If you don’t have a GoTo Mount, it can be a challenge to find your Deep Sky Object (DSO) in the night sky. However, there are techniques to help you locate your target. In this blog, I will discuss several of these tips and techniques.
If you are not familiar with the term GoTo Mount, these type of mounts have a database of DSO locations. Once you enter in your location information and do a star alignment, you can simply punch in the catalog number (i.e. M42) and the mount will slew (move) to your target. If you are getting serious about this genre of photography, a GoTo Mount should be on your upgrade list.
Now what if you don’t have a GoTo Mount. Here are a few techniques / tips that may help.
Use Stellarium or another astronomy planning tool to plan out your shoot and find its location in the sky. Note the constellation where it is located, stars or patterns of stars it is near, when it rises and sets, and the direction of the constellation at the time you plan to photograph it.
You will also want to determine where you will set up your mount based on the location of the DSO, location of Polaris, and any objects (i.e. big trees) in your yard.
Cell Phone Apps
There are several apps for your cell phone where you can point your phone at the sky and locate stars, constellations, and DSOs in the sky. They also have search capabilities and the ability to change the date and time to help with future planning.
Two of my favorite apps are Sky Guide and Star Walk 2. These apps are inexpensive, so I have several of them on my phone.
Star Hopping is a technique where you use stars or recognizable patterns of stars to locate your targets in the night sky. This is easier to do on some targets than others. The best way to describe this technique is with a few examples.
The Constellation Orion
There are several DSOs located in the constellation Orion. Orion is easily recognizable by the 3 stars that make up Orion’s belt.
Orion’s Belt – Just above the left most star in Orion’s belt, you will find the Flame Nebula and directly below the left star you will find the Horsehead Nebula.
Orion’s Sword / Scabbard – Directly down from Orion’s belt you will see 3 stars that and M42 (Orion’s Nebula) that make up Orion’s Sword or scabbard. This can be seen with the naked eye and can be easily targeted with your camera.
The Pleiades Cluster
The Pleiades Cluster can be found by star hopping across several constellations. Start with Orion’s belt and follow it up thru the top star in Orion’s bow, past Aldebaran in Taurus and you will find a bright cluster of stars – The Pleiades Cluster. Pleiades can also be seen with the naked eye.
This technique can be less precise than using a GoTo Mount or computer software (Plate Solving) to find your target. Using a shorter focal length will be more forgiving in composing your target. For more information on planning your composition and focal length, check out my blog on the topic.
Take Test Shots
Take high ISO test shots to verify your targeting / composition. Look for patterns of stars and signs of your target. You can search for images of the object you are targeting on your cell phone for comparison.
If you are using imaging capturing software on your laptop, you can change the grain/exposure and stretch the image to assist in confirming the composition.
Written by Martin Belan
How to Set Up the Sky-Watcher Star Adventurer for a Deep Sky Astrophotography Shoot
Beginning Deep Sky Astrophotography – Planning Your Photo Shoot (DSO Targets)
Learning Deep Sky Astrophotography – Planning Your Composition