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... М30 < М31 > М32 ...

Spiral galaxy M31

Spiral galaxy M31 or Andromeda is in the constellation Andromeda (And).


Equatorial coordinates (epoch J2000):
Ra (α):00h42.8m, Dec (δ):+41° 16'

Visual magnitude: 3,4m - this object can be seen with the naked eye.
Distance from the galaxy M31 to the Sun is 2,57*106 light years
Angular size: 3,17°×1°
Class: Sb
External dimensions the galaxy M31 are about 157000 light years.
Number of stars: 1000x109
Estimated weight the galaxy: 300-400x109 suns
The mass of the central object (black hole): 140x106 suns

Discoverer: Known since antiquity, as visible to the naked eye in a really black sky. year.

The designation M31 in other catalogs: NGC 224

Optimum magnification for a telescope with observations of M31, depending on the aperture of the telescope (D), is about D/6-D/3. Higher magnifications of course add details, but lead to a strong drop in the brightness of the image, making it difficult to observe.

The best month for observing M31 is October. At this time, the object is at midnight near its highest point in the sky, that is, it is less affected by light from the lanterns and atmospheric distortions.

Мessier 30
Мessier 32

Nikolay Kurdyapin, astro-map.com  

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