STScI

Astrophotography under difficult conditions

It was once again clear, windy and to make matters worse not really dark due to the waning moon (brightness 55%). To highlight the structures of my desired objects Orion Nebula M42 and the Cirrus Nebula NGC 6960, an Optolong L-eXtreme bandpass filter was used.The nature of this filter makes it possible to image emission nebulae even in bright and light polluted skies. The L-eXtreme filter isolates the H-alpha and OIII emission lines, maximizing contrast and signal-to-noise ratio. The filter a dual band that passes H-alpha and OIII emission lines.

Objects this night.

The Messier 42 nebula is the brightest and most conspicuous part of a much larger cloud of gas and dust that stretches across the entire constellation of Orion. M42 is an active birthplace of young stars about 1600 light-years away. Considering this distance, the surrounding nebular cloud reaches a good 30 light-years. It consists of 60% hydrogen and 38% helium.

M13 is the brightest globular cluster in the northern sky. The globular cluster is considered the most beautiful of its kind in the northern hemisphere. It contains about 300,000 stars, has a diameter of one hundred light years and is 25,000 light years away from us.

The Cirrus Nebula NGC 6960 is only a small region of an emission and reflection nebula, located at a distance of about 1500 light-years in the constellation of Cygnus. The Cirrus Nebula is a supernova remnant. The arc-shaped part NGC 6960 is located next to the bright star 52 Cygni. This nebula consists of several filigree segments named NGC 6960, NGC 6979, NGC 9692, NGC 6995 and IC 1340.

Images were taken with a 10 inch Lacerta Newtonian telescope F4.7 and a Zwo Asi 2600 MC Pro Color camera with Optolong L-eXtreme bandpass filter.

Tracking Skywatcher EQ8

Guiding: Off Axis Guider with Zwo Asi 290 Mono and use of PHD

Exposure time 1- 2 hours.

For any photographer looking to maximize their limited time under a less than ideal night sky, using this filter is a real option. The effects are truly remarkable.

I am overwhelmed by the results that are possible within the shortest exposure time with this combination.

Text and images: Ralf Schmidt

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