NGC 5746 - Galaxy
On photographic images NGC 5746 looks simply beautiful: a very large "Edge On Galaxy" traversed by a very conspicuous dust lane.
It is a barred spiral galaxy of Hubble Type "SBb", with an apparent magnitude of 10.5mag and a size of 7.4'x1.3' arcmin in the constellation
Virgo. It was found in February of the year 1786 by F.W. Herschel.
The distance to NGC 5746 is given as 77...90 million light years. From this an absolute magnitude of M= -21.4mag can be calculated, which
corresponds to a luminosity of 32 billion suns. With a diameter of 170.000 lightyears the galaxy is even bigger than our Milky Way. Because
of its special orientation (EdgeOn) we can see that the central bulge is not roundish, but rather angular. This indicates a bar, at which we look
from the side. The rate of star formation is only moderately high and takes place in an inner ring with a diameter of 30,000 light-years.
Only one supernova could be observed so far: "SN 1983P" with a maximum brightness of 13mag.
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The object is located next to a brighter asterism, which looks just wonderful in a 20" telescope. You can immediately recognize a quite bright,
elongated line - the galaxy! The dust band, which is so prominent on images, is a little bit shy - and so it can be seen only in the central area at
a magnification of 270x. It then fades outward, but the galaxy disk on that side of the dust lane is quite well defined, a clear indication that
dust clouds are present here, even if you can't see them directly.
The core region appears a bit more "angular" than the bulge of other galaxies, but the shape is difficult to see. A faint stellar nucleus can also
be seen directly in the center. In the halo at the southern end of the galaxy a star can be seen that one might mistakenly think is a supernova. But
it is only a foreground star.
Overall, this is a great and little visited galaxy, that offers a lot of joy!
