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View Full Version : Object of the Week March 1, 2020 - NGC 2841



Dragan
March 2nd, 2020, 08:57 PM
NGC 2841
UGC 4966
PGC 26512

Galaxy

Type: SA(r)b
Mag: 9.1
Size: 8.1’ x 3.5’

Constellation: Ursa Major

Many new moons ago in May of 2015, regular OOTW author Mark Friedman did a wonderful job of inspiring observers to always give an object a chance, regardless of aperture and object magnitude. Mark was adamant to always ‘give it a go’ regardless of any preconceived notions. Later in his post, Mark elected to teach us about flocculent spiral galaxies and highlighted a beautiful galaxy as his own OOTW that week – NGC 3521 in Leo. (That post can be found here (http://www.deepskyforum.com/showthread.php?723-Object-of-the-Week-May-3-2015-NGC-3521-A-Flocculent-Galaxy&highlight=3521)) This week, I’d like to not just focus on another flocculent spiral, NGC 2841 in the Great Bear, but I’d like to remind readers to never pass up on an object because certain sources may influence them to not even try making an attempt.

Located near the border with Lynx in the Bears’ “toes” and lying approximately 46Mly distant, NGC 2841 is a massive 9th magnitude galaxy in UMa containing some 500 million solar masses. Discovered by William Herschel in 1788, NGC2841 spans 130,000 ly and is a ‘flocculent’ spiral that exhibits a prominent inner ring-like structure with patchy, disjointed spiral arms with no indications of containing a bar. Not to repeat Mark and his post, but comparing M33 to M51 is a good visualization to help illustrate a flocculent spiral (M33) to one that is not (M51).

Reminiscent to many of M31, NGC 2841 sits inclined to our line of sight, displaying a rather bright, bar-less core. Elongated NW to SE, the core brightens rapidly, nearly stellar in appearance. Observers have even noted spotting it from a dark site in 10x50 binoculars. Side note: NGC2841 is also the anchor galaxy for the NGC 2841 group, a small group of galaxies containing NGC 2681, 2541, 2500, 2552 and 2537 (de Vaucouleurs).

In closing, I’d like to reiterate a little bit of what Mark mentioned in his post. Please do not ever become intimidated by an object. The purpose of what we do here at DeepSkyForum is to help inform, educate and share all of our collective knowledge about the hobby we all love to do. I’m certain I speak for all visitors, registered and not, that visual observing is a life-long pursuit that only improves with practice and patience. It only advances our skill sets to push our limits as observers. Visual deep sky observing is unique in that no two nights are identical. We’ve all had those nights where seeing and transparency wouldn’t allow a decent view of M81 in a 30”. Then, some nights are so good, that it permits us to see something crazy like Mayall 2 in something like a 6” scope. You just never know.

Yes, DeepSkyForum really does focus on exactly what our name implies – deep sky objects. But don’t be dismayed. You never know what an object will reveal until you give it a shot. Sometimes it’ll be a faint, featureless shmutz. That’s part of the game we love. But other times, it may be the object of the evening. But you won’t know until you….

“give it a go and let us know!”

3808
©Adam Block/Mount Lemmon SkyCenter/University of Arizona

Raul Leon
March 3rd, 2020, 01:11 AM
Hi here's my observation from 4/4/2011: Ngc 2841 is a spiral galaxy in Ursa Major ; magnitude:9.2 ; size :8.1'x3.5' ; very large, elongated with a bright core; I used a 14mm Meade Ultrawide eyepiece at 113x magnification with my14.5 Starstructure Dob f/4.33809

KidOrion
March 3rd, 2020, 04:24 AM
My own single observation, from last year; I need to go back to this one with some heavier artillery.

03/30/19
DEXTER STATE PARK (parking lot) (43˚ 55′ 06″ N, 122˚ 48′ 48″ W)
MOON: 25 days old (20% illumination); rose at 5:10 AM
SEEING: 5
TRANSPARENCY: 5
SQM: not checked
NELM: 5.6
WEATHER CONDITIONS: temps in low 40s, breezy, not yet dewy; some visible patches of cirrus sweeping through
OTHERS PRESENT: none

All observations: 12.5″f/5 Discovery truss-tube Dobsonian, 14mm ES 82˚ eyepiece (112x, 0.7˚ TFOV) unless otherwise noted

10:08
NGC 2841 (UMa): A real gem! This is a highly-inclined spiral in UMa’s front foot. It’s 4.0’ x 0.75’, elongated NP-SF, with a long, diffuse halo that’s not super-well defined, a bright 0.5’ core, and a bright stellar nucleus. On the NP end of the halo is an embedded 11th-magnitude star; there’s another star embedded in the NP end, 1.25′ SF from the first, but this one is fainter at 13.5 magnitude. 1.75’ S slightly P the 11th-magnitude star is another 13.5-magnitude star. F the 11th-magnitude star by 6′ is the brightest in the field, which is 8.5 magnitude. S of the galaxy by 23′, just outside the field, is a superb double consisting of two 9th-magnitude components separated P-F by 0.3′ (the P-most of the pair is very slightly brighter). A fantastic galaxy!

wvreeven
March 3rd, 2020, 11:15 AM
A wonderfully positive and encouraging follow up on Mark's post, Dragan! My observations with my 20" from March 13, 2015, read:

At 151x visible as an elongated glow with a bright center. The northwest side is more sharply defined than the southeast side. To the northwest lies a star and to the northeast a star is superimposed on the galaxy. A dark lane is visible on the southeast side. At 320x the galaxy shows a very distinct S-shape, especially at the southwest side.

Bertrand Laville
March 3rd, 2020, 11:25 AM
Hi All,

Very interesting object, with a lot of dark lanes visible in my 25" obsession.
Here the report: http://www.deepsky-drawings.com/ngc-2841/dsdlang/fr

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

3810

Ivan Maly
March 3rd, 2020, 10:40 PM
Saw it in a 4-inch ten years ago (Bortle 3 site). Now, weather permitting, for the spiral structure...

Dragan
March 3rd, 2020, 11:53 PM
Bertrand, what a beautiful sketch!!!

Uwe Glahn
March 5th, 2020, 05:48 PM
Nice galaxy which is worth a more intensive visit.

I logged a quick test view with a new 20-inch. I noted: 20", 200x, NELM 6m5+; bright and large, NE side clearly harder bound, estimated fine structures shown as fine arms and thin dark lanes, very nice view

Uwe Glahn
May 1st, 2020, 09:25 PM
Finally also observed the fantastic galaxy. Could not resolve these fine details Bertrand did but could catch one dark lane at the SW side and two very difficult visible thin structures at the NE side.

sketch: 27", 419x, NELM 6m5+, Seeing II-III
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