One of the gems of autumn and winter nights is the Andromeda Galaxy (Messier 31). This is the closest bigger galaxy to us, after the dwarf galaxies orbiting the Milky Way System. It is 2.5 million lightyears away from us, its diameter is 180,000 light-years. The galaxy, with a solar mass of 370 billion, includes twice as many stars as our Milky Way (which contains 200-400 billion). The area of the Andromeda Galaxy that we can see in the sky equals the diameter of six full-moons, but the dim part can be detected only photographically. Its apparent magnitude is 3.4.
An interesting fact is that the galaxy is approaching us with a velocity of 110 km/s. Consequently, in about 4 billion years, our galaxies will collide. As a result, the Milky Way and the Andromeda shall unite. This future galaxy already has a nickname: Milkomeda
On the picture, we can detect two large satellites of the Andromeda Galaxy, named M32 and M110. Beyond that, you can see many smaller, interesting objects. Such as the NGC 206 star cloud. Furthermore, the marked objects can be worth of interest as well. The green, PGC-signed, “small, stretched stars” are galaxies, in fact. The objects with a Bol sign are globular clusters containing hundred thousands of stars and are found in the vicinity of the Andromeda Galaxy. The 2MASS J00425126+4106099 is an orbital body, emitting strong X-ray-radiation. The LGGS J004137.93+410107.9 is a quasar of 19.8 apparent magnitude. Its light hardly can be detected on my photograph.
I faced a lot of difficulties during the making of the photo: Alongside foggy and cold weather, light pollution was a serious problem as well; it was not easy to correct it on the photographs.
I rotated the camera so that the galaxy would fill the zone of vision as fully as possible; I also wanted the M110 galaxy on the photo. I am particularly pleased that the photograph shows small details about this small galaxy as well. During the process, I compiled images with different exposition times in order to make the brightness of the internal part of the galaxy balanced, yet to keep the dynamics of the picture.
Andromeda Galaxy, Messier 31, M31, NGC 224
R.A. 00 h 42 m 44 s Dec. +41° 16′ 9″
Spiral galaxy - Sb
2.5 million light-years
3.2° x 1°
220 000 light-years
Autumn and winter
13/10/2017; 20/10/2017; 18/11/2017; 16/12/2017
Total exposure time:
Tápióbicske, Pest, Hungary
Nikon D3300 (unmodified)
Sky-Watcher 150/750 mm Newtonian reflector
Sky-Watcher NEQ-5 Pro GoTo
ZWO ASI 120 MC camera - PHD2
Sky-Watcher f/5 coma corrector
Focal ratio, length:
f/4.5, 682 mm
24 x 300 s, 23 x 600 s
PixInsight, Adobe Lightroom, Adobe Photoshop