One of quite a few globular clusters from the Messier catalogue in constellation Ophiuchus.

This one is about 30000 light years away and since we look here almost in direction to the Milky Ways center but a bit upwards from the galactic plane, its light must pass quite a lot of gas and dust to reach our eye. It is estimated that its brightness is attenuated by this dust by about two astronomic magnitudes, which is about a factor of 6.5.

As blue light is scattered by dust stronger than red light we see objects behind dust in a slightly reddish tone (as the sun becomes red just before touching the horizon).

This is the case for this star cluster and for quite some of the numerous fainter stars in this field.

The cluster itself is not as dense in its center as in many other brighter globular clusters.

But nevertheless it is a nice targets in these short nights.

Borg 90FL
1.08 Flattener
F=540mm
Baader broadband color filters RGB
ZWO ASI2600MM Pro
R: 14x180sec
G: 14x180sec
B: 14x180sec
Total integration time 2h6m
Bortle 4-5

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