PDA

View Full Version : Object of the Week, February 10, 2019 - Rosette Nebula + Cluster, in MONOCEROS



Paul Alsing
February 10th, 2019, 10:39 PM
Object of the Week - NGC 2237-9, 2246 + NGC 2244, Rosette Nebula + Cluster, in MONOCERUS
R.A.: 06h32m02.0s Dec.: +04°59'10" (2000)
Apparent Size: 70.0'x 60.0'
Magnitude: 5.50

I found it hard to believe that the Rosette Nebula had never before been featured as the Object of the Week, so I jumped at the chance to highlight this wonderful assembly of objects. The Rosette Nebula itself, about 5000 light years distant, is made up of NGCs 2237 and 2246 (discovered by Swift), NGC 2238 (discovered by Marth), and NGC 2237 (discovered by John Herschel)… and the beautiful open star cluster in the center, NGC 2244, was discovered by John Flamsteed, in 1690. The NGC 2237 designation in modern times is usually used to describe the entire nebula, just to keep things simple.

At over one degree in diameter, the Rosette Nebula covers about 5 times the area of our moon, so visibly this is a huge object. Not surprisingly, it can’t be seen in its entirety by most large light-buckets, but it is sure fun to “fly around” observing smaller elements, especially when employing a filter of some kind, and in my experience all of the various deep sky filters work pretty well to bring out subtle and not so subtle details. Smaller telescopes can see the whole nebula in the same field of view, but a fairly dark sky is required and smaller telescopes might be restricted to using a wider passband filter, like the UHC/LPR types.

The Rosette Nebula is a perfect example of a stellar nursery, much like the Eta Carina, Orion, Lagoon, Eagle, and Swan Nebulae, and there are hundreds of others, and they come in all shapes and sizes. We can even see these emission nebulae in other galaxies, and the best known of those might be NGC 604, which is within M 33, a local group galaxy just down the road about 2.7 million light-years away. NGC 604 is one of the biggest HII areas known. The Great Orion Nebula, M 42, is about 1500 light-years away and NGC 604 is about 1500 light-years across, which makes it about 100 times larger than M 42! Think about that for a while and try to wrap your head around it. These stellar nurseries all work pretty much the same way, a large interstellar cloud of gas collapses, stars begin to form in a central cluster, the radiation from the cluster clears a “hole” in the center and lights up the rest of the cloud… and we get to enjoy ourselves for hours on end checking out the whorls of clouds and the dark lanes and the Bok Globules to our heart’s content. I find it to be an amazing adventure when the conditions are favorable and the sky is dark.

Obviously, the Rosette Nebula is very popular with our brothers over on the dark side, the astrophotographers. I know this because the Rosette has been featured on the APOD 27 times since its inception about 24 years ago, averaging more than once a year. Here is a list…

https://apod.nasa.gov/cgi-bin/apod/apod_search?tquery=rosette

If I were an astrophotographer I would make the Rosette Nebula a top priority, too, it makes for an amazing photograph…

https://apod.nasa.gov/apod/image/0702/rosette_gendler.jpg

I had to post a link instead of a photo because this DeepSkyForum interface is not working properly right now... Dragan will take a look at it at his earliest convenience :idontknow:

As always, give it a go and let us know.

Paul Alsing
February 10th, 2019, 10:49 PM
Well, DeepSkyForum is very frustrating for me today, first I can't insert a picture and now I can't edit my incorrect spelling of "Monoceros"... I guess it's just not my day :angry:

Dragan
February 11th, 2019, 05:26 AM
Paul,

I was able to edit your typo in the title but not in the body. I'm having the same problem as you. I was able to add a photo as a test. See below.

But while I'm here, I may as well as submit an OR. Regrettably, we are sitting in LAX right now on our way home from Hawaii. Got to spend a week observing with Dave Kriege and one of his 22" UCs on Mauna Kea at two different sites of 9200ft and 5300ft elevations. Needless to say, we had a great time.

We observed the Rosette this past Friday night from the 5300ft site on a night with excellent transparency but average seeing. Using a 21Ethos we were both able to note bok globules along the inner perimeter and central area of the nebula. And of course, as you noted, we could only take in the entire nebula by segments. There was no chance seeing the nebula in its entirety.

Here's an unedited raw pic from our last night observing just before tearing down. Boy did I have a great time. It was long overdue as I have not had any serious observing sessions in a very long time.

3434

wvreeven
February 11th, 2019, 08:17 AM
Great choice and indeed incredible that this fine nebula hasn't been OOTW yet. I have seen the nebula with telescopes of various sizes and even with the naked eye! I was in Madagascar in January at 24 degrees latitude south and the Rosetta Nebula passed overhead. It was easily visible as a round glow around NGC 2244. Two weeks ago in La Palma I was able to see it with 10x50 binoculars. And since I am an astro photographer as well and would like to help test the forum software, I'm adding my pic of the nebula taken at La Palma with my 71 mm WilliamOptics ZS telescope and modified Canon EOS 700D DSLR camera ;)

3435

Bertrand Laville
February 12th, 2019, 02:39 PM
Hi All,

Here is two drawing of NGC 2237 and 2238, the densest parts of the nebula, specially the globules and dark veins.
for 2237: http://www.deepsky-drawings.com/ngc-2237/dsdlang/fr
and for 2238: http://www.deepsky-drawings.com/ngc-2238/dsdlang/fr

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

3436

3437

Uwe Glahn
February 24th, 2019, 08:00 PM
I also could catch the Rosette with naked eye and two [OIII] filters. The glow was not to difficult when transparency was good.

With 4-inch the object started to be structured. For me the view was always disappointed, maybe because of the knowledge of views with larger apertures?
sketch: 4", 18x-26x, [OIII] NELM 6m5+
3445

Best views of the nebula was always with apertures of around 10-inch. The objects fill the field with some space around and gives lots of structures. My favorite impression.

Years ago I spend two nights and lots of hours under the sky of Morocco with an 16-inch and tried to catch as much detail I could reach. Of course a stunning view, but I stick to my impression with 10-inchers.
sketch: 16", 59x, [OIII] NELM 7m0+
3446