Creating an Astro Image Part III – Selecting a Target

Ok, so we’ve got a rig that can do this, and software that can tell it how…so…what are we gonna shoot???

Target selection is part personal preference (I’m a fan of flowy knotty nebulae myself), part conditions (both physical : “There’s a tree in my way”, and “situational” : Humidty = lousy seeing = worse guiding) , part gear (That’s a faint target, it’ll need longer exposures, can my rig do that?) and timing (What’s visible in September?).

First place I like to start is a look at the “natural” conditions.  How much astronomical darkness do I have?  What are the moon phases? Beyond simple cloud cover, I’ll look at certain weather conditions of significance to astronomy, like seeing and transparency.

These things will impact the rig’s ability to focus tightly, guide well, and how long I can image on any given good night.  A fainter target needs more, longer exposures..if it’s only visible for 4 hours a night, that’s a tough ask.

Next, I’ll head over to DSO Browser.  This is a wonderful site that allows me to search for objects from dozens of catalogs, based on many of the factors outlined above.  I can narrow results by the object’s brightness, type, altitude above my horizon, direction, and so on.

This then lets me do things like say “Conditions look pretty good for a while, I can get good guiding, so I can allow a fainter target.  It’s heading toward winter, so I have longer evenings, so something that rises early and stays up longer is possible” and so on.

From there, then, I’ll select half a dozen or so candidates, and start simply googling them, or checking the sites of various other astrophotographers, to see how they’ve presented the image, or what filter choices they’ve made, and so on.  I’ve referenced Bill Snyder before…his site is an excellent resource for me, since he’s not only a prolific and talented imager, but he often includes in-depth details about the data acquisition that led to any given image, which helps me understand a target I may previously have been unfamiliar with.

Once all this is done, I’ve got a pretty good idea of 2-3 solid targets that I know fit my conditions and abilities, and are likely candidates for the upcoming 2-3 weeks.

So…drumroll please…

Just went through this process last night, and have settled on NGC 1491 as my next target, so that’s the one we’ll be documenting for the rest of the series!

Next post will show the setup and prep for a new target session, and kick off data collection!  SUCK UP ALL THE PHOTONS!

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