Now that the moon has started in intervene into the night sky, it's time to find suitable narrowband targets. Unfortunately, the spring season is considered "galaxy season", simply for the fact that the skies are dominated by galaxies and galaxy clusters. But, galaxies don't make very good narrowband targets. They tend to not put out light in the bandwidths used by amateurs, Ha, OIII and SII. The only exception being hAlpha light that is emitted by galaxies which have a lot of bright start-forming regions like Messier 82. But even these galaxies need to have LRGB data to make the picture complete.
Since the selection of narrowband targets in spring is slim, I turn to one of the last vestiges of winter, the constellationOrion and one of the most well-known dark nebulae, IC434, the Horsehead Nebula.
About 1500 light years from Earth, this is a smaller part of the huge Orion Molecular Cloud Complex that encompasses a good portion of the Orion constellation and consists of several different start forming regions, including the Messier 42, the Orion Nebula. While M42 is easily visible to the naked eye, the Horsehead is generally only visible in long-exposure photographs. Although, large aperture telescope and special filters may allow visual observers to see the outline. I, personally, have never see it.
This image is a stack of six 15-minute exposures through a 3nm Hydrogen Alpha filter. The telescope used is a Celestron HD1100 with an Apogee U16M CCD camera. Everything sits atop a Paramount ME german equatorial mount at Sugar Grove Observatory. The images were acquired using Maxim DL, stacked in Deep Sky Stacker and post-processed with Photoshop CS5.