Galaxy NGC 2336

NGC 2336 is a spiral galaxy. Spiral galaxies consist of central regions called bulges and several spiral arms. Besides spiral galaxies there are other types of galaxies like elliptical galaxies or lenticular galaxies. The formation and evolution of galaxies are studied at the Astronomical Institute of the Ruhr-University Bochum. 

How far the galaxy is from us is only vaguely known, astronomers estimate that it could be up to 100 million light years. If we assume that this distance is correct, galaxy NGC 2336, with a diameter of 200,000 light-years, is twice as large as our own galaxy, the Milky Way.

To explain:

A light year is the distance that light can travel in the vacuum of space within one year. Since light travels at a speed of about 299,792,458 meters per second, one light year is equivalent to about 9.46 trillion kilometers.

The concept of the light year is often used to measure distances in space because the distances in space are often so great that conventional units of measurement such as kilometers or miles are not sufficient. For example, the distance to the nearest star system, Alpha Centauri, is about 4.37 light-years. This means that the light we see today from Alpha Centauri was emitted 4.37 years ago.

So, with a distance of 100 million light years, Galaxy 2336 is very far away.

Yes, with a telescope you can find the galaxy in the constellation Giraffe by yourself. However, you have to know exactly what you are looking for, because with an angular extent of 6.5 x 3.5 arc minutes, the galaxy is about 30 times smaller than the full moon.

To explain:

An arc minute is a unit of measurement used in astronomy and geodesy to measure angles. An arc minute is the 60th part of a degree, which means that a full circle has 360 degrees or 21,600 arc minutes.

A minute of arc is often abbreviated with the symbol ' (an apostrophe). For example, an angle of 1 degree and 30 minutes of arc (1° 30′) corresponds to an angle of 1.5 degrees or 90 minutes of arc (1.5° or 90').

Arc minutes are often used to measure the apparent diameter of celestial objects or the distance between them in the sky. For example, the full moon has an apparent diameter of about 30 minutes of arc.

The image is a color composite, which means that different color images of the galaxy have been put together. In the case of the galaxy NGC 2336 the American Judy Smith took color images in red, green and blue. The images were taken in January 2020 by the Advanced Camera for Surveys (ACS) of the Hubble Space Telescope (HST).

In the different regions of the galaxy NGC 2336 different colors can be seen: the blue color of the spiral structure is caused by hot, and therefore blue, young stars while the yellowish central part consists of older, cooler (and therefore redder) stars. The blue, young stars have been formed in the last about 20 million years from the interstellar gas in the spiral arms. For comparison: our sun is about 5 billion years old.

So the colors of the galaxy say something about the composition and age of the different regions.

The name "NGC 2336" is a catalog number and stands for object 2336 in the "New General Catalogue of Nebulae and Star Clusters". The catalog lists the non-stellar objects in the sky unknown in 1888.

To explain:

"Non-stellar" means "non-starlike" and in astronomy refers to objects or phenomena that are not associated with stars. In addition to galaxies, this also includes cosmic rays, for example.

In the center of the galaxy, a very massive central black hole of 30 million solar masses was detected. The black hole in the center of our Milky Way is comparatively small with about 4 million solar masses.

Yes, just like our Milky Way, the galaxy NGC 2336 is in constant motion and at a very high speed. The motion conditions in spiral galaxies like NGC 2336 triggered the search in the 1970s for so-called dark matter, which astronomers know must be there even if it is not visible and does not respond to light or radiation. The large-scale distribution of dark matter in the universe is also studied at the Astronomical Institute of the Ruhr-Universität.