NGC 2403

[Jedi2014]

Hi galaxy friends,

My latest image of NGC 2403 from the begining of february shows the galaxy quite nicely resolved and full of detail. The image became "image of the week" in the german astronomy website astronomie.de
They wrote a very informative text, which I like to share as well as the image itself:

While the galaxies M 81 and M 82 are very often photographed, NGC 2403 is more rare. NGC 2403 also belongs to the M81/82 group. North is at the top, east left with an image field of 42.5' x 34'. The spiral galaxy of the SAcd type is visually about 8.4 mag bright, its color is on average white-blueish. According to NED (NASA Extragalactic Database), NGC 2403 has an extension of 21.9' x 12.3' and a distance of 11 million light-years. At this distance, this results in a true diameter of about 70,000 ly. Here in the image, however, you can measure a slightly larger diameter of 23.7' along the longitudinal axis into the weakest outdoor areas, so that the true diameter of NGC 2403 is still around 6000 Lj larger.

The M81/82 group has an elongated shape, which roughly runs in west-east direction. All in all, it has about 60 member galaxies. The majority of these are low-mass dwarf galaxies, followed by larger group members, NGC 2403 in the western area and NGC 4236 in the eastern area. NGC 2403 is the "outpost" of the M81 group in the constellation of Camelopardalis. Its structure is characterized by a small core with coarse spiral arms. The image shows that these arms are interspersed with many bright star clouds, condensations and nebulous knots. Here a strong star formation takes place. In this relation and in dimension, NGC 2403 strongly resembles M 33, and NGC 2403 was the first galaxy outside the local group in which cepheids were found. These "standard candles" make it possible to determine the distance quite accurately.

Numerous H II regions in NGC 2403 already reveal amateur images, the brightest and largest of which even outdo 30 Doradus, the well-known tarantula nebula in the Great Magellanic Cloud. While it has a considerable diameter of 1300 Lj, NGC 2401-I, NGC 2403-II and NGC 2403-III have a diameter of 2000,1600 and another 1600 Lj (L. Drissen et al., 1999, Astronomical Journal 117,1249-1274). In these places of recent star formation massive stars were found. In addition to O-stars, numerous Wolf-Rayet stars could be detected which have a clear emission of helium (He II) at a wavelength of 465 nm and appear brighter in such filters than in normal blue filters. NGC 2403-I and NGC 2403-II also contain super star clusters very similar to the extremely dense super star cluster R136a in the Tarantula Nebula. Because of the massive stars, the superstar clusters are strong energy sources, by which the HII regions are highly ionized and also noticeably glow in [OIII]. This is also very similar in M 33.
 

Data and biger: http://www.spaceimages.de/en/astrophotos/galaxies/ngc-2403-galaxie
or https://www.astrobin.com/333312/

 

Greetings
Jens

[swag72]

Nice one Jens - You have done this extrememly well..... great processing, a very subtle style  

[Barry-Wilson]

The propcessing is not obvious and the natural result has produced a very good image - NGC2403 is prone to looking very granular and your image stands out having kept a harmonious look.  Well done Jens.

[gorann]

Beautiful and with a nice soft touch. Obviously your 16 hours of persistence and processing skills payed of (again).

[Tom OD]

Beautifully processed, very natural looking

Tom

[Petergoodhew]

That has to be the best NGC2403 I've seen Jens. You've managed to control those huge stars in front of the galaxy really well so that they no longer dominate it. Really impressive processing.

[Jedi2014]

Hi Sara, Barry, Göran, Tom and Peter,

thank you very much, your feedback is always appreciated.

Jens

[nucdoc]

Very nice, subtle look.  I like the almost fluffy look it has