier 77. Using the 16” and then the 10”, was able to confirm my hunch from last winter that the (probable) super-star cluster inside the H-II/SFR known as [EKS96] 023 is visible in my 10” at 260x (stellar, of course!).

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Scott